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* [PATCH v3] Add "Backpatch" regions in wait_event_names.txt
@ 2024-03-18 08:34 Bertrand Drouvot <[email protected]>
0 siblings, 0 replies; 25+ messages in thread
From: Bertrand Drouvot @ 2024-03-18 08:34 UTC (permalink / raw)
When backpatching, adding an event will renumber others, which can make an
extension report the wrong event until recompiled. This is due to the fact that
generate-wait_event_types.pl sorts events to position them. The "Backpatch"
region added here ensures no ordering is done for the wait events found after
this delimiter.
---
.../activity/generate-wait_event_types.pl | 26 ++++++++++++++++++-
.../utils/activity/wait_event_names.txt | 18 ++++++++++++-
2 files changed, 42 insertions(+), 2 deletions(-)
100.0% src/backend/utils/activity/
diff --git a/src/backend/utils/activity/generate-wait_event_types.pl b/src/backend/utils/activity/generate-wait_event_types.pl
index f1adf0e8e7..d129d94889 100644
--- a/src/backend/utils/activity/generate-wait_event_types.pl
+++ b/src/backend/utils/activity/generate-wait_event_types.pl
@@ -38,7 +38,9 @@ die "Not possible to specify --docs and --code simultaneously"
open my $wait_event_names, '<', $ARGV[0] or die;
+my @backpatch_lines;
my @lines;
+my $backpatch = 0;
my $section_name;
my $note;
my $note_name;
@@ -59,10 +61,26 @@ while (<$wait_event_names>)
{
$section_name = $_;
$section_name =~ s/^.*- //;
+ $backpatch = 0;
next;
}
- push(@lines, $section_name . "\t" . $_);
+ # Are we dealing with backpatch wait events?
+ if (/^Backpatch:$/)
+ {
+ $backpatch = 1;
+ next;
+ }
+
+ # Backpatch wait events won't be sorted during code generation
+ if ($gen_code && $backpatch)
+ {
+ push(@backpatch_lines, $section_name . "\t" . $_);
+ }
+ else
+ {
+ push(@lines, $section_name . "\t" . $_);
+ }
}
# Sort the lines based on the second column.
@@ -70,6 +88,12 @@ while (<$wait_event_names>)
my @lines_sorted =
sort { uc((split(/\t/, $a))[1]) cmp uc((split(/\t/, $b))[1]) } @lines;
+# If we are generating code then concat @lines_sorted and @backpatch_lines.
+if ($gen_code)
+{
+ push(@lines_sorted, @backpatch_lines);
+}
+
# Read the sorted lines and populate the hash table
foreach my $line (@lines_sorted)
{
diff --git a/src/backend/utils/activity/wait_event_names.txt b/src/backend/utils/activity/wait_event_names.txt
index c08e00d1d6..0c4788fe77 100644
--- a/src/backend/utils/activity/wait_event_names.txt
+++ b/src/backend/utils/activity/wait_event_names.txt
@@ -24,7 +24,10 @@
# SGML tables of wait events for inclusion in the documentation.
#
# When adding a new wait event, make sure it is placed in the appropriate
-# ClassName section.
+# ClassName section. Put it in its natural position in the master branch, and
+# then put it in the "Backpatch:" region for any other branch (should the wait
+# event be backpatched).
+# Ensure that the backpatch regions are always empty on the master branch.
#
# WaitEventLWLock and WaitEventLock have their own C code for their wait event
# enums and function names. Hence, for these, only the SGML documentation is
@@ -61,6 +64,7 @@ WAL_SENDER_MAIN "Waiting in main loop of WAL sender process."
WAL_SUMMARIZER_WAL "Waiting in WAL summarizer for more WAL to be generated."
WAL_WRITER_MAIN "Waiting in main loop of WAL writer process."
+Backpatch:
#
# Wait Events - Client
@@ -82,6 +86,7 @@ WAIT_FOR_STANDBY_CONFIRMATION "Waiting for WAL to be received and flushed by the
WAL_SENDER_WAIT_FOR_WAL "Waiting for WAL to be flushed in WAL sender process."
WAL_SENDER_WRITE_DATA "Waiting for any activity when processing replies from WAL receiver in WAL sender process."
+Backpatch:
#
# Wait Events - IPC
@@ -149,6 +154,7 @@ WAL_RECEIVER_WAIT_START "Waiting for startup process to send initial data for st
WAL_SUMMARY_READY "Waiting for a new WAL summary to be generated."
XACT_GROUP_UPDATE "Waiting for the group leader to update transaction status at end of a parallel operation."
+Backpatch:
#
# Wait Events - Timeout
@@ -169,6 +175,7 @@ VACUUM_DELAY "Waiting in a cost-based vacuum delay point."
VACUUM_TRUNCATE "Waiting to acquire an exclusive lock to truncate off any empty pages at the end of a table vacuumed."
WAL_SUMMARIZER_ERROR "Waiting after a WAL summarizer error."
+Backpatch:
#
# Wait Events - IO
@@ -256,6 +263,7 @@ WAL_SYNC "Waiting for a WAL file to reach durable storage."
WAL_SYNC_METHOD_ASSIGN "Waiting for data to reach durable storage while assigning a new WAL sync method."
WAL_WRITE "Waiting for a write to a WAL file."
+Backpatch:
#
# Wait Events - Buffer Pin
@@ -265,6 +273,7 @@ Section: ClassName - WaitEventBufferPin
BUFFER_PIN "Waiting to acquire an exclusive pin on a buffer."
+Backpatch:
#
# Wait Events - Extension
@@ -274,6 +283,8 @@ Section: ClassName - WaitEventExtension
Extension "Waiting in an extension."
+Backpatch:
+
#
# Wait Events - LWLock
#
@@ -330,6 +341,8 @@ DSMRegistry "Waiting to read or update the dynamic shared memory registry."
InjectionPoint "Waiting to read or update information related to injection points."
SerialControl "Waiting to read or update shared <filename>pg_serial</filename> state."
+# Don't create a Backpatch region here.
+
#
# END OF PREDEFINED LWLOCKS (DO NOT CHANGE THIS LINE)
#
@@ -377,6 +390,7 @@ SerialSLRU "Waiting to access the serializable transaction conflict SLRU cache."
SubtransSLRU "Waiting to access the sub-transaction SLRU cache."
XactSLRU "Waiting to access the transaction status SLRU cache."
+# Don't create a Backpatch region here.
#
# Wait Events - Lock
@@ -399,3 +413,5 @@ object "Waiting to acquire a lock on a non-relation database object."
userlock "Waiting to acquire a user lock."
advisory "Waiting to acquire an advisory user lock."
applytransaction "Waiting to acquire a lock on a remote transaction being applied by a logical replication subscriber."
+
+Backpatch:
--
2.34.1
--m1fyrkxSXqjY+FO1--
^ permalink raw reply [nested|flat] 25+ messages in thread
* Re: Slow catchup of 2PC (twophase) transactions on replica in LR
@ 2024-05-08 00:07 Peter Smith <[email protected]>
0 siblings, 1 reply; 25+ messages in thread
From: Peter Smith @ 2024-05-08 00:07 UTC (permalink / raw)
To: Hayato Kuroda (Fujitsu) <[email protected]>; +Cc: [email protected] <[email protected]>; Amit Kapila <[email protected]>; Ajin Cherian <[email protected]>; Давыдов Виталий <[email protected]>
Hi, Here are some review comments for patch v6-0001
======
Commit message
1.
This patch allows user to alter two_phase option
/allows user/allows the user/
/to alter two_phase option/to alter the 'two_phase' option/
======
doc/src/sgml/ref/alter_subscription.sgml
2.
<literal>two_phase</literal> can be altered only for disabled subscription.
SUGGEST
The <literal>two_phase</literal> parameter can only be altered when
the subscription is disabled.
======
src/backend/access/transam/twophase.c
3. checkGid
+
+/*
+ * checkGid
+ */
+static bool
+checkGid(char *gid, Oid subid)
+{
+ int ret;
+ Oid subid_written,
+ xid;
+
+ ret = sscanf(gid, "pg_gid_%u_%u", &subid_written, &xid);
+
+ if (ret != 2 || subid != subid_written)
+ return false;
+
+ return true;
+}
3a.
The function comment should give more explanation of what it does. I
think this function is the counterpart of the TwoPhaseTransactionGid()
function of worker.c so the comment can say that too.
~
3b.
Indeed, perhaps the function name should be similar to
TwoPhaseTransactionGid. e.g. call it like
IsTwoPhaseTransactionGidForSubid?
~
3c.
Probably 'xid' should be TransactionId instead of Oid.
~
3d.
Why not have a single return?
SUGGESTION
return (ret == 2 && subid = subid_written);
~
3e.
I am wondering if the existing TwoPhaseTransactionGid function
currently in worker.c should be moved here because IMO these 2
functions belong together and twophase.c seems the right place to put
them.
~~~
4.
+LookupGXactBySubid(Oid subid)
+{
+ bool found = false;
+
+ LWLockAcquire(TwoPhaseStateLock, LW_SHARED);
+ for (int i = 0; i < TwoPhaseState->numPrepXacts; i++)
+ {
+ GlobalTransaction gxact = TwoPhaseState->prepXacts[i];
+
+ /* Ignore not-yet-valid GIDs. */
+ if (gxact->valid && checkGid(gxact->gid, subid))
+ {
+ found = true;
+ break;
+ }
+ }
+ LWLockRelease(TwoPhaseStateLock);
+ return found;
+}
AFAIK the gxact also has the 'xid' available, so won't it be better to
pass BOTH the 'xid' and 'subid' to the checkGid so you can do a full
comparison instead of comparing only the subid part of the gid?
======
src/backend/commands/subscriptioncmds.c
5. AlterSubscription
+ /* XXX */
+ if (IsSet(opts.specified_opts, SUBOPT_TWOPHASE_COMMIT))
+ {
The "XXX" comment looks like it is meant to say something more...
~~~
6.
+ /*
+ * two_phase can be only changed for disabled
+ * subscriptions
+ */
+ if (form->subenabled)
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("cannot set %s for enabled subscription",
+ "two_phase")));
6a.
Should this have a more comprehensive comment giving the reason like
the 'failover' option has?
~~~
6b.
Maybe this should include a "translator" comment to say don't
translate the option name.
~~~
7.
+ /* Check whether the number of prepared transactions */
+ if (!opts.twophase &&
+ form->subtwophasestate == LOGICALREP_TWOPHASE_STATE_ENABLED &&
+ LookupGXactBySubid(subid))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("cannot disable two_phase when uncommitted prepared
transactions present")));
+
7a.
The first comment seems to be an incomplete sentence. I think it
should say something a bit like:
two_phase cannot be disabled if there are any uncommitted prepared
transactions present.
~
7b.
Also, if ereport occurs what is the user supposed to do about it?
Shouldn't the ereport include some errhint with appropriate advice?
~~~
8.
+ /*
+ * The changed failover option of the slot can't be rolled
+ * back.
+ */
+ PreventInTransactionBlock(isTopLevel, "ALTER SUBSCRIPTION ... SET
(two_phase)");
+
+ /* Change system catalog acoordingly */
+ values[Anum_pg_subscription_subtwophasestate - 1] =
+ CharGetDatum(opts.twophase ?
+ LOGICALREP_TWOPHASE_STATE_PENDING :
+ LOGICALREP_TWOPHASE_STATE_DISABLED);
+ replaces[Anum_pg_subscription_subtwophasestate - 1] = true;
+ }
Typo I think: /failover option/two_phase option/
======
.../libpqwalreceiver/libpqwalreceiver.c
9.
static void
libpqrcv_alter_slot(WalReceiverConn *conn, const char *slotname,
- bool failover)
+ bool two_phase, bool failover)
Same comment as mentioned elsewhere (#15), IMO the new 'two_phase'
parameter should be last.
======
src/backend/replication/logical/launcher.c
10.
+/*
+ * Stop all the subscription workers.
+ */
+void
+logicalrep_workers_stop(Oid subid)
+{
+ List *subworkers;
+ ListCell *lc;
+
+ LWLockAcquire(LogicalRepWorkerLock, LW_SHARED);
+ subworkers = logicalrep_workers_find(subid, false);
+ LWLockRelease(LogicalRepWorkerLock);
+ foreach(lc, subworkers)
+ {
+ LogicalRepWorker *w = (LogicalRepWorker *) lfirst(lc);
+
+ logicalrep_worker_stop(w->subid, w->relid);
+ }
+ list_free(subworkers);
+}
I was confused by the logicalrep_workers_find(subid, false). IIUC the
'false' means everything (instead of 'only_running') but then I don't
know why we want to "stop" anything that is NOT running. OTOH I see
that this code was extracted from where it was previously inlined in
subscriptioncmds.c, so maybe the 'false' is necessary for another
reason? At least maybe some explanatory comment is needed for why you
are passing this flag as false?
======
src/backend/replication/logical/worker.c
11.
- /* two-phase should not be altered */
+ /* two-phase should not be altered while the worker exists */
Assert(newsub->twophasestate == MySubscription->twophasestate);
/should not/cannot/
======
src/backend/replication/slot.c
12.
void
-ReplicationSlotAlter(const char *name, bool failover)
+ReplicationSlotAlter(const char *name, bool two_phase, bool failover)
Same comment as mentioned elsewhere (#15), IMO the new 'two_phase'
parameter should be last.
~~~
13.
+ if (MyReplicationSlot->data.two_phase != two_phase)
+ {
+ SpinLockAcquire(&MyReplicationSlot->mutex);
+ MyReplicationSlot->data.two_phase = two_phase;
+ SpinLockRelease(&MyReplicationSlot->mutex);
+
+ update_slot = true;
+ }
+
+
if (MyReplicationSlot->data.failover != failover)
{
SpinLockAcquire(&MyReplicationSlot->mutex);
MyReplicationSlot->data.failover = failover;
SpinLockRelease(&MyReplicationSlot->mutex);
+ update_slot = true;
+ }
13a.
Doesn't it make more sense for the whole check/set to be "atomic",
i.e. put the mutex also around the check?
SUGGEST
SpinLockAcquire(&MyReplicationSlot->mutex);
if (MyReplicationSlot->data.two_phase != two_phase)
{
MyReplicationSlot->data.two_phase = two_phase;
update_slot = true;
}
SpinLockRelease(&MyReplicationSlot->mutex);
~
Also, (if you agree with the above) why not include both checks
(two_phase and failover) within the same mutex instead of
acquiring/releasing it twice:
SUGGEST
SpinLockAcquire(&MyReplicationSlot->mutex);
if (MyReplicationSlot->data.two_phase != two_phase)
{
MyReplicationSlot->data.two_phase = two_phase;
update_slot = true;
}
if (MyReplicationSlot->data.failover != failover)
{
MyReplicationSlot->data.failover = failover;
update_slot = true;
}
SpinLockAcquire(&MyReplicationSlot->mutex);
~~~
13b.
There are double blank lines after the first if-block.
======
src/backend/replication/walsender.c
14.
static void
-ParseAlterReplSlotOptions(AlterReplicationSlotCmd *cmd, bool *failover)
+ParseAlterReplSlotOptions(AlterReplicationSlotCmd *cmd,
+ bool *two_phase, bool *failover)
Same comment as mentioned elsewhere (#15), IMO the new 'two_phase'
parameter should be last.
======
src/include/replication/walreceiver.h
15.
typedef void (*walrcv_alter_slot_fn) (WalReceiverConn *conn,
const char *slotname,
+ bool two_phase,
bool failover);
Somehow, I feel it is more normal to add the new code (the 'two_phase'
parameter) at the END, instead of into the middle of the existing
parameters. It also keeps it alphabetical which makes it consistent
with other places like the tab-completion code.
This comment about swapping the order (putting new stuff last) will
propagate changes to lots of other related places. I refer to this
comment in a few other places in this post but there are probably more
the same that I missed.
======
src/test/regress/sql/subscription.sql
16.
I know you do this already in the TAP test, but doesn't the test case
to demonstrate that 'two-phase' option can be altered when the
subscription is disabled actually belong here in the regression
instead?
======
src/test/subscription/t/021_twophase.pl
17.
+# Disable the subscription and alter it to two_phase = false,
+# verify that the altered subscription reflects the two_phase option.
/verify/then verify/
~~~
18.
+# Now do a prepare on publisher and make sure that it is not replicated.
+$node_subscriber->safe_psql('postgres', "DROP SUBSCRIPTION tap_sub");
+$node_publisher->safe_psql(
+ 'postgres', qq{
+ BEGIN;
+ INSERT INTO tab_copy VALUES (100);
+ PREPARE TRANSACTION 'newgid';
+ });
+
18a.
/on publisher/on the publisher/
18b.
What is that "DROP SUBSCRIPTION tap_sub" doing here? It seems
misplaced under this comment.
~~~
19.
+# Make sure that there is 0 prepared transaction on the subscriber
+$result = $node_subscriber->safe_psql('postgres',
+ "SELECT count(*) FROM pg_prepared_xacts;");
+is($result, qq(0), 'transaction is prepared on subscriber');
19a.
SUGGESTION
Make sure there are no prepared transactions on the subscriber
~~~
19b.
/'transaction is prepared on subscriber'/'should be no prepared
transactions on subscriber'/
~~~
20.
+# Made sure that the commited transaction is replicated.
/Made sure/Make sure/
/commited/committed/
~~~
21.
+# Make sure that the two-phase is enabled on the subscriber
+$result = $node_subscriber->safe_psql('postgres',
+ "SELECT subtwophasestate FROM pg_subscription WHERE subname = 'tap_sub_copy';"
+);
+is($result, qq(e), 'two-phase is disabled');
The 'two-phase is disabled' is the identical message used in the
opposite case earlier, so something is amiss. Maybe this one should
say 'two-phase should be enabled' and the earlier counterpart should
say 'two-phase should be disabled'.
======
Kind Regards,
Peter Smith
Fujitsu Australia
^ permalink raw reply [nested|flat] 25+ messages in thread
* RE: Slow catchup of 2PC (twophase) transactions on replica in LR
@ 2024-05-08 08:26 Hayato Kuroda (Fujitsu) <[email protected]>
parent: Peter Smith <[email protected]>
0 siblings, 4 replies; 25+ messages in thread
From: Hayato Kuroda (Fujitsu) @ 2024-05-08 08:26 UTC (permalink / raw)
To: 'Peter Smith' <[email protected]>; +Cc: [email protected] <[email protected]>; Amit Kapila <[email protected]>; Ajin Cherian <[email protected]>; Давыдов Виталий <[email protected]>
Dear Peter,
Thanks for reviewing! Here are updated patches.
I updated patches only for HEAD.
> ======
> Commit message
>
> 1.
> This patch allows user to alter two_phase option
>
> /allows user/allows the user/
>
> /to alter two_phase option/to alter the 'two_phase' option/
Fixed.
> ======
> doc/src/sgml/ref/alter_subscription.sgml
>
> 2.
> <literal>two_phase</literal> can be altered only for disabled subscription.
>
> SUGGEST
> The <literal>two_phase</literal> parameter can only be altered when
> the subscription is disabled.
Fixed.
> ======
> src/backend/access/transam/twophase.c
>
> 3. checkGid
> +
> +/*
> + * checkGid
> + */
> +static bool
> +checkGid(char *gid, Oid subid)
> +{
> + int ret;
> + Oid subid_written,
> + xid;
> +
> + ret = sscanf(gid, "pg_gid_%u_%u", &subid_written, &xid);
> +
> + if (ret != 2 || subid != subid_written)
> + return false;
> +
> + return true;
> +}
>
> 3a.
> The function comment should give more explanation of what it does. I
> think this function is the counterpart of the TwoPhaseTransactionGid()
> function of worker.c so the comment can say that too.
Comments were updated.
> 3b.
> Indeed, perhaps the function name should be similar to
> TwoPhaseTransactionGid. e.g. call it like
> IsTwoPhaseTransactionGidForSubid?
Replaced to IsTwoPhaseTransactionGidForSubid().
> 3c.
> Probably 'xid' should be TransactionId instead of Oid.
Right, fixed.
> 3d.
> Why not have a single return?
>
> SUGGESTION
> return (ret == 2 && subid = subid_written);
Fixed.
> 3e.
> I am wondering if the existing TwoPhaseTransactionGid function
> currently in worker.c should be moved here because IMO these 2
> functions belong together and twophase.c seems the right place to put
> them.
+1, moved.
> ~~~
>
> 4.
> +LookupGXactBySubid(Oid subid)
> +{
> + bool found = false;
> +
> + LWLockAcquire(TwoPhaseStateLock, LW_SHARED);
> + for (int i = 0; i < TwoPhaseState->numPrepXacts; i++)
> + {
> + GlobalTransaction gxact = TwoPhaseState->prepXacts[i];
> +
> + /* Ignore not-yet-valid GIDs. */
> + if (gxact->valid && checkGid(gxact->gid, subid))
> + {
> + found = true;
> + break;
> + }
> + }
> + LWLockRelease(TwoPhaseStateLock);
> + return found;
> +}
>
> AFAIK the gxact also has the 'xid' available, so won't it be better to
> pass BOTH the 'xid' and 'subid' to the checkGid so you can do a full
> comparison instead of comparing only the subid part of the gid?
IIUC, the xid written in the gxact means the transaction id on the subscriber,
but formatted GID has xid on the publisher. So the value cannot be used.
> ======
> src/backend/commands/subscriptioncmds.c
>
> 5. AlterSubscription
>
> + /* XXX */
> + if (IsSet(opts.specified_opts, SUBOPT_TWOPHASE_COMMIT))
> + {
>
> The "XXX" comment looks like it is meant to say something more...
This flag was used only for me, removed.
> ~~~
>
> 6.
> + /*
> + * two_phase can be only changed for disabled
> + * subscriptions
> + */
> + if (form->subenabled)
> + ereport(ERROR,
> + (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
> + errmsg("cannot set %s for enabled subscription",
> + "two_phase")));
>
> 6a.
> Should this have a more comprehensive comment giving the reason like
> the 'failover' option has?
Modified, but it is almost the same as failover's one.
> 6b.
> Maybe this should include a "translator" comment to say don't
> translate the option name.
Hmm, but other parts in AlterSubscription() does not have.
For now, I kept current style.
> ~~~
>
> 7.
> + /* Check whether the number of prepared transactions */
> + if (!opts.twophase &&
> + form->subtwophasestate == LOGICALREP_TWOPHASE_STATE_ENABLED
> &&
> + LookupGXactBySubid(subid))
> + ereport(ERROR,
> + (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
> + errmsg("cannot disable two_phase when uncommitted prepared
> transactions present")));
> +
>
> 7a.
> The first comment seems to be an incomplete sentence. I think it
> should say something a bit like:
> two_phase cannot be disabled if there are any uncommitted prepared
> transactions present.
Modified, but this part would be replaced by upcoming patches.
> 7b.
> Also, if ereport occurs what is the user supposed to do about it?
> Shouldn't the ereport include some errhint with appropriate advice?
The hint was added, but this part would be replaced by upcoming patches.
> ~~~
>
> 8.
> + /*
> + * The changed failover option of the slot can't be rolled
> + * back.
> + */
> + PreventInTransactionBlock(isTopLevel, "ALTER SUBSCRIPTION ... SET
> (two_phase)");
> +
> + /* Change system catalog acoordingly */
> + values[Anum_pg_subscription_subtwophasestate - 1] =
> + CharGetDatum(opts.twophase ?
> + LOGICALREP_TWOPHASE_STATE_PENDING :
> + LOGICALREP_TWOPHASE_STATE_DISABLED);
> + replaces[Anum_pg_subscription_subtwophasestate - 1] = true;
> + }
>
> Typo I think: /failover option/two_phase option/
Right, fixed.
> ======
> .../libpqwalreceiver/libpqwalreceiver.c
>
> 9.
> static void
> libpqrcv_alter_slot(WalReceiverConn *conn, const char *slotname,
> - bool failover)
> + bool two_phase, bool failover)
>
> Same comment as mentioned elsewhere (#15), IMO the new 'two_phase'
> parameter should be last.
Fixed. Also, some ordering of declarations and if-blocks were also changed.
In later part, I did not reply similar comments but I addressed all of them.
> ======
> src/backend/replication/logical/launcher.c
>
> 10.
> +/*
> + * Stop all the subscription workers.
> + */
> +void
> +logicalrep_workers_stop(Oid subid)
> +{
> + List *subworkers;
> + ListCell *lc;
> +
> + LWLockAcquire(LogicalRepWorkerLock, LW_SHARED);
> + subworkers = logicalrep_workers_find(subid, false);
> + LWLockRelease(LogicalRepWorkerLock);
> + foreach(lc, subworkers)
> + {
> + LogicalRepWorker *w = (LogicalRepWorker *) lfirst(lc);
> +
> + logicalrep_worker_stop(w->subid, w->relid);
> + }
> + list_free(subworkers);
> +}
>
> I was confused by the logicalrep_workers_find(subid, false). IIUC the
> 'false' means everything (instead of 'only_running') but then I don't
> know why we want to "stop" anything that is NOT running. OTOH I see
> that this code was extracted from where it was previously inlined in
> subscriptioncmds.c, so maybe the 'false' is necessary for another
> reason? At least maybe some explanatory comment is needed for why you
> are passing this flag as false?
Sorry, let me give time for more investigation around here. For now,
I added "XXX" mark.
I think it is listed just in case, but there may be a timing issue.
> ======
> src/backend/replication/logical/worker.c
>
> 11.
> - /* two-phase should not be altered */
> + /* two-phase should not be altered while the worker exists */
> Assert(newsub->twophasestate == MySubscription->twophasestate);
> /should not/cannot/
Fixed.
> ~~~
>
> 13.
> + if (MyReplicationSlot->data.two_phase != two_phase)
> + {
> + SpinLockAcquire(&MyReplicationSlot->mutex);
> + MyReplicationSlot->data.two_phase = two_phase;
> + SpinLockRelease(&MyReplicationSlot->mutex);
> +
> + update_slot = true;
> + }
> +
> +
> if (MyReplicationSlot->data.failover != failover)
> {
> SpinLockAcquire(&MyReplicationSlot->mutex);
> MyReplicationSlot->data.failover = failover;
> SpinLockRelease(&MyReplicationSlot->mutex);
>
> + update_slot = true;
> + }
>
> 13a.
> Doesn't it make more sense for the whole check/set to be "atomic",
> i.e. put the mutex also around the check?
>
> SUGGEST
> SpinLockAcquire(&MyReplicationSlot->mutex);
> if (MyReplicationSlot->data.two_phase != two_phase)
> {
> MyReplicationSlot->data.two_phase = two_phase;
> update_slot = true;
> }
> SpinLockRelease(&MyReplicationSlot->mutex);
>
> ~
>
> Also, (if you agree with the above) why not include both checks
> (two_phase and failover) within the same mutex instead of
> acquiring/releasing it twice:
>
> SUGGEST
> SpinLockAcquire(&MyReplicationSlot->mutex);
> if (MyReplicationSlot->data.two_phase != two_phase)
> {
> MyReplicationSlot->data.two_phase = two_phase;
> update_slot = true;
> }
> if (MyReplicationSlot->data.failover != failover)
> {
> MyReplicationSlot->data.failover = failover;
> update_slot = true;
> }
> SpinLockAcquire(&MyReplicationSlot->mutex);
Hmm. According to comments atop ReplicationSlot, backends which own the slot do
not have to set mutex for reading attributes. Concurrent backends, which do not
acquire the slot, must set the mutex lock before the read. Based on the manner,
I want to keep current style.
```
* - Individual fields are protected by mutex where only the backend owning
* the slot is authorized to update the fields from its own slot. The
* backend owning the slot does not need to take this lock when reading its
* own fields, while concurrent backends not owning this slot should take the
* lock when reading this slot's data.
*/
typedef struct ReplicationSlot
```
> 13b.
> There are double blank lines after the first if-block.
Removed.
> ======
> src/test/regress/sql/subscription.sql
>
> 16.
> I know you do this already in the TAP test, but doesn't the test case
> to demonstrate that 'two-phase' option can be altered when the
> subscription is disabled actually belong here in the regression
> instead?
Actually it cannot be done at main regression test. Because altering two_phase
requires the connection between pub/sub, but it is not established in subscription.sql
file. Succeeded case for altering failover has not been tested neither, and
I think they have same reason.
> src/test/subscription/t/021_twophase.pl
>
> 17.
> +# Disable the subscription and alter it to two_phase = false,
> +# verify that the altered subscription reflects the two_phase option.
>
> /verify/then verify/
Fixed.
> 18.
> +# Now do a prepare on publisher and make sure that it is not replicated.
> +$node_subscriber->safe_psql('postgres', "DROP SUBSCRIPTION tap_sub");
> +$node_publisher->safe_psql(
> + 'postgres', qq{
> + BEGIN;
> + INSERT INTO tab_copy VALUES (100);
> + PREPARE TRANSACTION 'newgid';
> + });
> +
>
> 18a.
> /on publisher/on the publisher/
Fixed.
> 18b.
> What is that "DROP SUBSCRIPTION tap_sub" doing here? It seems
> misplaced under this comment.
The subscription must be dropped because it also prepares a transaction.
Moved before the test case and added comments.
> 19.
> +# Make sure that there is 0 prepared transaction on the subscriber
> +$result = $node_subscriber->safe_psql('postgres',
> + "SELECT count(*) FROM pg_prepared_xacts;");
> +is($result, qq(0), 'transaction is prepared on subscriber');
>
> 19a.
> SUGGESTION
> Make sure there are no prepared transactions on the subscriber
Fixed.
> 19b.
> /'transaction is prepared on subscriber'/'should be no prepared
> transactions on subscriber'/
Replaced/
> 20.
> +# Made sure that the commited transaction is replicated.
>
> /Made sure/Make sure/
>
> /commited/committed/
Fixed.
> 21.
> +# Make sure that the two-phase is enabled on the subscriber
> +$result = $node_subscriber->safe_psql('postgres',
> + "SELECT subtwophasestate FROM pg_subscription WHERE subname =
> 'tap_sub_copy';"
> +);
> +is($result, qq(e), 'two-phase is disabled');
>
> The 'two-phase is disabled' is the identical message used in the
> opposite case earlier, so something is amiss. Maybe this one should
> say 'two-phase should be enabled' and the earlier counterpart should
> say 'two-phase should be disabled'.
Both of them were fixed.
Best Regards,
Hayato Kuroda
FUJITSU LIMITED
https://www.fujitsu.com/
Attachments:
[application/octet-stream] v7-0001-Allow-altering-of-two_phase-option-of-a-SUBSCRIPT.patch (25.5K, ../../OSBPR01MB2552521ABDBC2F995FBACDF7F5E52@OSBPR01MB2552.jpnprd01.prod.outlook.com/2-v7-0001-Allow-altering-of-two_phase-option-of-a-SUBSCRIPT.patch)
download | inline diff:
From e5e7a64c5521c4603490042f451228b32233a72a Mon Sep 17 00:00:00 2001
From: Ajin Cherian <[email protected]>
Date: Fri, 5 Apr 2024 06:47:18 -0400
Subject: [PATCH v7 1/4] Allow altering of two_phase option of a SUBSCRIPTION
This patch allows the user to alter the 'two_phase' option of a subscriber provided no
uncommitted prepared transactions are pending on that subscription.
Author: Cherian Ajin, Hayato Kuroda
---
doc/src/sgml/ref/alter_subscription.sgml | 12 ++--
src/backend/access/transam/twophase.c | 61 ++++++++++++++++
src/backend/commands/subscriptioncmds.c | 68 ++++++++++++++----
.../libpqwalreceiver/libpqwalreceiver.c | 9 +--
src/backend/replication/logical/launcher.c | 22 ++++++
src/backend/replication/logical/worker.c | 21 +-----
src/backend/replication/slot.c | 18 ++++-
src/backend/replication/walsender.c | 18 ++++-
src/bin/psql/tab-complete.c | 2 +-
src/include/access/twophase.h | 5 ++
src/include/replication/slot.h | 3 +-
src/include/replication/walreceiver.h | 11 +--
src/include/replication/worker_internal.h | 1 +
src/test/regress/expected/subscription.out | 5 +-
src/test/regress/sql/subscription.sql | 5 +-
src/test/subscription/t/021_twophase.pl | 71 ++++++++++++++++++-
16 files changed, 269 insertions(+), 63 deletions(-)
diff --git a/doc/src/sgml/ref/alter_subscription.sgml b/doc/src/sgml/ref/alter_subscription.sgml
index a78c1c3a47..88e9a72147 100644
--- a/doc/src/sgml/ref/alter_subscription.sgml
+++ b/doc/src/sgml/ref/alter_subscription.sgml
@@ -68,8 +68,9 @@ ALTER SUBSCRIPTION <replaceable class="parameter">name</replaceable> RENAME TO <
<para>
Commands <command>ALTER SUBSCRIPTION ... REFRESH PUBLICATION</command>,
<command>ALTER SUBSCRIPTION ... {SET|ADD|DROP} PUBLICATION ...</command>
- with <literal>refresh</literal> option as <literal>true</literal> and
- <command>ALTER SUBSCRIPTION ... SET (failover = on|off)</command>
+ with <literal>refresh</literal> option as <literal>true</literal>,
+ <command>ALTER SUBSCRIPTION ... SET (failover = on|off)</command> and
+ <command>ALTER SUBSCRIPTION ... SET (two_phase = on|off)</command>
cannot be executed inside a transaction block.
These commands also cannot be executed when the subscription has
@@ -228,9 +229,12 @@ ALTER SUBSCRIPTION <replaceable class="parameter">name</replaceable> RENAME TO <
<link linkend="sql-createsubscription-params-with-disable-on-error"><literal>disable_on_error</literal></link>,
<link linkend="sql-createsubscription-params-with-password-required"><literal>password_required</literal></link>,
<link linkend="sql-createsubscription-params-with-run-as-owner"><literal>run_as_owner</literal></link>,
- <link linkend="sql-createsubscription-params-with-origin"><literal>origin</literal></link>, and
- <link linkend="sql-createsubscription-params-with-failover"><literal>failover</literal></link>.
+ <link linkend="sql-createsubscription-params-with-origin"><literal>origin</literal></link>,
+ <link linkend="sql-createsubscription-params-with-failover"><literal>failover</literal></link>, and
+ <link linkend="sql-createsubscription-params-with-two-phase"><literal>two_phase</literal></link>.
Only a superuser can set <literal>password_required = false</literal>.
+ The <literal>two_phase</literal> parameter can only be altered when the
+ subscription is disabled.
</para>
<para>
diff --git a/src/backend/access/transam/twophase.c b/src/backend/access/transam/twophase.c
index 8090ac9fc1..a67a8c48aa 100644
--- a/src/backend/access/transam/twophase.c
+++ b/src/backend/access/transam/twophase.c
@@ -2682,3 +2682,64 @@ LookupGXact(const char *gid, XLogRecPtr prepare_end_lsn,
LWLockRelease(TwoPhaseStateLock);
return found;
}
+
+/*
+ * TwoPhaseTransactionGid
+ * Form the prepared transaction GID for two_phase transactions.
+ *
+ * Return the GID in the supplied buffer.
+ */
+void
+TwoPhaseTransactionGid(Oid subid, TransactionId xid, char *gid, int szgid)
+{
+ Assert(subid != InvalidRepOriginId);
+
+ if (!TransactionIdIsValid(xid))
+ ereport(ERROR,
+ (errcode(ERRCODE_PROTOCOL_VIOLATION),
+ errmsg_internal("invalid two-phase transaction ID")));
+
+ snprintf(gid, szgid, "pg_gid_%u_%u", subid, xid);
+}
+
+/*
+ * IsTwoPhaseTransactionGidForSubid
+ * Check whether the given GID is formed by TwoPhaseTransactionGid.
+ */
+static bool
+IsTwoPhaseTransactionGidForSubid(Oid subid, char *gid)
+{
+ int ret;
+ Oid subid_written;
+ TransactionId xid;
+
+ ret = sscanf(gid, "pg_gid_%u_%u", &subid_written, &xid);
+
+ return (ret == 2 && subid == subid_written);
+}
+
+/*
+ * LookupGXactBySubid
+ * Check if the prepared transaction done by apply worker exists.
+ */
+bool
+LookupGXactBySubid(Oid subid)
+{
+ bool found = false;
+
+ LWLockAcquire(TwoPhaseStateLock, LW_SHARED);
+ for (int i = 0; i < TwoPhaseState->numPrepXacts; i++)
+ {
+ GlobalTransaction gxact = TwoPhaseState->prepXacts[i];
+
+ /* Ignore not-yet-valid GIDs. */
+ if (gxact->valid &&
+ IsTwoPhaseTransactionGidForSubid(subid, gxact->gid))
+ {
+ found = true;
+ break;
+ }
+ }
+ LWLockRelease(TwoPhaseStateLock);
+ return found;
+}
diff --git a/src/backend/commands/subscriptioncmds.c b/src/backend/commands/subscriptioncmds.c
index e407428dbc..1a2f0c1e64 100644
--- a/src/backend/commands/subscriptioncmds.c
+++ b/src/backend/commands/subscriptioncmds.c
@@ -16,6 +16,7 @@
#include "access/htup_details.h"
#include "access/table.h"
+#include "access/twophase.h"
#include "access/xact.h"
#include "catalog/catalog.h"
#include "catalog/dependency.h"
@@ -1143,7 +1144,8 @@ AlterSubscription(ParseState *pstate, AlterSubscriptionStmt *stmt,
{
supported_opts = (SUBOPT_SLOT_NAME |
SUBOPT_SYNCHRONOUS_COMMIT | SUBOPT_BINARY |
- SUBOPT_STREAMING | SUBOPT_DISABLE_ON_ERR |
+ SUBOPT_STREAMING | SUBOPT_TWOPHASE_COMMIT |
+ SUBOPT_DISABLE_ON_ERR |
SUBOPT_PASSWORD_REQUIRED |
SUBOPT_RUN_AS_OWNER | SUBOPT_FAILOVER |
SUBOPT_ORIGIN);
@@ -1151,6 +1153,53 @@ AlterSubscription(ParseState *pstate, AlterSubscriptionStmt *stmt,
parse_subscription_options(pstate, stmt->options,
supported_opts, &opts);
+ if (IsSet(opts.specified_opts, SUBOPT_TWOPHASE_COMMIT))
+ {
+ /*
+ * Do not allow changing the two_phase option if the
+ * subscription is enabled. This is because the two_phase
+ * option of the slot on the publisher cannot be modified
+ * if the slot is currently acquired by the apply worker.
+ */
+ if (form->subenabled)
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("cannot set %s for enabled subscription",
+ "two_phase")));
+
+ /*
+ * Stop all the subscription workers, just in case. Workers
+ * may still survive even if the subscription is disabled.
+ */
+ logicalrep_workers_stop(subid);
+
+ /*
+ * two_phase cannot be disabled if there are any
+ * uncommitted prepared transactions present.
+ */
+ if (!opts.twophase &&
+ form->subtwophasestate == LOGICALREP_TWOPHASE_STATE_ENABLED &&
+ LookupGXactBySubid(subid))
+ /* Add error message */
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("cannot disable two_phase when uncommitted prepared transactions present"),
+ errhint("Resolve these transactions and try again")));
+
+ /*
+ * The changed two_phase option of the slot can't be rolled
+ * back.
+ */
+ PreventInTransactionBlock(isTopLevel, "ALTER SUBSCRIPTION ... SET (two_phase)");
+
+ /* Change system catalog acoordingly */
+ values[Anum_pg_subscription_subtwophasestate - 1] =
+ CharGetDatum(opts.twophase ?
+ LOGICALREP_TWOPHASE_STATE_PENDING :
+ LOGICALREP_TWOPHASE_STATE_DISABLED);
+ replaces[Anum_pg_subscription_subtwophasestate - 1] = true;
+ }
+
if (IsSet(opts.specified_opts, SUBOPT_SLOT_NAME))
{
/*
@@ -1505,7 +1554,8 @@ AlterSubscription(ParseState *pstate, AlterSubscriptionStmt *stmt,
* doing the database operations we won't be able to rollback altered
* slot.
*/
- if (replaces[Anum_pg_subscription_subfailover - 1])
+ if (replaces[Anum_pg_subscription_subfailover - 1] ||
+ replaces[Anum_pg_subscription_subtwophasestate - 1])
{
bool must_use_password;
char *err;
@@ -1525,7 +1575,7 @@ AlterSubscription(ParseState *pstate, AlterSubscriptionStmt *stmt,
PG_TRY();
{
- walrcv_alter_slot(wrconn, sub->slotname, opts.failover);
+ walrcv_alter_slot(wrconn, sub->slotname, opts.failover, opts.twophase);
}
PG_FINALLY();
{
@@ -1562,7 +1612,6 @@ DropSubscription(DropSubscriptionStmt *stmt, bool isTopLevel)
char *subname;
char *conninfo;
char *slotname;
- List *subworkers;
ListCell *lc;
char originname[NAMEDATALEN];
char *err = NULL;
@@ -1672,16 +1721,7 @@ DropSubscription(DropSubscriptionStmt *stmt, bool isTopLevel)
* New workers won't be started because we hold an exclusive lock on the
* subscription till the end of the transaction.
*/
- LWLockAcquire(LogicalRepWorkerLock, LW_SHARED);
- subworkers = logicalrep_workers_find(subid, false);
- LWLockRelease(LogicalRepWorkerLock);
- foreach(lc, subworkers)
- {
- LogicalRepWorker *w = (LogicalRepWorker *) lfirst(lc);
-
- logicalrep_worker_stop(w->subid, w->relid);
- }
- list_free(subworkers);
+ logicalrep_workers_stop(subid);
/*
* Remove the no-longer-useful entry in the launcher's table of apply
diff --git a/src/backend/replication/libpqwalreceiver/libpqwalreceiver.c b/src/backend/replication/libpqwalreceiver/libpqwalreceiver.c
index 3c2b1bb496..998bbd517a 100644
--- a/src/backend/replication/libpqwalreceiver/libpqwalreceiver.c
+++ b/src/backend/replication/libpqwalreceiver/libpqwalreceiver.c
@@ -80,7 +80,7 @@ static char *libpqrcv_create_slot(WalReceiverConn *conn,
CRSSnapshotAction snapshot_action,
XLogRecPtr *lsn);
static void libpqrcv_alter_slot(WalReceiverConn *conn, const char *slotname,
- bool failover);
+ bool failover, bool two_phase);
static pid_t libpqrcv_get_backend_pid(WalReceiverConn *conn);
static WalRcvExecResult *libpqrcv_exec(WalReceiverConn *conn,
const char *query,
@@ -1121,15 +1121,16 @@ libpqrcv_create_slot(WalReceiverConn *conn, const char *slotname,
*/
static void
libpqrcv_alter_slot(WalReceiverConn *conn, const char *slotname,
- bool failover)
+ bool failover, bool two_phase)
{
StringInfoData cmd;
PGresult *res;
initStringInfo(&cmd);
- appendStringInfo(&cmd, "ALTER_REPLICATION_SLOT %s ( FAILOVER %s )",
+ appendStringInfo(&cmd, "ALTER_REPLICATION_SLOT %s ( FAILOVER %s, TWO_PHASE %s )",
quote_identifier(slotname),
- failover ? "true" : "false");
+ failover ? "true" : "false",
+ two_phase ? "true" : "false");
res = libpqrcv_PQexec(conn->streamConn, cmd.data);
pfree(cmd.data);
diff --git a/src/backend/replication/logical/launcher.c b/src/backend/replication/logical/launcher.c
index 66070e9131..548f6e0edb 100644
--- a/src/backend/replication/logical/launcher.c
+++ b/src/backend/replication/logical/launcher.c
@@ -623,6 +623,28 @@ logicalrep_worker_stop(Oid subid, Oid relid)
LWLockRelease(LogicalRepWorkerLock);
}
+/*
+ * Stop all the subscription workers.
+ */
+void
+logicalrep_workers_stop(Oid subid)
+{
+ List *subworkers;
+ ListCell *lc;
+
+ LWLockAcquire(LogicalRepWorkerLock, LW_SHARED);
+ /* XXX clarify the reason why not only running workers are listed. */
+ subworkers = logicalrep_workers_find(subid, false);
+ LWLockRelease(LogicalRepWorkerLock);
+ foreach(lc, subworkers)
+ {
+ LogicalRepWorker *w = (LogicalRepWorker *) lfirst(lc);
+
+ logicalrep_worker_stop(w->subid, w->relid);
+ }
+ list_free(subworkers);
+}
+
/*
* Stop the given logical replication parallel apply worker.
*
diff --git a/src/backend/replication/logical/worker.c b/src/backend/replication/logical/worker.c
index b5a80fe3e8..dcf656fd45 100644
--- a/src/backend/replication/logical/worker.c
+++ b/src/backend/replication/logical/worker.c
@@ -402,7 +402,6 @@ static void apply_handle_tuple_routing(ApplyExecutionData *edata,
CmdType operation);
/* Compute GID for two_phase transactions */
-static void TwoPhaseTransactionGid(Oid subid, TransactionId xid, char *gid, int szgid);
/* Functions for skipping changes */
static void maybe_start_skipping_changes(XLogRecPtr finish_lsn);
@@ -3911,7 +3910,7 @@ maybe_reread_subscription(void)
/* !slotname should never happen when enabled is true. */
Assert(newsub->slotname);
- /* two-phase should not be altered */
+ /* two-phase cannot be altered while the worker exists */
Assert(newsub->twophasestate == MySubscription->twophasestate);
/*
@@ -4396,24 +4395,6 @@ cleanup_subxact_info()
subxact_data.nsubxacts_max = 0;
}
-/*
- * Form the prepared transaction GID for two_phase transactions.
- *
- * Return the GID in the supplied buffer.
- */
-static void
-TwoPhaseTransactionGid(Oid subid, TransactionId xid, char *gid, int szgid)
-{
- Assert(subid != InvalidRepOriginId);
-
- if (!TransactionIdIsValid(xid))
- ereport(ERROR,
- (errcode(ERRCODE_PROTOCOL_VIOLATION),
- errmsg_internal("invalid two-phase transaction ID")));
-
- snprintf(gid, szgid, "pg_gid_%u_%u", subid, xid);
-}
-
/*
* Common function to run the apply loop with error handling. Disable the
* subscription, if necessary.
diff --git a/src/backend/replication/slot.c b/src/backend/replication/slot.c
index aa4ea387da..d0c8d5a4df 100644
--- a/src/backend/replication/slot.c
+++ b/src/backend/replication/slot.c
@@ -804,8 +804,10 @@ ReplicationSlotDrop(const char *name, bool nowait)
* Change the definition of the slot identified by the specified name.
*/
void
-ReplicationSlotAlter(const char *name, bool failover)
+ReplicationSlotAlter(const char *name, bool failover, bool two_phase)
{
+ bool update_slot = false;
+
Assert(MyReplicationSlot == NULL);
ReplicationSlotAcquire(name, false);
@@ -854,6 +856,20 @@ ReplicationSlotAlter(const char *name, bool failover)
MyReplicationSlot->data.failover = failover;
SpinLockRelease(&MyReplicationSlot->mutex);
+ update_slot = true;
+ }
+
+ if (MyReplicationSlot->data.two_phase != two_phase)
+ {
+ SpinLockAcquire(&MyReplicationSlot->mutex);
+ MyReplicationSlot->data.two_phase = two_phase;
+ SpinLockRelease(&MyReplicationSlot->mutex);
+
+ update_slot = true;
+ }
+
+ if (update_slot)
+ {
ReplicationSlotMarkDirty();
ReplicationSlotSave();
}
diff --git a/src/backend/replication/walsender.c b/src/backend/replication/walsender.c
index c623b07cf0..2e6ca35049 100644
--- a/src/backend/replication/walsender.c
+++ b/src/backend/replication/walsender.c
@@ -1411,9 +1411,11 @@ DropReplicationSlot(DropReplicationSlotCmd *cmd)
* Process extra options given to ALTER_REPLICATION_SLOT.
*/
static void
-ParseAlterReplSlotOptions(AlterReplicationSlotCmd *cmd, bool *failover)
+ParseAlterReplSlotOptions(AlterReplicationSlotCmd *cmd,
+ bool *failover, bool *two_phase)
{
bool failover_given = false;
+ bool two_phase_given = false;
/* Parse options */
foreach_ptr(DefElem, defel, cmd->options)
@@ -1427,6 +1429,15 @@ ParseAlterReplSlotOptions(AlterReplicationSlotCmd *cmd, bool *failover)
failover_given = true;
*failover = defGetBoolean(defel);
}
+ else if (strcmp(defel->defname, "two_phase") == 0)
+ {
+ if (two_phase_given)
+ ereport(ERROR,
+ (errcode(ERRCODE_SYNTAX_ERROR),
+ errmsg("conflicting or redundant options")));
+ two_phase_given = true;
+ *two_phase = defGetBoolean(defel);
+ }
else
elog(ERROR, "unrecognized option: %s", defel->defname);
}
@@ -1439,9 +1450,10 @@ static void
AlterReplicationSlot(AlterReplicationSlotCmd *cmd)
{
bool failover = false;
+ bool two_phase = false;
- ParseAlterReplSlotOptions(cmd, &failover);
- ReplicationSlotAlter(cmd->slotname, failover);
+ ParseAlterReplSlotOptions(cmd, &failover, &two_phase);
+ ReplicationSlotAlter(cmd->slotname, failover, two_phase);
}
/*
diff --git a/src/bin/psql/tab-complete.c b/src/bin/psql/tab-complete.c
index d453e224d9..891face1b6 100644
--- a/src/bin/psql/tab-complete.c
+++ b/src/bin/psql/tab-complete.c
@@ -1948,7 +1948,7 @@ psql_completion(const char *text, int start, int end)
else if (HeadMatches("ALTER", "SUBSCRIPTION", MatchAny) && TailMatches("SET", "("))
COMPLETE_WITH("binary", "disable_on_error", "failover", "origin",
"password_required", "run_as_owner", "slot_name",
- "streaming", "synchronous_commit");
+ "streaming", "synchronous_commit", "two_phase");
/* ALTER SUBSCRIPTION <name> SKIP ( */
else if (HeadMatches("ALTER", "SUBSCRIPTION", MatchAny) && TailMatches("SKIP", "("))
COMPLETE_WITH("lsn");
diff --git a/src/include/access/twophase.h b/src/include/access/twophase.h
index 56248c0006..d37e06fdee 100644
--- a/src/include/access/twophase.h
+++ b/src/include/access/twophase.h
@@ -62,4 +62,9 @@ extern void PrepareRedoRemove(TransactionId xid, bool giveWarning);
extern void restoreTwoPhaseData(void);
extern bool LookupGXact(const char *gid, XLogRecPtr prepare_end_lsn,
TimestampTz origin_prepare_timestamp);
+
+extern void TwoPhaseTransactionGid(Oid subid, TransactionId xid, char *gid,
+ int szgid);
+extern bool LookupGXactBySubid(Oid subid);
+
#endif /* TWOPHASE_H */
diff --git a/src/include/replication/slot.h b/src/include/replication/slot.h
index 1bc80960ef..014e216cf5 100644
--- a/src/include/replication/slot.h
+++ b/src/include/replication/slot.h
@@ -243,7 +243,8 @@ extern void ReplicationSlotCreate(const char *name, bool db_specific,
extern void ReplicationSlotPersist(void);
extern void ReplicationSlotDrop(const char *name, bool nowait);
extern void ReplicationSlotDropAcquired(void);
-extern void ReplicationSlotAlter(const char *name, bool failover);
+extern void ReplicationSlotAlter(const char *name, bool failover,
+ bool two_phase);
extern void ReplicationSlotAcquire(const char *name, bool nowait);
extern void ReplicationSlotRelease(void);
diff --git a/src/include/replication/walreceiver.h b/src/include/replication/walreceiver.h
index 12f71fa99b..31fa1257ec 100644
--- a/src/include/replication/walreceiver.h
+++ b/src/include/replication/walreceiver.h
@@ -372,12 +372,13 @@ typedef char *(*walrcv_create_slot_fn) (WalReceiverConn *conn,
/*
* walrcv_alter_slot_fn
*
- * Change the definition of a replication slot. Currently, it only supports
- * changing the failover property of the slot.
+ * Change the definition of a replication slot. Currently, it supports
+ * changing the failover and the two_phase property of the slot.
*/
typedef void (*walrcv_alter_slot_fn) (WalReceiverConn *conn,
const char *slotname,
- bool failover);
+ bool failover,
+ bool two_phase);
/*
* walrcv_get_backend_pid_fn
@@ -455,8 +456,8 @@ extern PGDLLIMPORT WalReceiverFunctionsType *WalReceiverFunctions;
WalReceiverFunctions->walrcv_send(conn, buffer, nbytes)
#define walrcv_create_slot(conn, slotname, temporary, two_phase, failover, snapshot_action, lsn) \
WalReceiverFunctions->walrcv_create_slot(conn, slotname, temporary, two_phase, failover, snapshot_action, lsn)
-#define walrcv_alter_slot(conn, slotname, failover) \
- WalReceiverFunctions->walrcv_alter_slot(conn, slotname, failover)
+#define walrcv_alter_slot(conn, slotname, failover, two_phase) \
+ WalReceiverFunctions->walrcv_alter_slot(conn, slotname, failover, two_phase)
#define walrcv_get_backend_pid(conn) \
WalReceiverFunctions->walrcv_get_backend_pid(conn)
#define walrcv_exec(conn, exec, nRetTypes, retTypes) \
diff --git a/src/include/replication/worker_internal.h b/src/include/replication/worker_internal.h
index 515aefd519..d5428263c1 100644
--- a/src/include/replication/worker_internal.h
+++ b/src/include/replication/worker_internal.h
@@ -246,6 +246,7 @@ extern bool logicalrep_worker_launch(LogicalRepWorkerType wtype,
Oid userid, Oid relid,
dsm_handle subworker_dsm);
extern void logicalrep_worker_stop(Oid subid, Oid relid);
+extern void logicalrep_workers_stop(Oid subid);
extern void logicalrep_pa_worker_stop(ParallelApplyWorkerInfo *winfo);
extern void logicalrep_worker_wakeup(Oid subid, Oid relid);
extern void logicalrep_worker_wakeup_ptr(LogicalRepWorker *worker);
diff --git a/src/test/regress/expected/subscription.out b/src/test/regress/expected/subscription.out
index 0f2a25cdc1..51fa4b9690 100644
--- a/src/test/regress/expected/subscription.out
+++ b/src/test/regress/expected/subscription.out
@@ -377,10 +377,7 @@ HINT: To initiate replication, you must manually create the replication slot, e
regress_testsub | regress_subscription_user | f | {testpub} | f | off | p | f | any | t | f | f | off | dbname=regress_doesnotexist | 0/0
(1 row)
---fail - alter of two_phase option not supported.
-ALTER SUBSCRIPTION regress_testsub SET (two_phase = false);
-ERROR: unrecognized subscription parameter: "two_phase"
--- but can alter streaming when two_phase enabled
+-- We can alter streaming when two_phase enabled
ALTER SUBSCRIPTION regress_testsub SET (streaming = true);
\dRs+
List of subscriptions
diff --git a/src/test/regress/sql/subscription.sql b/src/test/regress/sql/subscription.sql
index 3e5ba4cb8c..a3886d79ca 100644
--- a/src/test/regress/sql/subscription.sql
+++ b/src/test/regress/sql/subscription.sql
@@ -256,10 +256,7 @@ CREATE SUBSCRIPTION regress_testsub CONNECTION 'dbname=regress_doesnotexist' PUB
CREATE SUBSCRIPTION regress_testsub CONNECTION 'dbname=regress_doesnotexist' PUBLICATION testpub WITH (connect = false, two_phase = true);
\dRs+
---fail - alter of two_phase option not supported.
-ALTER SUBSCRIPTION regress_testsub SET (two_phase = false);
-
--- but can alter streaming when two_phase enabled
+-- We can alter streaming when two_phase enabled
ALTER SUBSCRIPTION regress_testsub SET (streaming = true);
\dRs+
diff --git a/src/test/subscription/t/021_twophase.pl b/src/test/subscription/t/021_twophase.pl
index 9437cd4c3b..72df258000 100644
--- a/src/test/subscription/t/021_twophase.pl
+++ b/src/test/subscription/t/021_twophase.pl
@@ -367,6 +367,75 @@ $result =
$node_subscriber->safe_psql('postgres', "SELECT count(*) FROM tab_copy;");
is($result, qq(2), 'replicated data in subscriber table');
+# Clean up
+$node_subscriber->safe_psql('postgres', "DROP SUBSCRIPTION tap_sub");
+
+###############################
+# Disable the subscription and alter it to two_phase = false,
+# then verify that the altered subscription reflects the two_phase option.
+###############################
+
+# Alter subscription two_phase to false
+$node_subscriber->safe_psql('postgres',
+ "ALTER SUBSCRIPTION tap_sub_copy DISABLE");
+$node_subscriber->safe_psql('postgres',
+ "ALTER SUBSCRIPTION tap_sub_copy SET (two_phase = false)");
+$node_subscriber->safe_psql('postgres',
+ "ALTER SUBSCRIPTION tap_sub_copy ENABLE");
+
+# Wait for subscription startup
+$node_subscriber->wait_for_subscription_sync($node_publisher, $appname_copy);
+
+# Make sure that the two-phase is disabled on the subscriber
+$result = $node_subscriber->safe_psql('postgres',
+ "SELECT subtwophasestate FROM pg_subscription WHERE subname = 'tap_sub_copy';"
+);
+is($result, qq(d), 'two-phase should be disabled');
+
+# Now do a prepare on the publisher and make sure that it is not replicated.
+$node_publisher->safe_psql(
+ 'postgres', qq{
+ BEGIN;
+ INSERT INTO tab_copy VALUES (100);
+ PREPARE TRANSACTION 'newgid';
+ });
+
+# Wait for the subscriber to catchup
+$node_publisher->wait_for_catchup($appname_copy);
+
+# Make sure there are no prepared transactions on the subscriber
+$result = $node_subscriber->safe_psql('postgres',
+ "SELECT count(*) FROM pg_prepared_xacts;");
+is($result, qq(0), 'should be no prepared transactions on subscriber');
+
+# Now commit the insert and verify that it IS replicated
+$node_publisher->safe_psql('postgres', "COMMIT PREPARED 'newgid';");
+
+# Wait for the subscriber to catchup
+$node_publisher->wait_for_catchup($appname_copy);
+
+# Make sure that the committed transaction is replicated.
+$result =
+ $node_subscriber->safe_psql('postgres', "SELECT count(*) FROM tab_copy;");
+is($result, qq(3), 'replicated data in subscriber table');
+
+# Alter subscription two_phase to true
+$node_subscriber->safe_psql('postgres',
+ "ALTER SUBSCRIPTION tap_sub_copy DISABLE");
+$node_subscriber->safe_psql('postgres',
+ "ALTER SUBSCRIPTION tap_sub_copy SET (two_phase = true)");
+$node_subscriber->safe_psql('postgres',
+ "ALTER SUBSCRIPTION tap_sub_copy ENABLE");
+
+# Wait for subscription startup
+$node_subscriber->wait_for_subscription_sync($node_publisher, $appname_copy);
+
+# Make sure that the two-phase is enabled on the subscriber
+$result = $node_subscriber->safe_psql('postgres',
+ "SELECT subtwophasestate FROM pg_subscription WHERE subname = 'tap_sub_copy';"
+);
+is($result, qq(e), 'two-phase should be enabled');
+
$node_subscriber->safe_psql('postgres', "DROP SUBSCRIPTION tap_sub_copy;");
$node_publisher->safe_psql('postgres', "DROP PUBLICATION tap_pub_copy;");
@@ -374,8 +443,6 @@ $node_publisher->safe_psql('postgres', "DROP PUBLICATION tap_pub_copy;");
# check all the cleanup
###############################
-$node_subscriber->safe_psql('postgres', "DROP SUBSCRIPTION tap_sub");
-
$result = $node_subscriber->safe_psql('postgres',
"SELECT count(*) FROM pg_subscription");
is($result, qq(0), 'check subscription was dropped on subscriber');
--
2.43.0
[application/octet-stream] v7-0002-Alter-slot-option-two_phase-only-when-altering-tr.patch (8.7K, ../../OSBPR01MB2552521ABDBC2F995FBACDF7F5E52@OSBPR01MB2552.jpnprd01.prod.outlook.com/3-v7-0002-Alter-slot-option-two_phase-only-when-altering-tr.patch)
download | inline diff:
From 1f65aaeacb63502cf6f2eb0d6f3889037a1bff9f Mon Sep 17 00:00:00 2001
From: Hayato Kuroda <[email protected]>
Date: Wed, 17 Apr 2024 06:18:23 +0000
Subject: [PATCH v7 2/4] Alter slot option two_phase only when altering true to
false
---
doc/src/sgml/ref/alter_subscription.sgml | 2 +-
src/backend/commands/subscriptioncmds.c | 23 +++++-
.../libpqwalreceiver/libpqwalreceiver.c | 21 ++++--
src/include/replication/walreceiver.h | 5 +-
src/test/subscription/meson.build | 1 +
src/test/subscription/t/099_twophase_added.pl | 72 +++++++++++++++++++
6 files changed, 113 insertions(+), 11 deletions(-)
create mode 100644 src/test/subscription/t/099_twophase_added.pl
diff --git a/doc/src/sgml/ref/alter_subscription.sgml b/doc/src/sgml/ref/alter_subscription.sgml
index 88e9a72147..0c2894a94e 100644
--- a/doc/src/sgml/ref/alter_subscription.sgml
+++ b/doc/src/sgml/ref/alter_subscription.sgml
@@ -70,7 +70,7 @@ ALTER SUBSCRIPTION <replaceable class="parameter">name</replaceable> RENAME TO <
<command>ALTER SUBSCRIPTION ... {SET|ADD|DROP} PUBLICATION ...</command>
with <literal>refresh</literal> option as <literal>true</literal>,
<command>ALTER SUBSCRIPTION ... SET (failover = on|off)</command> and
- <command>ALTER SUBSCRIPTION ... SET (two_phase = on|off)</command>
+ <command>ALTER SUBSCRIPTION ... SET (two_phase = off)</command>
cannot be executed inside a transaction block.
These commands also cannot be executed when the subscription has
diff --git a/src/backend/commands/subscriptioncmds.c b/src/backend/commands/subscriptioncmds.c
index 1a2f0c1e64..71b058b385 100644
--- a/src/backend/commands/subscriptioncmds.c
+++ b/src/backend/commands/subscriptioncmds.c
@@ -1190,7 +1190,9 @@ AlterSubscription(ParseState *pstate, AlterSubscriptionStmt *stmt,
* The changed two_phase option of the slot can't be rolled
* back.
*/
- PreventInTransactionBlock(isTopLevel, "ALTER SUBSCRIPTION ... SET (two_phase)");
+ if (!opts.twophase)
+ PreventInTransactionBlock(isTopLevel,
+ "ALTER SUBSCRIPTION ... SET (two_phase = off)");
/* Change system catalog acoordingly */
values[Anum_pg_subscription_subtwophasestate - 1] =
@@ -1560,6 +1562,8 @@ AlterSubscription(ParseState *pstate, AlterSubscriptionStmt *stmt,
bool must_use_password;
char *err;
WalReceiverConn *wrconn;
+ bool failover_needs_to_be_updated;
+ bool two_phase_needs_to_be_updated;
/* Load the library providing us libpq calls. */
load_file("libpqwalreceiver", false);
@@ -1573,9 +1577,24 @@ AlterSubscription(ParseState *pstate, AlterSubscriptionStmt *stmt,
(errcode(ERRCODE_CONNECTION_FAILURE),
errmsg("could not connect to the publisher: %s", err)));
+ /*
+ * Consider which slot option must be altered.
+ *
+ * We must alter the failover option whenever subfailover is updated.
+ * Two_phase, however, is altered only when changing true to false.
+ */
+ failover_needs_to_be_updated =
+ replaces[Anum_pg_subscription_subfailover - 1];
+ two_phase_needs_to_be_updated =
+ (replaces[Anum_pg_subscription_subtwophasestate - 1] &&
+ !opts.twophase);
+
PG_TRY();
{
- walrcv_alter_slot(wrconn, sub->slotname, opts.failover, opts.twophase);
+ if (two_phase_needs_to_be_updated || failover_needs_to_be_updated)
+ walrcv_alter_slot(wrconn, sub->slotname,
+ failover_needs_to_be_updated ? &opts.failover : NULL,
+ two_phase_needs_to_be_updated ? &opts.twophase : NULL);
}
PG_FINALLY();
{
diff --git a/src/backend/replication/libpqwalreceiver/libpqwalreceiver.c b/src/backend/replication/libpqwalreceiver/libpqwalreceiver.c
index 998bbd517a..c383767096 100644
--- a/src/backend/replication/libpqwalreceiver/libpqwalreceiver.c
+++ b/src/backend/replication/libpqwalreceiver/libpqwalreceiver.c
@@ -80,7 +80,7 @@ static char *libpqrcv_create_slot(WalReceiverConn *conn,
CRSSnapshotAction snapshot_action,
XLogRecPtr *lsn);
static void libpqrcv_alter_slot(WalReceiverConn *conn, const char *slotname,
- bool failover, bool two_phase);
+ const bool *failover, const bool *two_phase);
static pid_t libpqrcv_get_backend_pid(WalReceiverConn *conn);
static WalRcvExecResult *libpqrcv_exec(WalReceiverConn *conn,
const char *query,
@@ -1121,16 +1121,25 @@ libpqrcv_create_slot(WalReceiverConn *conn, const char *slotname,
*/
static void
libpqrcv_alter_slot(WalReceiverConn *conn, const char *slotname,
- bool failover, bool two_phase)
+ const bool *failover, const bool *two_phase)
{
StringInfoData cmd;
PGresult *res;
initStringInfo(&cmd);
- appendStringInfo(&cmd, "ALTER_REPLICATION_SLOT %s ( FAILOVER %s, TWO_PHASE %s )",
- quote_identifier(slotname),
- failover ? "true" : "false",
- two_phase ? "true" : "false");
+ appendStringInfo(&cmd, "ALTER_REPLICATION_SLOT %s ( ",
+ quote_identifier(slotname));
+
+ if (failover)
+ appendStringInfo(&cmd, "FAILOVER %s ",
+ (*failover) ? "true" : "false");
+
+ if (two_phase)
+ appendStringInfo(&cmd, "TWO_PHASE %s%s ",
+ (*two_phase) ? "true" : "false",
+ failover ? ", " : "");
+
+ appendStringInfoString(&cmd, ");");
res = libpqrcv_PQexec(conn->streamConn, cmd.data);
pfree(cmd.data);
diff --git a/src/include/replication/walreceiver.h b/src/include/replication/walreceiver.h
index 31fa1257ec..7ffa5a58b3 100644
--- a/src/include/replication/walreceiver.h
+++ b/src/include/replication/walreceiver.h
@@ -377,8 +377,9 @@ typedef char *(*walrcv_create_slot_fn) (WalReceiverConn *conn,
*/
typedef void (*walrcv_alter_slot_fn) (WalReceiverConn *conn,
const char *slotname,
- bool failover,
- bool two_phase);
+ const bool *failover,
+ const bool *two_phase);
+
/*
* walrcv_get_backend_pid_fn
diff --git a/src/test/subscription/meson.build b/src/test/subscription/meson.build
index c591cd7d61..b4bd522c3d 100644
--- a/src/test/subscription/meson.build
+++ b/src/test/subscription/meson.build
@@ -40,6 +40,7 @@ tests += {
't/031_column_list.pl',
't/032_subscribe_use_index.pl',
't/033_run_as_table_owner.pl',
+ 't/099_twophase_added.pl',
't/100_bugs.pl',
],
},
diff --git a/src/test/subscription/t/099_twophase_added.pl b/src/test/subscription/t/099_twophase_added.pl
new file mode 100644
index 0000000000..c13a37675a
--- /dev/null
+++ b/src/test/subscription/t/099_twophase_added.pl
@@ -0,0 +1,72 @@
+# Copyright (c) 2021-2024, PostgreSQL Global Development Group
+
+# Additional tests for altering two_phase option
+use strict;
+use warnings FATAL => 'all';
+use PostgreSQL::Test::Cluster;
+use PostgreSQL::Test::Utils;
+use Test::More;
+
+# Initialize publisher node
+my $node_publisher = PostgreSQL::Test::Cluster->new('publisher');
+$node_publisher->init(allows_streaming => 'logical');
+$node_publisher->append_conf('postgresql.conf',
+ qq(max_prepared_transactions = 10));
+$node_publisher->start;
+
+# Create subscriber node
+my $node_subscriber = PostgreSQL::Test::Cluster->new('subscriber');
+$node_subscriber->init;
+$node_subscriber->append_conf('postgresql.conf',
+ qq(max_prepared_transactions = 10));
+$node_subscriber->start;
+
+# Define pre-existing tables on both nodes
+$node_publisher->safe_psql('postgres',
+ "CREATE TABLE tab_full (a int PRIMARY KEY);");
+$node_subscriber->safe_psql('postgres',
+ "CREATE TABLE tab_full (a int PRIMARY KEY)");
+
+# Setup logical replication, with two_phase = off
+my $publisher_connstr = $node_publisher->connstr . ' dbname=postgres';
+$node_publisher->safe_psql('postgres',
+ "CREATE PUBLICATION pub FOR ALL TABLES");
+
+$node_subscriber->safe_psql(
+ 'postgres', "
+ CREATE SUBSCRIPTION sub
+ CONNECTION '$publisher_connstr' PUBLICATION pub
+ WITH (two_phase = off, copy_data = off)");
+
+######
+# Check the case that prepared transactions exist on publisher node
+######
+
+$node_publisher->safe_psql(
+ 'postgres', "
+ BEGIN;
+ INSERT INTO tab_full VALUES (generate_series(1, 5));
+ PREPARE TRANSACTION 'test_prepared_tab_full';");
+
+$node_publisher->wait_for_catchup('sub');
+
+my $result = $node_subscriber->safe_psql('postgres',
+ "SELECT count(*) FROM pg_prepared_xacts;");
+is($result, q(0), "transaction is not prepared on subscriber");
+
+$node_subscriber->safe_psql(
+ 'postgres', "
+ ALTER SUBSCRIPTION sub DISABLE;
+ ALTER SUBSCRIPTION sub SET (two_phase = on);
+ ALTER SUBSCRIPTION sub ENABLE;");
+
+$node_publisher->safe_psql( 'postgres',
+ "COMMIT PREPARED 'test_prepared_tab_full';");
+$node_publisher->wait_for_catchup('sub');
+
+$result = $node_subscriber->safe_psql('postgres',
+ "SELECT count(*) FROM tab_full;");
+is($result, q(5),
+ "prepared transactions done before altering can be replicated");
+
+done_testing();
--
2.43.0
[application/octet-stream] v7-0003-Abort-prepared-transactions-while-altering-two_ph.patch (7.4K, ../../OSBPR01MB2552521ABDBC2F995FBACDF7F5E52@OSBPR01MB2552.jpnprd01.prod.outlook.com/4-v7-0003-Abort-prepared-transactions-while-altering-two_ph.patch)
download | inline diff:
From c23330158b9e7407922d766d4c7ea6113eda14b2 Mon Sep 17 00:00:00 2001
From: Hayato Kuroda <[email protected]>
Date: Mon, 8 Apr 2024 12:39:12 +0000
Subject: [PATCH v7 3/4] Abort prepared transactions while altering two_phase
to false
---
doc/src/sgml/ref/alter_subscription.sgml | 9 ++++-
src/backend/access/transam/twophase.c | 17 ++++----
src/backend/commands/subscriptioncmds.c | 39 ++++++++++++-------
src/include/access/twophase.h | 3 +-
src/test/subscription/t/099_twophase_added.pl | 35 +++++++++++++++++
5 files changed, 75 insertions(+), 28 deletions(-)
diff --git a/doc/src/sgml/ref/alter_subscription.sgml b/doc/src/sgml/ref/alter_subscription.sgml
index 0c2894a94e..848e4af649 100644
--- a/doc/src/sgml/ref/alter_subscription.sgml
+++ b/doc/src/sgml/ref/alter_subscription.sgml
@@ -233,8 +233,6 @@ ALTER SUBSCRIPTION <replaceable class="parameter">name</replaceable> RENAME TO <
<link linkend="sql-createsubscription-params-with-failover"><literal>failover</literal></link>, and
<link linkend="sql-createsubscription-params-with-two-phase"><literal>two_phase</literal></link>.
Only a superuser can set <literal>password_required = false</literal>.
- The <literal>two_phase</literal> parameter can only be altered when the
- subscription is disabled.
</para>
<para>
@@ -256,6 +254,13 @@ ALTER SUBSCRIPTION <replaceable class="parameter">name</replaceable> RENAME TO <
<link linkend="sql-createsubscription-params-with-failover"><literal>failover</literal></link>
option is enabled.
</para>
+
+ <para>
+ The <literal>two_phase</literal> parameter can only be altered when the
+ subscription is disabled. When altering the parameter from <literal>true</literal>
+ to <literal>false</literal>, the backend process checks prepared
+ transactions done by the logical replication worker and aborts them.
+ </para>
</listitem>
</varlistentry>
diff --git a/src/backend/access/transam/twophase.c b/src/backend/access/transam/twophase.c
index a67a8c48aa..e0cc0e9b21 100644
--- a/src/backend/access/transam/twophase.c
+++ b/src/backend/access/transam/twophase.c
@@ -2719,13 +2719,13 @@ IsTwoPhaseTransactionGidForSubid(Oid subid, char *gid)
}
/*
- * LookupGXactBySubid
- * Check if the prepared transaction done by apply worker exists.
+ * GetGidListBySubid
+ * Get a list of GIDs which is PREPARE'd by the given subscription.
*/
-bool
-LookupGXactBySubid(Oid subid)
+List *
+GetGidListBySubid(Oid subid)
{
- bool found = false;
+ List *list = NIL;
LWLockAcquire(TwoPhaseStateLock, LW_SHARED);
for (int i = 0; i < TwoPhaseState->numPrepXacts; i++)
@@ -2735,11 +2735,8 @@ LookupGXactBySubid(Oid subid)
/* Ignore not-yet-valid GIDs. */
if (gxact->valid &&
IsTwoPhaseTransactionGidForSubid(subid, gxact->gid))
- {
- found = true;
- break;
- }
+ list = lappend(list, pstrdup(gxact->gid));
}
LWLockRelease(TwoPhaseStateLock);
- return found;
+ return list;
}
diff --git a/src/backend/commands/subscriptioncmds.c b/src/backend/commands/subscriptioncmds.c
index 71b058b385..27be6299e0 100644
--- a/src/backend/commands/subscriptioncmds.c
+++ b/src/backend/commands/subscriptioncmds.c
@@ -1155,6 +1155,8 @@ AlterSubscription(ParseState *pstate, AlterSubscriptionStmt *stmt,
if (IsSet(opts.specified_opts, SUBOPT_TWOPHASE_COMMIT))
{
+ List *prepared_xacts = NIL;
+
/*
* Do not allow changing the two_phase option if the
* subscription is enabled. This is because the two_phase
@@ -1174,26 +1176,33 @@ AlterSubscription(ParseState *pstate, AlterSubscriptionStmt *stmt,
logicalrep_workers_stop(subid);
/*
- * two_phase cannot be disabled if there are any
- * uncommitted prepared transactions present.
- */
- if (!opts.twophase &&
- form->subtwophasestate == LOGICALREP_TWOPHASE_STATE_ENABLED &&
- LookupGXactBySubid(subid))
- /* Add error message */
- ereport(ERROR,
- (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
- errmsg("cannot disable two_phase when uncommitted prepared transactions present"),
- errhint("Resolve these transactions and try again")));
-
- /*
- * The changed two_phase option of the slot can't be rolled
- * back.
+ * If two_phase was enabled, there is a possibility the
+ * transactions has already been PREPARE'd. They must be
+ * checked and rolled back.
*/
if (!opts.twophase)
+ {
+ /*
+ * The changed two_phase option (true->false) of the
+ * slot can't be rolled back.
+ */
PreventInTransactionBlock(isTopLevel,
"ALTER SUBSCRIPTION ... SET (two_phase = off)");
+ if (sub->twophasestate == LOGICALREP_TWOPHASE_STATE_ENABLED &&
+ (prepared_xacts = GetGidListBySubid(subid)) != NIL)
+ {
+ ListCell *cell;
+
+ /* Abort all listed transactions */
+ foreach(cell, prepared_xacts)
+ FinishPreparedTransaction((char *) lfirst(cell),
+ false);
+
+ list_free(prepared_xacts);
+ }
+ }
+
/* Change system catalog acoordingly */
values[Anum_pg_subscription_subtwophasestate - 1] =
CharGetDatum(opts.twophase ?
diff --git a/src/include/access/twophase.h b/src/include/access/twophase.h
index d37e06fdee..f7a5cf0c12 100644
--- a/src/include/access/twophase.h
+++ b/src/include/access/twophase.h
@@ -18,6 +18,7 @@
#include "access/xlogdefs.h"
#include "datatype/timestamp.h"
#include "storage/lock.h"
+#include "nodes/pg_list.h"
/*
* GlobalTransactionData is defined in twophase.c; other places have no
@@ -65,6 +66,6 @@ extern bool LookupGXact(const char *gid, XLogRecPtr prepare_end_lsn,
extern void TwoPhaseTransactionGid(Oid subid, TransactionId xid, char *gid,
int szgid);
-extern bool LookupGXactBySubid(Oid subid);
+extern List *GetGidListBySubid(Oid subid);
#endif /* TWOPHASE_H */
diff --git a/src/test/subscription/t/099_twophase_added.pl b/src/test/subscription/t/099_twophase_added.pl
index c13a37675a..a8135b671c 100644
--- a/src/test/subscription/t/099_twophase_added.pl
+++ b/src/test/subscription/t/099_twophase_added.pl
@@ -69,4 +69,39 @@ $result = $node_subscriber->safe_psql('postgres',
is($result, q(5),
"prepared transactions done before altering can be replicated");
+######
+# Check the case that prepared transactions exist on subscriber node
+######
+
+$node_publisher->safe_psql(
+ 'postgres', "
+ BEGIN;
+ INSERT INTO tab_full VALUES (generate_series(6, 10));
+ PREPARE TRANSACTION 'test_prepared_tab_full';");
+
+$node_publisher->wait_for_catchup('sub');
+
+$result = $node_subscriber->safe_psql('postgres',
+ "SELECT count(*) FROM pg_prepared_xacts;");
+is($result, q(1), "transaction has been prepared on subscriber");
+
+$node_subscriber->safe_psql(
+ 'postgres', "
+ ALTER SUBSCRIPTION sub DISABLE;
+ ALTER SUBSCRIPTION sub SET (two_phase = off);
+ ALTER SUBSCRIPTION sub ENABLE;");
+
+$result = $node_subscriber->safe_psql('postgres',
+ "SELECT count(*) FROM pg_prepared_xacts;");
+is($result, q(0), "prepared transaction done by worker is aborted");
+
+$node_publisher->safe_psql( 'postgres',
+ "COMMIT PREPARED 'test_prepared_tab_full';");
+$node_publisher->wait_for_catchup('sub');
+
+$result = $node_subscriber->safe_psql('postgres',
+ "SELECT count(10) FROM tab_full;");
+is($result, q(10),
+ "prepared transactions on publisher can be replicated");
+
done_testing();
--
2.43.0
[application/octet-stream] v7-0004-Add-force_alter-option.patch (8.2K, ../../OSBPR01MB2552521ABDBC2F995FBACDF7F5E52@OSBPR01MB2552.jpnprd01.prod.outlook.com/5-v7-0004-Add-force_alter-option.patch)
download | inline diff:
From 71feafb120da3a499f15427d5e9c4f41800cf6c6 Mon Sep 17 00:00:00 2001
From: Hayato Kuroda <[email protected]>
Date: Fri, 19 Apr 2024 11:03:19 +0000
Subject: [PATCH v7 4/4] Add force_alter option
---
doc/src/sgml/ref/alter_subscription.sgml | 9 +++--
src/backend/commands/subscriptioncmds.c | 33 ++++++++++++++++++-
src/test/regress/expected/subscription.out | 3 ++
src/test/regress/sql/subscription.sql | 3 ++
src/test/subscription/t/099_twophase_added.pl | 23 ++++++++++---
5 files changed, 62 insertions(+), 9 deletions(-)
diff --git a/doc/src/sgml/ref/alter_subscription.sgml b/doc/src/sgml/ref/alter_subscription.sgml
index 848e4af649..bbfaa72229 100644
--- a/doc/src/sgml/ref/alter_subscription.sgml
+++ b/doc/src/sgml/ref/alter_subscription.sgml
@@ -257,9 +257,12 @@ ALTER SUBSCRIPTION <replaceable class="parameter">name</replaceable> RENAME TO <
<para>
The <literal>two_phase</literal> parameter can only be altered when the
- subscription is disabled. When altering the parameter from <literal>true</literal>
- to <literal>false</literal>, the backend process checks prepared
- transactions done by the logical replication worker and aborts them.
+ subscription is disabled. Altering the parameter from <literal>true</literal>
+ to <literal>false</literal> will be failed when there are prepared
+ transactions done by the logical replication worker. If you want to alter
+ the parameter forcibly in this case, <literal>force_alter</literal>
+ option must be set to <literal>true</literal> at the same time. If
+ specified, the backend process aborts prepared transactions.
</para>
</listitem>
</varlistentry>
diff --git a/src/backend/commands/subscriptioncmds.c b/src/backend/commands/subscriptioncmds.c
index 27be6299e0..512357f9a4 100644
--- a/src/backend/commands/subscriptioncmds.c
+++ b/src/backend/commands/subscriptioncmds.c
@@ -73,6 +73,7 @@
#define SUBOPT_FAILOVER 0x00002000
#define SUBOPT_LSN 0x00004000
#define SUBOPT_ORIGIN 0x00008000
+#define SUBOPT_FORCE_ALTER 0x00010000
/* check if the 'val' has 'bits' set */
#define IsSet(val, bits) (((val) & (bits)) == (bits))
@@ -100,6 +101,7 @@ typedef struct SubOpts
bool failover;
char *origin;
XLogRecPtr lsn;
+ bool twophase_force;
} SubOpts;
static List *fetch_table_list(WalReceiverConn *wrconn, List *publications);
@@ -162,6 +164,8 @@ parse_subscription_options(ParseState *pstate, List *stmt_options,
opts->failover = false;
if (IsSet(supported_opts, SUBOPT_ORIGIN))
opts->origin = pstrdup(LOGICALREP_ORIGIN_ANY);
+ if (IsSet(supported_opts, SUBOPT_FORCE_ALTER))
+ opts->twophase_force = false;
/* Parse options */
foreach(lc, stmt_options)
@@ -367,6 +371,15 @@ parse_subscription_options(ParseState *pstate, List *stmt_options,
opts->specified_opts |= SUBOPT_LSN;
opts->lsn = lsn;
}
+ else if (IsSet(supported_opts, SUBOPT_FORCE_ALTER) &&
+ strcmp(defel->defname, "force_alter") == 0)
+ {
+ if (IsSet(opts->specified_opts, SUBOPT_FORCE_ALTER))
+ errorConflictingDefElem(defel, pstate);
+
+ opts->specified_opts |= SUBOPT_FORCE_ALTER;
+ opts->twophase_force = defGetBoolean(defel);
+ }
else
ereport(ERROR,
(errcode(ERRCODE_SYNTAX_ERROR),
@@ -1148,7 +1161,7 @@ AlterSubscription(ParseState *pstate, AlterSubscriptionStmt *stmt,
SUBOPT_DISABLE_ON_ERR |
SUBOPT_PASSWORD_REQUIRED |
SUBOPT_RUN_AS_OWNER | SUBOPT_FAILOVER |
- SUBOPT_ORIGIN);
+ SUBOPT_ORIGIN | SUBOPT_FORCE_ALTER);
parse_subscription_options(pstate, stmt->options,
supported_opts, &opts);
@@ -1194,6 +1207,16 @@ AlterSubscription(ParseState *pstate, AlterSubscriptionStmt *stmt,
{
ListCell *cell;
+ /*
+ * Abort prepared transactions if force option is also
+ * specified. Otherwise raise an ERROR.
+ */
+ if (!opts.twophase_force)
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("cannot alter %s when there are prepared transactions",
+ "two_phase = false")));
+
/* Abort all listed transactions */
foreach(cell, prepared_xacts)
FinishPreparedTransaction((char *) lfirst(cell),
@@ -1323,6 +1346,14 @@ AlterSubscription(ParseState *pstate, AlterSubscriptionStmt *stmt,
replaces[Anum_pg_subscription_suborigin - 1] = true;
}
+ /* force_alter cannot be used standalone */
+ if (IsSet(opts.specified_opts, SUBOPT_FORCE_ALTER) &&
+ !IsSet(opts.specified_opts, SUBOPT_TWOPHASE_COMMIT))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("%s must be specified with %s",
+ "force_alter", "two_phase")));
+
update_tuple = true;
break;
}
diff --git a/src/test/regress/expected/subscription.out b/src/test/regress/expected/subscription.out
index 51fa4b9690..f607045b28 100644
--- a/src/test/regress/expected/subscription.out
+++ b/src/test/regress/expected/subscription.out
@@ -370,6 +370,9 @@ ERROR: two_phase requires a Boolean value
CREATE SUBSCRIPTION regress_testsub CONNECTION 'dbname=regress_doesnotexist' PUBLICATION testpub WITH (connect = false, two_phase = true);
WARNING: subscription was created, but is not connected
HINT: To initiate replication, you must manually create the replication slot, enable the subscription, and refresh the subscription.
+-- fail - force_alter cannot be set alone
+ALTER SUBSCRIPTION regress_testsub SET (force_alter = true);
+ERROR: force_alter must be specified with two_phase
\dRs+
List of subscriptions
Name | Owner | Enabled | Publication | Binary | Streaming | Two-phase commit | Disable on error | Origin | Password required | Run as owner? | Failover | Synchronous commit | Conninfo | Skip LSN
diff --git a/src/test/regress/sql/subscription.sql b/src/test/regress/sql/subscription.sql
index a3886d79ca..80ab4dd9bc 100644
--- a/src/test/regress/sql/subscription.sql
+++ b/src/test/regress/sql/subscription.sql
@@ -255,6 +255,9 @@ CREATE SUBSCRIPTION regress_testsub CONNECTION 'dbname=regress_doesnotexist' PUB
-- now it works
CREATE SUBSCRIPTION regress_testsub CONNECTION 'dbname=regress_doesnotexist' PUBLICATION testpub WITH (connect = false, two_phase = true);
+-- fail - force_alter cannot be set alone
+ALTER SUBSCRIPTION regress_testsub SET (force_alter = true);
+
\dRs+
-- We can alter streaming when two_phase enabled
ALTER SUBSCRIPTION regress_testsub SET (streaming = true);
diff --git a/src/test/subscription/t/099_twophase_added.pl b/src/test/subscription/t/099_twophase_added.pl
index a8135b671c..7c73a58f2a 100644
--- a/src/test/subscription/t/099_twophase_added.pl
+++ b/src/test/subscription/t/099_twophase_added.pl
@@ -85,16 +85,29 @@ $result = $node_subscriber->safe_psql('postgres',
"SELECT count(*) FROM pg_prepared_xacts;");
is($result, q(1), "transaction has been prepared on subscriber");
-$node_subscriber->safe_psql(
- 'postgres', "
- ALTER SUBSCRIPTION sub DISABLE;
- ALTER SUBSCRIPTION sub SET (two_phase = off);
- ALTER SUBSCRIPTION sub ENABLE;");
+$node_subscriber->safe_psql('postgres', "ALTER SUBSCRIPTION sub DISABLE;");
+
+my $stdout;
+my $stderr;
+
+($result, $stdout, $stderr) = $node_subscriber->psql(
+ 'postgres', "ALTER SUBSCRIPTION sub SET (two_phase = off);");
+ok($stderr =~ /cannot alter two_phase = false when there are prepared transactions/,
+ 'ALTER SUBSCRIPTION failed');
+
+$result = $node_subscriber->safe_psql('postgres',
+ "SELECT count(*) FROM pg_prepared_xacts;");
+is($result, q(1), "prepared transaction still exits");
+
+$node_subscriber->safe_psql('postgres',
+ "ALTER SUBSCRIPTION sub SET (two_phase = off, force_alter = on);");
$result = $node_subscriber->safe_psql('postgres',
"SELECT count(*) FROM pg_prepared_xacts;");
is($result, q(0), "prepared transaction done by worker is aborted");
+$node_subscriber->safe_psql('postgres', "ALTER SUBSCRIPTION sub ENABLE;");
+
$node_publisher->safe_psql( 'postgres',
"COMMIT PREPARED 'test_prepared_tab_full';");
$node_publisher->wait_for_catchup('sub');
--
2.43.0
^ permalink raw reply [nested|flat] 25+ messages in thread
* Re: Slow catchup of 2PC (twophase) transactions on replica in LR
@ 2024-05-09 02:14 Peter Smith <[email protected]>
parent: Hayato Kuroda (Fujitsu) <[email protected]>
3 siblings, 1 reply; 25+ messages in thread
From: Peter Smith @ 2024-05-09 02:14 UTC (permalink / raw)
To: Hayato Kuroda (Fujitsu) <[email protected]>; +Cc: [email protected] <[email protected]>; Amit Kapila <[email protected]>; Ajin Cherian <[email protected]>; Давыдов Виталий <[email protected]>
Hi Kuroda-san,
Thanks for addressing most of my v6-0001 review comments.
Below are some minor follow-up comments for v7-0001.
======
src/backend/access/transam/twophase.c
1. IsTwoPhaseTransactionGidForSubid
+/*
+ * IsTwoPhaseTransactionGidForSubid
+ * Check whether the given GID is formed by TwoPhaseTransactionGid.
+ */
+static bool
+IsTwoPhaseTransactionGidForSubid(Oid subid, char *gid)
I think the function comment should mention something about 'subid'.
SUGGESTION
Check whether the given GID (as formed by TwoPhaseTransactionGid) is
for the specified 'subid'.
======
src/backend/commands/subscriptioncmds.c
2. AlterSubscription
+ if (!opts.twophase &&
+ form->subtwophasestate == LOGICALREP_TWOPHASE_STATE_ENABLED &&
+ LookupGXactBySubid(subid))
+ /* Add error message */
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("cannot disable two_phase when uncommitted prepared
transactions present"),
+ errhint("Resolve these transactions and try again")));
The comment "/* Add error message */" seems unnecessary.
======
Kind Regards,
Peter Smith.
Fujitsu Australia
^ permalink raw reply [nested|flat] 25+ messages in thread
* Re: Slow catchup of 2PC (twophase) transactions on replica in LR
@ 2024-05-09 02:21 Peter Smith <[email protected]>
parent: Hayato Kuroda (Fujitsu) <[email protected]>
3 siblings, 1 reply; 25+ messages in thread
From: Peter Smith @ 2024-05-09 02:21 UTC (permalink / raw)
To: Hayato Kuroda (Fujitsu) <[email protected]>; +Cc: [email protected] <[email protected]>; Amit Kapila <[email protected]>; Ajin Cherian <[email protected]>; Давыдов Виталий <[email protected]>
Hi, Here are some review comments for v7-0002
======
Commit message
1.
IIUC there is quite a lot of subtlety and details about why the slot
option needs to be changed only when altering "true" to "false", but
not when altering "false" to "true".
It also should explain why PreventInTransactionBlock is only needed
when altering two_phase "true" to "false".
Please include a commit message to describe all those tricky details.
======
src/backend/commands/subscriptioncmds.c
2. AlterSubscription
- PreventInTransactionBlock(isTopLevel, "ALTER SUBSCRIPTION ... SET
(two_phase)");
+ if (!opts.twophase)
+ PreventInTransactionBlock(isTopLevel,
+ "ALTER SUBSCRIPTION ... SET (two_phase = off)");
IMO this needs a comment to explain why PreventInTransactionBlock is
only needed when changing the 'two_phase' option from on to off.
~~~
3. AlterSubscription
/*
* Try to acquire the connection necessary for altering slot.
*
* This has to be at the end because otherwise if there is an error while
* doing the database operations we won't be able to rollback altered
* slot.
*/
if (replaces[Anum_pg_subscription_subfailover - 1] ||
replaces[Anum_pg_subscription_subtwophasestate - 1])
{
bool must_use_password;
char *err;
WalReceiverConn *wrconn;
bool failover_needs_to_be_updated;
bool two_phase_needs_to_be_updated;
/* Load the library providing us libpq calls. */
load_file("libpqwalreceiver", false);
/* Try to connect to the publisher. */
must_use_password = sub->passwordrequired && !sub->ownersuperuser;
wrconn = walrcv_connect(sub->conninfo, true, true, must_use_password,
sub->name, &err);
if (!wrconn)
ereport(ERROR,
(errcode(ERRCODE_CONNECTION_FAILURE),
errmsg("could not connect to the publisher: %s", err)));
/*
* Consider which slot option must be altered.
*
* We must alter the failover option whenever subfailover is updated.
* Two_phase, however, is altered only when changing true to false.
*/
failover_needs_to_be_updated =
replaces[Anum_pg_subscription_subfailover - 1];
two_phase_needs_to_be_updated =
(replaces[Anum_pg_subscription_subtwophasestate - 1] &&
!opts.twophase);
PG_TRY();
{
if (two_phase_needs_to_be_updated || failover_needs_to_be_updated)
walrcv_alter_slot(wrconn, sub->slotname,
failover_needs_to_be_updated ? &opts.failover : NULL,
two_phase_needs_to_be_updated ? &opts.twophase : NULL);
}
PG_FINALLY();
{
walrcv_disconnect(wrconn);
}
PG_END_TRY();
}
3a.
The block comment "Consider which slot option must be altered..." says
WHEN those options need to be updated, but it doesn't say WHY. e.g.
why only update the 'two_phase' when it is being disabled but not when
it is being enabled? In other words, I think there needs to be more
background/reason details given in this comment.
~~~
3b.
Can't those 2 new variable assignments be done up-front and guard this
entire "if-block" instead of the current replaces[] guarding it? Then
the code is somewhat simplified.
SUGGESTION:
/*
* <improved comment here to explain these variables>
*/
update_failover = replaces[Anum_pg_subscription_subfailover - 1];
update_two_phase = (replaces[Anum_pg_subscription_subtwophasestate -
1] && !opts.twophase);
/*
* Try to acquire the connection necessary for altering slot.
*
* This has to be at the end because otherwise if there is an error while
* doing the database operations we won't be able to rollback altered
* slot.
*/
if (update_failover || update_two_phase)
{
...
/* Load the library providing us libpq calls. */
load_file("libpqwalreceiver", false);
/* Try to connect to the publisher. */
must_use_password = sub->passwordrequired && !sub->ownersuperuser;
wrconn = walrcv_connect(sub->conninfo, true, true,
must_use_password, sub->name, &err);
if (!wrconn)
ereport(ERROR, ...);
PG_TRY();
{
walrcv_alter_slot(wrconn, sub->slotname,
update_failover ? &opts.failover : NULL,
update_two_phase ? &opts.twophase : NULL);
}
PG_FINALLY();
{
walrcv_disconnect(wrconn);
}
PG_END_TRY();
}
======
.../libpqwalreceiver/libpqwalreceiver.c
4.
+ appendStringInfo(&cmd, "ALTER_REPLICATION_SLOT %s ( ",
+ quote_identifier(slotname));
+
+ if (failover)
+ appendStringInfo(&cmd, "FAILOVER %s ",
+ (*failover) ? "true" : "false");
+
+ if (two_phase)
+ appendStringInfo(&cmd, "TWO_PHASE %s%s ",
+ (*two_phase) ? "true" : "false",
+ failover ? ", " : "");
+
+ appendStringInfoString(&cmd, ");");
4a.
IIUC the comma logic here was broken in v7 when you swapped the order.
Anyway, IMO it will be better NOT to try combining that comma logic
with the existing appendStringInfo. Doing it separately is both easier
and less error-prone.
Furthermore, the parentheses like "(*two_phase)" instead of just
"*two_phase" seemed a bit overkill.
SUGGESTION:
+ if (failover)
+ appendStringInfo(&cmd, "FAILOVER %s",
+ *failover ? "true" : "false");
+
+ if (failover && two_phase)
+ appendStringInfo(&cmd, ", ");
+
+ if (two_phase)
+ appendStringInfo(&cmd, "TWO_PHASE %s",
+ *two_phase ? "true" : "false");
+
+ appendStringInfoString(&cmd, " );");
~~
4b.
Like I said above, IMO the current separator logic in v7 is broken. So
it is a bit concerning the tests all passed anyway. How did that
happen? I think this indicates that there needs to be an additional
test scenario where both 'failover' and 'two_phase' get altered at the
same time so this code gets exercised properly.
======
src/test/subscription/t/099_twophase_added.pl
5.
+# Define pre-existing tables on both nodes
Why say they are "pre-existing"? They are not pre-existing because you
are creating them right here!
~~~
6.
+######
+# Check the case that prepared transactions exist on publisher node
+######
I think this needs a slightly more detailed comment.
SUGGESTION (this is just an example, but you can surely improve it)
# Check the case that prepared transactions exist on the publisher node.
#
# Since two_phase is "off", then normally this PREPARE will do nothing until
# the COMMIT PREPARED, but in this test, we toggle the two_phase to "on" again
# before the COMMIT PREPARED happens.
~~~
7.
Maybe this test case needs a few more one-line comments for each of
the sub-steps. e.g.:
# prepare a transaction to insert some rows to the table
# verify the prepared tx is not yet replicated to the subscriber
(because 'two_phase = off')
# toggle the two_phase to 'on' *before* the COMMIT PREPARED
# verify the inserted rows got replicated ok
~~~
8.
IIUC this test will behave the same even if you DON'T do the toggle
'two_phase = on'. So I wonder is there something more you can do to
test this scenario more convincingly?
======
Kind Regards,
Peter Smith
Fujitsu Australia
^ permalink raw reply [nested|flat] 25+ messages in thread
* Re: Slow catchup of 2PC (twophase) transactions on replica in LR
@ 2024-05-09 06:11 Peter Smith <[email protected]>
parent: Hayato Kuroda (Fujitsu) <[email protected]>
3 siblings, 1 reply; 25+ messages in thread
From: Peter Smith @ 2024-05-09 06:11 UTC (permalink / raw)
To: Hayato Kuroda (Fujitsu) <[email protected]>; +Cc: [email protected] <[email protected]>; Amit Kapila <[email protected]>; Ajin Cherian <[email protected]>; Давыдов Виталий <[email protected]>
Hi, Here are some review comments for the patch v7-0003.
======
Commit Message
1.
The patch needs a commit message to describe the purpose and highlight
any limitations and other details.
======
doc/src/sgml/ref/alter_subscription.sgml
2.
+
+ <para>
+ The <literal>two_phase</literal> parameter can only be altered when the
+ subscription is disabled. When altering the parameter from
<literal>true</literal>
+ to <literal>false</literal>, the backend process checks prepared
+ transactions done by the logical replication worker and aborts them.
+ </para>
Here, the para is referring to "true" and "false" but earlier on this
page it talks about "twophase = off". IMO it is better to use a
consistent terminology like "on|off" everywhere instead of randomly
changing the way it is described each time.
======
src/backend/commands/subscriptioncmds.c
3. AlterSubscription
if (IsSet(opts.specified_opts, SUBOPT_TWOPHASE_COMMIT))
{
+ List *prepared_xacts = NIL;
This 'prepared_xacts' can be declared at a lower scrope because it is
only used if (!opts.twophase).
Furthermore, IIUC you don't need to assign NIL in the declaration
because there is no chance for it to be unassigned anyway.
~~~
4. AlterSubscription
+ /*
+ * The changed two_phase option (true->false) of the
+ * slot can't be rolled back.
+ */
PreventInTransactionBlock(isTopLevel,
"ALTER SUBSCRIPTION ... SET (two_phase = off)");
Here is another example of inconsistent mixing of the terminology
where the comment says "true"/"false" but the message says "off".
Let's keep everything consistent. (I prefer on|off).
~~~
5.
+ if (sub->twophasestate == LOGICALREP_TWOPHASE_STATE_ENABLED &&
+ (prepared_xacts = GetGidListBySubid(subid)) != NIL)
+ {
+ ListCell *cell;
+
+ /* Abort all listed transactions */
+ foreach(cell, prepared_xacts)
+ FinishPreparedTransaction((char *) lfirst(cell),
+ false);
+
+ list_free(prepared_xacts);
+ }
5A.
IIRC there is a cleaner way to write this loop without needing
ListCell variable -- e.g. foreach_ptr() macro?
~
5B.
Shouldn't this be using list_free_deep() so the pstrdup gid gets freed too?
======
src/test/subscription/t/099_twophase_added.pl
6.
+######
+# Check the case that prepared transactions exist on subscriber node
+######
+
Give some more detailed comments here similar to the review comment of
patch v7-0002 for the other part of this TAP test.
~~~
7. TAP test - comments
Same as for my v7-0002 review comments, I think this test case also
needs a few more one-line comments to describe the sub-steps. e.g.:
# prepare a transaction to insert some rows to the table
# verify the prepared tx is replicated to the subscriber (because
'two_phase = on')
# toggle the two_phase to 'off' *before* the COMMIT PREPARED
# verify the prepared tx got aborted
# do the COMMIT PREPARED (note that now two_phase is 'off')
# verify the inserted rows got replicated ok
~~~
8. TAP test - subscription name
It's better to rename the SUBSCRIPTION in this TAP test so you can
avoid getting log warnings like:
psql:<stdin>:4: WARNING: subscriptions created by regression test
cases should have names starting with "regress_"
psql:<stdin>:4: NOTICE: created replication slot "sub" on publisher
======
Kind Regards,
Peter Smith.
Fujitsu Australia
^ permalink raw reply [nested|flat] 25+ messages in thread
* Re: Slow catchup of 2PC (twophase) transactions on replica in LR
@ 2024-05-09 07:28 Peter Smith <[email protected]>
parent: Hayato Kuroda (Fujitsu) <[email protected]>
3 siblings, 1 reply; 25+ messages in thread
From: Peter Smith @ 2024-05-09 07:28 UTC (permalink / raw)
To: Hayato Kuroda (Fujitsu) <[email protected]>; +Cc: [email protected] <[email protected]>; Amit Kapila <[email protected]>; Ajin Cherian <[email protected]>; Давыдов Виталий <[email protected]>
Hi, Here are some review comments for patch v7-0004
======
Commit message
1.
A detailed commit message is needed to describe the purpose and
details of this patch.
======
doc/src/sgml/ref/alter_subscription.sgml
2. CREATE SUBSCRIPTION
Shouldn't there be an entry for "force_alter" parameter in the CREATE
SUBSCRIPTION "parameters" section, instead of just vaguely mentioning
it in passing when describing the "two_phase" in ALTER SUBSCRIPTION?
~
3. ALTER SUBSCRIPTION - alterable parameters
And shouldn't this new option also be named in the ALTER SUBSCRIPTION
list: "The parameters that can be altered are..."
======
src/backend/commands/subscriptioncmds.c
4.
XLogRecPtr lsn;
+ bool twophase_force;
} SubOpts;
IMO this field ought to be called 'force_alter' to be the same as the
option name. Sure, now it is only relevant for 'two_phase', but that
might not always be the case in the future.
~~~
5. AlterSubscription
+ /*
+ * Abort prepared transactions if force option is also
+ * specified. Otherwise raise an ERROR.
+ */
+ if (!opts.twophase_force)
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("cannot alter %s when there are prepared transactions",
+ "two_phase = false")));
+
5a.
/if force option is also specified/only if the 'force_alter' option is true/
~
5b.
"two_phase = false" -- IMO that should say "two_phase = off"
~
5c.
IMO this ereport should include a errhint to tell the user they can
use 'force_alter = true' to avoid getting this error.
~~~
6.
+ /* force_alter cannot be used standalone */
+ if (IsSet(opts.specified_opts, SUBOPT_FORCE_ALTER) &&
+ !IsSet(opts.specified_opts, SUBOPT_TWOPHASE_COMMIT))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("%s must be specified with %s",
+ "force_alter", "two_phase")));
+
IMO this rule is not necessary so the code should be removed. I think
using 'force_alter' standalone doesn't do anything at all (certainly,
it does no harm) so why add more complications (more rules, more code,
more tests) just for the sake of it?
======
src/test/subscription/t/099_twophase_added.pl
7.
+$node_subscriber->safe_psql('postgres',
+ "ALTER SUBSCRIPTION sub SET (two_phase = off, force_alter = on);");
"force" is a verb, so it is better to say 'force_alter = true' instead
of 'force_alter = on'.
~~~
8.
$result = $node_subscriber->safe_psql('postgres',
"SELECT count(*) FROM pg_prepared_xacts;");
is($result, q(0), "prepared transaction done by worker is aborted");
+$node_subscriber->safe_psql('postgres', "ALTER SUBSCRIPTION sub ENABLE;");
+
I felt the ENABLE statement should be above the SELECT statement so
that the code is more like it was before applying the patch.
======
Kind Regards,
Peter Smith.
Fujitsu Australia
^ permalink raw reply [nested|flat] 25+ messages in thread
* RE: Slow catchup of 2PC (twophase) transactions on replica in LR
@ 2024-05-09 08:26 Hayato Kuroda (Fujitsu) <[email protected]>
parent: Peter Smith <[email protected]>
0 siblings, 0 replies; 25+ messages in thread
From: Hayato Kuroda (Fujitsu) @ 2024-05-09 08:26 UTC (permalink / raw)
To: 'Peter Smith' <[email protected]>; +Cc: [email protected] <[email protected]>; Amit Kapila <[email protected]>; Ajin Cherian <[email protected]>; Давыдов Виталий <[email protected]>
Dear Peter,
Thanks for reviewing! The patch will be posted in the upcoming post.
> ======
> src/backend/access/transam/twophase.c
>
> 1. IsTwoPhaseTransactionGidForSubid
>
> +/*
> + * IsTwoPhaseTransactionGidForSubid
> + * Check whether the given GID is formed by TwoPhaseTransactionGid.
> + */
> +static bool
> +IsTwoPhaseTransactionGidForSubid(Oid subid, char *gid)
>
> I think the function comment should mention something about 'subid'.
>
> SUGGESTION
> Check whether the given GID (as formed by TwoPhaseTransactionGid) is
> for the specified 'subid'.
Fixed.
> src/backend/commands/subscriptioncmds.c
>
> 2. AlterSubscription
>
> + if (!opts.twophase &&
> + form->subtwophasestate == LOGICALREP_TWOPHASE_STATE_ENABLED
> &&
> + LookupGXactBySubid(subid))
> + /* Add error message */
> + ereport(ERROR,
> + (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
> + errmsg("cannot disable two_phase when uncommitted prepared
> transactions present"),
> + errhint("Resolve these transactions and try again")));
>
> The comment "/* Add error message */" seems unnecessary.
Yeah, this was an internal flag. Removed.
Best Regards,
Hayato Kuroda
FUJITSU LIMITED
https://www.fujitsu.com/
^ permalink raw reply [nested|flat] 25+ messages in thread
* RE: Slow catchup of 2PC (twophase) transactions on replica in LR
@ 2024-05-09 08:54 Hayato Kuroda (Fujitsu) <[email protected]>
parent: Peter Smith <[email protected]>
0 siblings, 0 replies; 25+ messages in thread
From: Hayato Kuroda (Fujitsu) @ 2024-05-09 08:54 UTC (permalink / raw)
To: 'Peter Smith' <[email protected]>; +Cc: [email protected] <[email protected]>; Amit Kapila <[email protected]>; Ajin Cherian <[email protected]>; Давыдов Виталий <[email protected]>
Dear Peter,
> ======
> Commit message
>
> 1.
> IIUC there is quite a lot of subtlety and details about why the slot
> option needs to be changed only when altering "true" to "false", but
> not when altering "false" to "true".
>
> It also should explain why PreventInTransactionBlock is only needed
> when altering two_phase "true" to "false".
>
> Please include a commit message to describe all those tricky details.
Added.
> ======
> src/backend/commands/subscriptioncmds.c
>
> 2. AlterSubscription
>
> - PreventInTransactionBlock(isTopLevel, "ALTER SUBSCRIPTION ... SET
> (two_phase)");
> + if (!opts.twophase)
> + PreventInTransactionBlock(isTopLevel,
> + "ALTER SUBSCRIPTION ... SET (two_phase = off)");
>
> IMO this needs a comment to explain why PreventInTransactionBlock is
> only needed when changing the 'two_phase' option from on to off.
Added. Thoutht?
> 3. AlterSubscription
>
> /*
> * Try to acquire the connection necessary for altering slot.
> *
> * This has to be at the end because otherwise if there is an error while
> * doing the database operations we won't be able to rollback altered
> * slot.
> */
> if (replaces[Anum_pg_subscription_subfailover - 1] ||
> replaces[Anum_pg_subscription_subtwophasestate - 1])
> {
> bool must_use_password;
> char *err;
> WalReceiverConn *wrconn;
> bool failover_needs_to_be_updated;
> bool two_phase_needs_to_be_updated;
>
> /* Load the library providing us libpq calls. */
> load_file("libpqwalreceiver", false);
>
> /* Try to connect to the publisher. */
> must_use_password = sub->passwordrequired && !sub->ownersuperuser;
> wrconn = walrcv_connect(sub->conninfo, true, true, must_use_password,
> sub->name, &err);
> if (!wrconn)
> ereport(ERROR,
> (errcode(ERRCODE_CONNECTION_FAILURE),
> errmsg("could not connect to the publisher: %s", err)));
>
> /*
> * Consider which slot option must be altered.
> *
> * We must alter the failover option whenever subfailover is updated.
> * Two_phase, however, is altered only when changing true to false.
> */
> failover_needs_to_be_updated =
> replaces[Anum_pg_subscription_subfailover - 1];
> two_phase_needs_to_be_updated =
> (replaces[Anum_pg_subscription_subtwophasestate - 1] &&
> !opts.twophase);
>
> PG_TRY();
> {
> if (two_phase_needs_to_be_updated || failover_needs_to_be_updated)
> walrcv_alter_slot(wrconn, sub->slotname,
> failover_needs_to_be_updated ? &opts.failover : NULL,
> two_phase_needs_to_be_updated ? &opts.twophase : NULL);
> }
> PG_FINALLY();
> {
> walrcv_disconnect(wrconn);
> }
> PG_END_TRY();
> }
>
> 3a.
> The block comment "Consider which slot option must be altered..." says
> WHEN those options need to be updated, but it doesn't say WHY. e.g.
> why only update the 'two_phase' when it is being disabled but not when
> it is being enabled? In other words, I think there needs to be more
> background/reason details given in this comment.
>
> ~~~
>
> 3b.
> Can't those 2 new variable assignments be done up-front and guard this
> entire "if-block" instead of the current replaces[] guarding it? Then
> the code is somewhat simplified.
>
> SUGGESTION:
> /*
> * <improved comment here to explain these variables>
> */
> update_failover = replaces[Anum_pg_subscription_subfailover - 1];
> update_two_phase = (replaces[Anum_pg_subscription_subtwophasestate -
> 1] && !opts.twophase);
>
> /*
> * Try to acquire the connection necessary for altering slot.
> *
> * This has to be at the end because otherwise if there is an error while
> * doing the database operations we won't be able to rollback altered
> * slot.
> */
> if (update_failover || update_two_phase)
> {
> ...
>
> /* Load the library providing us libpq calls. */
> load_file("libpqwalreceiver", false);
>
> /* Try to connect to the publisher. */
> must_use_password = sub->passwordrequired && !sub->ownersuperuser;
> wrconn = walrcv_connect(sub->conninfo, true, true,
> must_use_password, sub->name, &err);
> if (!wrconn)
> ereport(ERROR, ...);
>
> PG_TRY();
> {
> walrcv_alter_slot(wrconn, sub->slotname,
> update_failover ? &opts.failover : NULL,
> update_two_phase ? &opts.twophase : NULL);
> }
> PG_FINALLY();
> {
> walrcv_disconnect(wrconn);
> }
> PG_END_TRY();
> }
Two variables were added and comments were updated.
> .../libpqwalreceiver/libpqwalreceiver.c
>
> 4.
> + appendStringInfo(&cmd, "ALTER_REPLICATION_SLOT %s ( ",
> + quote_identifier(slotname));
> +
> + if (failover)
> + appendStringInfo(&cmd, "FAILOVER %s ",
> + (*failover) ? "true" : "false");
> +
> + if (two_phase)
> + appendStringInfo(&cmd, "TWO_PHASE %s%s ",
> + (*two_phase) ? "true" : "false",
> + failover ? ", " : "");
> +
> + appendStringInfoString(&cmd, ");");
>
> 4a.
> IIUC the comma logic here was broken in v7 when you swapped the order.
> Anyway, IMO it will be better NOT to try combining that comma logic
> with the existing appendStringInfo. Doing it separately is both easier
> and less error-prone.
>
> Furthermore, the parentheses like "(*two_phase)" instead of just
> "*two_phase" seemed a bit overkill.
>
> SUGGESTION:
> + if (failover)
> + appendStringInfo(&cmd, "FAILOVER %s",
> + *failover ? "true" : "false");
> +
> + if (failover && two_phase)
> + appendStringInfo(&cmd, ", ");
> +
> + if (two_phase)
> + appendStringInfo(&cmd, "TWO_PHASE %s",
> + *two_phase ? "true" : "false");
> +
> + appendStringInfoString(&cmd, " );");
Fixed.
> 4b.
> Like I said above, IMO the current separator logic in v7 is broken. So
> it is a bit concerning the tests all passed anyway. How did that
> happen? I think this indicates that there needs to be an additional
> test scenario where both 'failover' and 'two_phase' get altered at the
> same time so this code gets exercised properly.
Right, it was added.
> ======
> src/test/subscription/t/099_twophase_added.pl
>
> 5.
> +# Define pre-existing tables on both nodes
>
> Why say they are "pre-existing"? They are not pre-existing because you
> are creating them right here!
Removed the word.
> 6.
> +######
> +# Check the case that prepared transactions exist on publisher node
> +######
>
> I think this needs a slightly more detailed comment.
>
> SUGGESTION (this is just an example, but you can surely improve it)
>
> # Check the case that prepared transactions exist on the publisher node.
> #
> # Since two_phase is "off", then normally this PREPARE will do nothing until
> # the COMMIT PREPARED, but in this test, we toggle the two_phase to "on" again
> # before the COMMIT PREPARED happens.
Changed with adjustments.
> 7.
> Maybe this test case needs a few more one-line comments for each of
> the sub-steps. e.g.:
>
> # prepare a transaction to insert some rows to the table
>
> # verify the prepared tx is not yet replicated to the subscriber
> (because 'two_phase = off')
>
> # toggle the two_phase to 'on' *before* the COMMIT PREPARED
>
> # verify the inserted rows got replicated ok
Modified like yours, but changed based on the suggestion by Grammarly.
> 8.
> IIUC this test will behave the same even if you DON'T do the toggle
> 'two_phase = on'. So I wonder is there something more you can do to
> test this scenario more convincingly?
I found an indicator. When the apply starts, it outputs the current status of
two_phase option. I added wait_for_log() to ensure below appeared. Thought?
```
ereport(DEBUG1,
(errmsg_internal("logical replication apply worker for subscription \"%s\" two_phase is %s",
MySubscription->name,
MySubscription->twophasestate == LOGICALREP_TWOPHASE_STATE_DISABLED ? "DISABLED" :
MySubscription->twophasestate == LOGICALREP_TWOPHASE_STATE_PENDING ? "PENDING" :
MySubscription->twophasestate == LOGICALREP_TWOPHASE_STATE_ENABLED ? "ENABLED" :
"?")));
```
Best Regards,
Hayato Kuroda
FUJITSU LIMITED
https://www.fujitsu.com/
^ permalink raw reply [nested|flat] 25+ messages in thread
* RE: Slow catchup of 2PC (twophase) transactions on replica in LR
@ 2024-05-09 09:10 Hayato Kuroda (Fujitsu) <[email protected]>
parent: Peter Smith <[email protected]>
0 siblings, 0 replies; 25+ messages in thread
From: Hayato Kuroda (Fujitsu) @ 2024-05-09 09:10 UTC (permalink / raw)
To: 'Peter Smith' <[email protected]>; +Cc: [email protected] <[email protected]>; Amit Kapila <[email protected]>; Ajin Cherian <[email protected]>; Давыдов Виталий <[email protected]>
Dear Peter,
> Commit Message
>
> 1.
> The patch needs a commit message to describe the purpose and highlight
> any limitations and other details.
Added.
> ======
> doc/src/sgml/ref/alter_subscription.sgml
>
> 2.
> +
> + <para>
> + The <literal>two_phase</literal> parameter can only be altered when
> the
> + subscription is disabled. When altering the parameter from
> <literal>true</literal>
> + to <literal>false</literal>, the backend process checks prepared
> + transactions done by the logical replication worker and aborts them.
> + </para>
>
> Here, the para is referring to "true" and "false" but earlier on this
> page it talks about "twophase = off". IMO it is better to use a
> consistent terminology like "on|off" everywhere instead of randomly
> changing the way it is described each time.
I checked contents and changed to "on|off".
> ======
> src/backend/commands/subscriptioncmds.c
>
> 3. AlterSubscription
>
> if (IsSet(opts.specified_opts, SUBOPT_TWOPHASE_COMMIT))
> {
> + List *prepared_xacts = NIL;
>
> This 'prepared_xacts' can be declared at a lower scrope because it is
> only used if (!opts.twophase).
>
> Furthermore, IIUC you don't need to assign NIL in the declaration
> because there is no chance for it to be unassigned anyway.
Made the namespace narrower and initialization was removed.
> ~~~
>
> 4. AlterSubscription
>
> + /*
> + * The changed two_phase option (true->false) of the
> + * slot can't be rolled back.
> + */
> PreventInTransactionBlock(isTopLevel,
> "ALTER SUBSCRIPTION ... SET (two_phase = off)");
>
> Here is another example of inconsistent mixing of the terminology
> where the comment says "true"/"false" but the message says "off".
> Let's keep everything consistent. (I prefer on|off).
Modified.
> ~~~
>
> 5.
> + if (sub->twophasestate == LOGICALREP_TWOPHASE_STATE_ENABLED &&
> + (prepared_xacts = GetGidListBySubid(subid)) != NIL)
> + {
> + ListCell *cell;
> +
> + /* Abort all listed transactions */
> + foreach(cell, prepared_xacts)
> + FinishPreparedTransaction((char *) lfirst(cell),
> + false);
> +
> + list_free(prepared_xacts);
> + }
>
> 5A.
> IIRC there is a cleaner way to write this loop without needing
> ListCell variable -- e.g. foreach_ptr() macro?
Changed.
> 5B.
> Shouldn't this be using list_free_deep() so the pstrdup gid gets freed too?
Yeah, fixed.
> ======
> src/test/subscription/t/099_twophase_added.pl
>
> 6.
> +######
> +# Check the case that prepared transactions exist on subscriber node
> +######
> +
>
> Give some more detailed comments here similar to the review comment of
> patch v7-0002 for the other part of this TAP test.
>
> ~~~
>
> 7. TAP test - comments
>
> Same as for my v7-0002 review comments, I think this test case also
> needs a few more one-line comments to describe the sub-steps. e.g.:
>
> # prepare a transaction to insert some rows to the table
>
> # verify the prepared tx is replicated to the subscriber (because
> 'two_phase = on')
>
> # toggle the two_phase to 'off' *before* the COMMIT PREPARED
>
> # verify the prepared tx got aborted
>
> # do the COMMIT PREPARED (note that now two_phase is 'off')
>
> # verify the inserted rows got replicated ok
They were fixed based on your previous comments.
>
> 8. TAP test - subscription name
>
> It's better to rename the SUBSCRIPTION in this TAP test so you can
> avoid getting log warnings like:
>
> psql:<stdin>:4: WARNING: subscriptions created by regression test
> cases should have names starting with "regress_"
> psql:<stdin>:4: NOTICE: created replication slot "sub" on publisher
Modified, but it was included in 0001.
Best Regards,
Hayato Kuroda
FUJITSU LIMITED
https://www.fujitsu.com/
^ permalink raw reply [nested|flat] 25+ messages in thread
* RE: Slow catchup of 2PC (twophase) transactions on replica in LR
@ 2024-05-09 09:15 Hayato Kuroda (Fujitsu) <[email protected]>
parent: Peter Smith <[email protected]>
0 siblings, 3 replies; 25+ messages in thread
From: Hayato Kuroda (Fujitsu) @ 2024-05-09 09:15 UTC (permalink / raw)
To: 'Peter Smith' <[email protected]>; +Cc: [email protected] <[email protected]>; Amit Kapila <[email protected]>; Ajin Cherian <[email protected]>; Давыдов Виталий <[email protected]>
Dear Peter,
>
> ======
> Commit message
>
> 1.
> A detailed commit message is needed to describe the purpose and
> details of this patch.
Added.
> ======
> doc/src/sgml/ref/alter_subscription.sgml
>
> 2. CREATE SUBSCRIPTION
>
> Shouldn't there be an entry for "force_alter" parameter in the CREATE
> SUBSCRIPTION "parameters" section, instead of just vaguely mentioning
> it in passing when describing the "two_phase" in ALTER SUBSCRIPTION?
>
> 3. ALTER SUBSCRIPTION - alterable parameters
>
> And shouldn't this new option also be named in the ALTER SUBSCRIPTION
> list: "The parameters that can be altered are..."
Hmm, but the parameter cannot be used for CREATE SUBSCRIPTION. Should we
modify to accept and add the description in the doc? This was not accepted.
> ======
> src/backend/commands/subscriptioncmds.c
>
> 4.
> XLogRecPtr lsn;
> + bool twophase_force;
> } SubOpts;
>
> IMO this field ought to be called 'force_alter' to be the same as the
> option name. Sure, now it is only relevant for 'two_phase', but that
> might not always be the case in the future.
Modified.
> 5. AlterSubscription
>
> + /*
> + * Abort prepared transactions if force option is also
> + * specified. Otherwise raise an ERROR.
> + */
> + if (!opts.twophase_force)
> + ereport(ERROR,
> + (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
> + errmsg("cannot alter %s when there are prepared transactions",
> + "two_phase = false")));
> +
>
> 5a.
> /if force option is also specified/only if the 'force_alter' option is true/
Modified.
>
> 5b.
> "two_phase = false" -- IMO that should say "two_phase = off"
Modified.
> 5c.
> IMO this ereport should include a errhint to tell the user they can
> use 'force_alter = true' to avoid getting this error.
Hint was added.
> 6.
>
> + /* force_alter cannot be used standalone */
> + if (IsSet(opts.specified_opts, SUBOPT_FORCE_ALTER) &&
> + !IsSet(opts.specified_opts, SUBOPT_TWOPHASE_COMMIT))
> + ereport(ERROR,
> + (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
> + errmsg("%s must be specified with %s",
> + "force_alter", "two_phase")));
> +
>
> IMO this rule is not necessary so the code should be removed. I think
> using 'force_alter' standalone doesn't do anything at all (certainly,
> it does no harm) so why add more complications (more rules, more code,
> more tests) just for the sake of it?
Removed. So standalone 'force_alter' is now no-op.
> src/test/subscription/t/099_twophase_added.pl
>
> 7.
> +$node_subscriber->safe_psql('postgres',
> + "ALTER SUBSCRIPTION sub SET (two_phase = off, force_alter = on);");
>
> "force" is a verb, so it is better to say 'force_alter = true' instead
> of 'force_alter = on'.
Fixed. Actually not sure it is better because I'm not a native.
> 8.
> $result = $node_subscriber->safe_psql('postgres',
> "SELECT count(*) FROM pg_prepared_xacts;");
> is($result, q(0), "prepared transaction done by worker is aborted");
>
> +$node_subscriber->safe_psql('postgres', "ALTER SUBSCRIPTION sub
> ENABLE;");
> +
>
> I felt the ENABLE statement should be above the SELECT statement so
> that the code is more like it was before applying the patch.
Fixed.
Please see attached patch set.
Best Regards,
Hayato Kuroda
FUJITSU LIMITED
https://www.fujitsu.com/
Attachments:
[application/octet-stream] v8-0001-Allow-altering-of-two_phase-option-of-a-SUBSCRIPT.patch (25.5K, ../../OSBPR01MB2552F738ACF1DA6838025C4FF5E62@OSBPR01MB2552.jpnprd01.prod.outlook.com/2-v8-0001-Allow-altering-of-two_phase-option-of-a-SUBSCRIPT.patch)
download | inline diff:
From f7c0476226447793353463b32286410f7b960027 Mon Sep 17 00:00:00 2001
From: Ajin Cherian <[email protected]>
Date: Fri, 5 Apr 2024 06:47:18 -0400
Subject: [PATCH v8 1/4] Allow altering of two_phase option of a SUBSCRIPTION
This patch allows the user to alter the 'two_phase' option of a subscriber provided no
uncommitted prepared transactions are pending on that subscription.
Author: Cherian Ajin, Hayato Kuroda
---
doc/src/sgml/ref/alter_subscription.sgml | 12 ++--
src/backend/access/transam/twophase.c | 62 ++++++++++++++++
src/backend/commands/subscriptioncmds.c | 67 +++++++++++++----
.../libpqwalreceiver/libpqwalreceiver.c | 9 +--
src/backend/replication/logical/launcher.c | 22 ++++++
src/backend/replication/logical/worker.c | 21 +-----
src/backend/replication/slot.c | 18 ++++-
src/backend/replication/walsender.c | 18 ++++-
src/bin/psql/tab-complete.c | 2 +-
src/include/access/twophase.h | 5 ++
src/include/replication/slot.h | 3 +-
src/include/replication/walreceiver.h | 11 +--
src/include/replication/worker_internal.h | 1 +
src/test/regress/expected/subscription.out | 5 +-
src/test/regress/sql/subscription.sql | 5 +-
src/test/subscription/t/021_twophase.pl | 71 ++++++++++++++++++-
16 files changed, 269 insertions(+), 63 deletions(-)
diff --git a/doc/src/sgml/ref/alter_subscription.sgml b/doc/src/sgml/ref/alter_subscription.sgml
index a78c1c3a47..88e9a72147 100644
--- a/doc/src/sgml/ref/alter_subscription.sgml
+++ b/doc/src/sgml/ref/alter_subscription.sgml
@@ -68,8 +68,9 @@ ALTER SUBSCRIPTION <replaceable class="parameter">name</replaceable> RENAME TO <
<para>
Commands <command>ALTER SUBSCRIPTION ... REFRESH PUBLICATION</command>,
<command>ALTER SUBSCRIPTION ... {SET|ADD|DROP} PUBLICATION ...</command>
- with <literal>refresh</literal> option as <literal>true</literal> and
- <command>ALTER SUBSCRIPTION ... SET (failover = on|off)</command>
+ with <literal>refresh</literal> option as <literal>true</literal>,
+ <command>ALTER SUBSCRIPTION ... SET (failover = on|off)</command> and
+ <command>ALTER SUBSCRIPTION ... SET (two_phase = on|off)</command>
cannot be executed inside a transaction block.
These commands also cannot be executed when the subscription has
@@ -228,9 +229,12 @@ ALTER SUBSCRIPTION <replaceable class="parameter">name</replaceable> RENAME TO <
<link linkend="sql-createsubscription-params-with-disable-on-error"><literal>disable_on_error</literal></link>,
<link linkend="sql-createsubscription-params-with-password-required"><literal>password_required</literal></link>,
<link linkend="sql-createsubscription-params-with-run-as-owner"><literal>run_as_owner</literal></link>,
- <link linkend="sql-createsubscription-params-with-origin"><literal>origin</literal></link>, and
- <link linkend="sql-createsubscription-params-with-failover"><literal>failover</literal></link>.
+ <link linkend="sql-createsubscription-params-with-origin"><literal>origin</literal></link>,
+ <link linkend="sql-createsubscription-params-with-failover"><literal>failover</literal></link>, and
+ <link linkend="sql-createsubscription-params-with-two-phase"><literal>two_phase</literal></link>.
Only a superuser can set <literal>password_required = false</literal>.
+ The <literal>two_phase</literal> parameter can only be altered when the
+ subscription is disabled.
</para>
<para>
diff --git a/src/backend/access/transam/twophase.c b/src/backend/access/transam/twophase.c
index 8090ac9fc1..66fa591eb5 100644
--- a/src/backend/access/transam/twophase.c
+++ b/src/backend/access/transam/twophase.c
@@ -2682,3 +2682,65 @@ LookupGXact(const char *gid, XLogRecPtr prepare_end_lsn,
LWLockRelease(TwoPhaseStateLock);
return found;
}
+
+/*
+ * TwoPhaseTransactionGid
+ * Form the prepared transaction GID for two_phase transactions.
+ *
+ * Return the GID in the supplied buffer.
+ */
+void
+TwoPhaseTransactionGid(Oid subid, TransactionId xid, char *gid, int szgid)
+{
+ Assert(subid != InvalidRepOriginId);
+
+ if (!TransactionIdIsValid(xid))
+ ereport(ERROR,
+ (errcode(ERRCODE_PROTOCOL_VIOLATION),
+ errmsg_internal("invalid two-phase transaction ID")));
+
+ snprintf(gid, szgid, "pg_gid_%u_%u", subid, xid);
+}
+
+/*
+ * IsTwoPhaseTransactionGidForSubid
+ * Check whether the given GID (as formed by TwoPhaseTransactionGid) is
+ * for the specified 'subid'.
+ */
+static bool
+IsTwoPhaseTransactionGidForSubid(Oid subid, char *gid)
+{
+ int ret;
+ Oid subid_written;
+ TransactionId xid;
+
+ ret = sscanf(gid, "pg_gid_%u_%u", &subid_written, &xid);
+
+ return (ret == 2 && subid == subid_written);
+}
+
+/*
+ * LookupGXactBySubid
+ * Check if the prepared transaction done by apply worker exists.
+ */
+bool
+LookupGXactBySubid(Oid subid)
+{
+ bool found = false;
+
+ LWLockAcquire(TwoPhaseStateLock, LW_SHARED);
+ for (int i = 0; i < TwoPhaseState->numPrepXacts; i++)
+ {
+ GlobalTransaction gxact = TwoPhaseState->prepXacts[i];
+
+ /* Ignore not-yet-valid GIDs. */
+ if (gxact->valid &&
+ IsTwoPhaseTransactionGidForSubid(subid, gxact->gid))
+ {
+ found = true;
+ break;
+ }
+ }
+ LWLockRelease(TwoPhaseStateLock);
+ return found;
+}
diff --git a/src/backend/commands/subscriptioncmds.c b/src/backend/commands/subscriptioncmds.c
index e407428dbc..90d967eb7c 100644
--- a/src/backend/commands/subscriptioncmds.c
+++ b/src/backend/commands/subscriptioncmds.c
@@ -16,6 +16,7 @@
#include "access/htup_details.h"
#include "access/table.h"
+#include "access/twophase.h"
#include "access/xact.h"
#include "catalog/catalog.h"
#include "catalog/dependency.h"
@@ -1143,7 +1144,8 @@ AlterSubscription(ParseState *pstate, AlterSubscriptionStmt *stmt,
{
supported_opts = (SUBOPT_SLOT_NAME |
SUBOPT_SYNCHRONOUS_COMMIT | SUBOPT_BINARY |
- SUBOPT_STREAMING | SUBOPT_DISABLE_ON_ERR |
+ SUBOPT_STREAMING | SUBOPT_TWOPHASE_COMMIT |
+ SUBOPT_DISABLE_ON_ERR |
SUBOPT_PASSWORD_REQUIRED |
SUBOPT_RUN_AS_OWNER | SUBOPT_FAILOVER |
SUBOPT_ORIGIN);
@@ -1151,6 +1153,52 @@ AlterSubscription(ParseState *pstate, AlterSubscriptionStmt *stmt,
parse_subscription_options(pstate, stmt->options,
supported_opts, &opts);
+ if (IsSet(opts.specified_opts, SUBOPT_TWOPHASE_COMMIT))
+ {
+ /*
+ * Do not allow changing the two_phase option if the
+ * subscription is enabled. This is because the two_phase
+ * option of the slot on the publisher cannot be modified
+ * if the slot is currently acquired by the apply worker.
+ */
+ if (form->subenabled)
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("cannot set %s for enabled subscription",
+ "two_phase")));
+
+ /*
+ * Stop all the subscription workers, just in case. Workers
+ * may still survive even if the subscription is disabled.
+ */
+ logicalrep_workers_stop(subid);
+
+ /*
+ * two_phase cannot be disabled if there are any
+ * uncommitted prepared transactions present.
+ */
+ if (!opts.twophase &&
+ form->subtwophasestate == LOGICALREP_TWOPHASE_STATE_ENABLED &&
+ LookupGXactBySubid(subid))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("cannot disable two_phase when uncommitted prepared transactions present"),
+ errhint("Resolve these transactions and try again")));
+
+ /*
+ * The changed two_phase option of the slot can't be rolled
+ * back.
+ */
+ PreventInTransactionBlock(isTopLevel, "ALTER SUBSCRIPTION ... SET (two_phase)");
+
+ /* Change system catalog acoordingly */
+ values[Anum_pg_subscription_subtwophasestate - 1] =
+ CharGetDatum(opts.twophase ?
+ LOGICALREP_TWOPHASE_STATE_PENDING :
+ LOGICALREP_TWOPHASE_STATE_DISABLED);
+ replaces[Anum_pg_subscription_subtwophasestate - 1] = true;
+ }
+
if (IsSet(opts.specified_opts, SUBOPT_SLOT_NAME))
{
/*
@@ -1505,7 +1553,8 @@ AlterSubscription(ParseState *pstate, AlterSubscriptionStmt *stmt,
* doing the database operations we won't be able to rollback altered
* slot.
*/
- if (replaces[Anum_pg_subscription_subfailover - 1])
+ if (replaces[Anum_pg_subscription_subfailover - 1] ||
+ replaces[Anum_pg_subscription_subtwophasestate - 1])
{
bool must_use_password;
char *err;
@@ -1525,7 +1574,7 @@ AlterSubscription(ParseState *pstate, AlterSubscriptionStmt *stmt,
PG_TRY();
{
- walrcv_alter_slot(wrconn, sub->slotname, opts.failover);
+ walrcv_alter_slot(wrconn, sub->slotname, opts.failover, opts.twophase);
}
PG_FINALLY();
{
@@ -1562,7 +1611,6 @@ DropSubscription(DropSubscriptionStmt *stmt, bool isTopLevel)
char *subname;
char *conninfo;
char *slotname;
- List *subworkers;
ListCell *lc;
char originname[NAMEDATALEN];
char *err = NULL;
@@ -1672,16 +1720,7 @@ DropSubscription(DropSubscriptionStmt *stmt, bool isTopLevel)
* New workers won't be started because we hold an exclusive lock on the
* subscription till the end of the transaction.
*/
- LWLockAcquire(LogicalRepWorkerLock, LW_SHARED);
- subworkers = logicalrep_workers_find(subid, false);
- LWLockRelease(LogicalRepWorkerLock);
- foreach(lc, subworkers)
- {
- LogicalRepWorker *w = (LogicalRepWorker *) lfirst(lc);
-
- logicalrep_worker_stop(w->subid, w->relid);
- }
- list_free(subworkers);
+ logicalrep_workers_stop(subid);
/*
* Remove the no-longer-useful entry in the launcher's table of apply
diff --git a/src/backend/replication/libpqwalreceiver/libpqwalreceiver.c b/src/backend/replication/libpqwalreceiver/libpqwalreceiver.c
index 3c2b1bb496..998bbd517a 100644
--- a/src/backend/replication/libpqwalreceiver/libpqwalreceiver.c
+++ b/src/backend/replication/libpqwalreceiver/libpqwalreceiver.c
@@ -80,7 +80,7 @@ static char *libpqrcv_create_slot(WalReceiverConn *conn,
CRSSnapshotAction snapshot_action,
XLogRecPtr *lsn);
static void libpqrcv_alter_slot(WalReceiverConn *conn, const char *slotname,
- bool failover);
+ bool failover, bool two_phase);
static pid_t libpqrcv_get_backend_pid(WalReceiverConn *conn);
static WalRcvExecResult *libpqrcv_exec(WalReceiverConn *conn,
const char *query,
@@ -1121,15 +1121,16 @@ libpqrcv_create_slot(WalReceiverConn *conn, const char *slotname,
*/
static void
libpqrcv_alter_slot(WalReceiverConn *conn, const char *slotname,
- bool failover)
+ bool failover, bool two_phase)
{
StringInfoData cmd;
PGresult *res;
initStringInfo(&cmd);
- appendStringInfo(&cmd, "ALTER_REPLICATION_SLOT %s ( FAILOVER %s )",
+ appendStringInfo(&cmd, "ALTER_REPLICATION_SLOT %s ( FAILOVER %s, TWO_PHASE %s )",
quote_identifier(slotname),
- failover ? "true" : "false");
+ failover ? "true" : "false",
+ two_phase ? "true" : "false");
res = libpqrcv_PQexec(conn->streamConn, cmd.data);
pfree(cmd.data);
diff --git a/src/backend/replication/logical/launcher.c b/src/backend/replication/logical/launcher.c
index 66070e9131..548f6e0edb 100644
--- a/src/backend/replication/logical/launcher.c
+++ b/src/backend/replication/logical/launcher.c
@@ -623,6 +623,28 @@ logicalrep_worker_stop(Oid subid, Oid relid)
LWLockRelease(LogicalRepWorkerLock);
}
+/*
+ * Stop all the subscription workers.
+ */
+void
+logicalrep_workers_stop(Oid subid)
+{
+ List *subworkers;
+ ListCell *lc;
+
+ LWLockAcquire(LogicalRepWorkerLock, LW_SHARED);
+ /* XXX clarify the reason why not only running workers are listed. */
+ subworkers = logicalrep_workers_find(subid, false);
+ LWLockRelease(LogicalRepWorkerLock);
+ foreach(lc, subworkers)
+ {
+ LogicalRepWorker *w = (LogicalRepWorker *) lfirst(lc);
+
+ logicalrep_worker_stop(w->subid, w->relid);
+ }
+ list_free(subworkers);
+}
+
/*
* Stop the given logical replication parallel apply worker.
*
diff --git a/src/backend/replication/logical/worker.c b/src/backend/replication/logical/worker.c
index b5a80fe3e8..dcf656fd45 100644
--- a/src/backend/replication/logical/worker.c
+++ b/src/backend/replication/logical/worker.c
@@ -402,7 +402,6 @@ static void apply_handle_tuple_routing(ApplyExecutionData *edata,
CmdType operation);
/* Compute GID for two_phase transactions */
-static void TwoPhaseTransactionGid(Oid subid, TransactionId xid, char *gid, int szgid);
/* Functions for skipping changes */
static void maybe_start_skipping_changes(XLogRecPtr finish_lsn);
@@ -3911,7 +3910,7 @@ maybe_reread_subscription(void)
/* !slotname should never happen when enabled is true. */
Assert(newsub->slotname);
- /* two-phase should not be altered */
+ /* two-phase cannot be altered while the worker exists */
Assert(newsub->twophasestate == MySubscription->twophasestate);
/*
@@ -4396,24 +4395,6 @@ cleanup_subxact_info()
subxact_data.nsubxacts_max = 0;
}
-/*
- * Form the prepared transaction GID for two_phase transactions.
- *
- * Return the GID in the supplied buffer.
- */
-static void
-TwoPhaseTransactionGid(Oid subid, TransactionId xid, char *gid, int szgid)
-{
- Assert(subid != InvalidRepOriginId);
-
- if (!TransactionIdIsValid(xid))
- ereport(ERROR,
- (errcode(ERRCODE_PROTOCOL_VIOLATION),
- errmsg_internal("invalid two-phase transaction ID")));
-
- snprintf(gid, szgid, "pg_gid_%u_%u", subid, xid);
-}
-
/*
* Common function to run the apply loop with error handling. Disable the
* subscription, if necessary.
diff --git a/src/backend/replication/slot.c b/src/backend/replication/slot.c
index aa4ea387da..d0c8d5a4df 100644
--- a/src/backend/replication/slot.c
+++ b/src/backend/replication/slot.c
@@ -804,8 +804,10 @@ ReplicationSlotDrop(const char *name, bool nowait)
* Change the definition of the slot identified by the specified name.
*/
void
-ReplicationSlotAlter(const char *name, bool failover)
+ReplicationSlotAlter(const char *name, bool failover, bool two_phase)
{
+ bool update_slot = false;
+
Assert(MyReplicationSlot == NULL);
ReplicationSlotAcquire(name, false);
@@ -854,6 +856,20 @@ ReplicationSlotAlter(const char *name, bool failover)
MyReplicationSlot->data.failover = failover;
SpinLockRelease(&MyReplicationSlot->mutex);
+ update_slot = true;
+ }
+
+ if (MyReplicationSlot->data.two_phase != two_phase)
+ {
+ SpinLockAcquire(&MyReplicationSlot->mutex);
+ MyReplicationSlot->data.two_phase = two_phase;
+ SpinLockRelease(&MyReplicationSlot->mutex);
+
+ update_slot = true;
+ }
+
+ if (update_slot)
+ {
ReplicationSlotMarkDirty();
ReplicationSlotSave();
}
diff --git a/src/backend/replication/walsender.c b/src/backend/replication/walsender.c
index c623b07cf0..2e6ca35049 100644
--- a/src/backend/replication/walsender.c
+++ b/src/backend/replication/walsender.c
@@ -1411,9 +1411,11 @@ DropReplicationSlot(DropReplicationSlotCmd *cmd)
* Process extra options given to ALTER_REPLICATION_SLOT.
*/
static void
-ParseAlterReplSlotOptions(AlterReplicationSlotCmd *cmd, bool *failover)
+ParseAlterReplSlotOptions(AlterReplicationSlotCmd *cmd,
+ bool *failover, bool *two_phase)
{
bool failover_given = false;
+ bool two_phase_given = false;
/* Parse options */
foreach_ptr(DefElem, defel, cmd->options)
@@ -1427,6 +1429,15 @@ ParseAlterReplSlotOptions(AlterReplicationSlotCmd *cmd, bool *failover)
failover_given = true;
*failover = defGetBoolean(defel);
}
+ else if (strcmp(defel->defname, "two_phase") == 0)
+ {
+ if (two_phase_given)
+ ereport(ERROR,
+ (errcode(ERRCODE_SYNTAX_ERROR),
+ errmsg("conflicting or redundant options")));
+ two_phase_given = true;
+ *two_phase = defGetBoolean(defel);
+ }
else
elog(ERROR, "unrecognized option: %s", defel->defname);
}
@@ -1439,9 +1450,10 @@ static void
AlterReplicationSlot(AlterReplicationSlotCmd *cmd)
{
bool failover = false;
+ bool two_phase = false;
- ParseAlterReplSlotOptions(cmd, &failover);
- ReplicationSlotAlter(cmd->slotname, failover);
+ ParseAlterReplSlotOptions(cmd, &failover, &two_phase);
+ ReplicationSlotAlter(cmd->slotname, failover, two_phase);
}
/*
diff --git a/src/bin/psql/tab-complete.c b/src/bin/psql/tab-complete.c
index d453e224d9..891face1b6 100644
--- a/src/bin/psql/tab-complete.c
+++ b/src/bin/psql/tab-complete.c
@@ -1948,7 +1948,7 @@ psql_completion(const char *text, int start, int end)
else if (HeadMatches("ALTER", "SUBSCRIPTION", MatchAny) && TailMatches("SET", "("))
COMPLETE_WITH("binary", "disable_on_error", "failover", "origin",
"password_required", "run_as_owner", "slot_name",
- "streaming", "synchronous_commit");
+ "streaming", "synchronous_commit", "two_phase");
/* ALTER SUBSCRIPTION <name> SKIP ( */
else if (HeadMatches("ALTER", "SUBSCRIPTION", MatchAny) && TailMatches("SKIP", "("))
COMPLETE_WITH("lsn");
diff --git a/src/include/access/twophase.h b/src/include/access/twophase.h
index 56248c0006..d37e06fdee 100644
--- a/src/include/access/twophase.h
+++ b/src/include/access/twophase.h
@@ -62,4 +62,9 @@ extern void PrepareRedoRemove(TransactionId xid, bool giveWarning);
extern void restoreTwoPhaseData(void);
extern bool LookupGXact(const char *gid, XLogRecPtr prepare_end_lsn,
TimestampTz origin_prepare_timestamp);
+
+extern void TwoPhaseTransactionGid(Oid subid, TransactionId xid, char *gid,
+ int szgid);
+extern bool LookupGXactBySubid(Oid subid);
+
#endif /* TWOPHASE_H */
diff --git a/src/include/replication/slot.h b/src/include/replication/slot.h
index 1bc80960ef..014e216cf5 100644
--- a/src/include/replication/slot.h
+++ b/src/include/replication/slot.h
@@ -243,7 +243,8 @@ extern void ReplicationSlotCreate(const char *name, bool db_specific,
extern void ReplicationSlotPersist(void);
extern void ReplicationSlotDrop(const char *name, bool nowait);
extern void ReplicationSlotDropAcquired(void);
-extern void ReplicationSlotAlter(const char *name, bool failover);
+extern void ReplicationSlotAlter(const char *name, bool failover,
+ bool two_phase);
extern void ReplicationSlotAcquire(const char *name, bool nowait);
extern void ReplicationSlotRelease(void);
diff --git a/src/include/replication/walreceiver.h b/src/include/replication/walreceiver.h
index 12f71fa99b..31fa1257ec 100644
--- a/src/include/replication/walreceiver.h
+++ b/src/include/replication/walreceiver.h
@@ -372,12 +372,13 @@ typedef char *(*walrcv_create_slot_fn) (WalReceiverConn *conn,
/*
* walrcv_alter_slot_fn
*
- * Change the definition of a replication slot. Currently, it only supports
- * changing the failover property of the slot.
+ * Change the definition of a replication slot. Currently, it supports
+ * changing the failover and the two_phase property of the slot.
*/
typedef void (*walrcv_alter_slot_fn) (WalReceiverConn *conn,
const char *slotname,
- bool failover);
+ bool failover,
+ bool two_phase);
/*
* walrcv_get_backend_pid_fn
@@ -455,8 +456,8 @@ extern PGDLLIMPORT WalReceiverFunctionsType *WalReceiverFunctions;
WalReceiverFunctions->walrcv_send(conn, buffer, nbytes)
#define walrcv_create_slot(conn, slotname, temporary, two_phase, failover, snapshot_action, lsn) \
WalReceiverFunctions->walrcv_create_slot(conn, slotname, temporary, two_phase, failover, snapshot_action, lsn)
-#define walrcv_alter_slot(conn, slotname, failover) \
- WalReceiverFunctions->walrcv_alter_slot(conn, slotname, failover)
+#define walrcv_alter_slot(conn, slotname, failover, two_phase) \
+ WalReceiverFunctions->walrcv_alter_slot(conn, slotname, failover, two_phase)
#define walrcv_get_backend_pid(conn) \
WalReceiverFunctions->walrcv_get_backend_pid(conn)
#define walrcv_exec(conn, exec, nRetTypes, retTypes) \
diff --git a/src/include/replication/worker_internal.h b/src/include/replication/worker_internal.h
index 515aefd519..d5428263c1 100644
--- a/src/include/replication/worker_internal.h
+++ b/src/include/replication/worker_internal.h
@@ -246,6 +246,7 @@ extern bool logicalrep_worker_launch(LogicalRepWorkerType wtype,
Oid userid, Oid relid,
dsm_handle subworker_dsm);
extern void logicalrep_worker_stop(Oid subid, Oid relid);
+extern void logicalrep_workers_stop(Oid subid);
extern void logicalrep_pa_worker_stop(ParallelApplyWorkerInfo *winfo);
extern void logicalrep_worker_wakeup(Oid subid, Oid relid);
extern void logicalrep_worker_wakeup_ptr(LogicalRepWorker *worker);
diff --git a/src/test/regress/expected/subscription.out b/src/test/regress/expected/subscription.out
index 0f2a25cdc1..51fa4b9690 100644
--- a/src/test/regress/expected/subscription.out
+++ b/src/test/regress/expected/subscription.out
@@ -377,10 +377,7 @@ HINT: To initiate replication, you must manually create the replication slot, e
regress_testsub | regress_subscription_user | f | {testpub} | f | off | p | f | any | t | f | f | off | dbname=regress_doesnotexist | 0/0
(1 row)
---fail - alter of two_phase option not supported.
-ALTER SUBSCRIPTION regress_testsub SET (two_phase = false);
-ERROR: unrecognized subscription parameter: "two_phase"
--- but can alter streaming when two_phase enabled
+-- We can alter streaming when two_phase enabled
ALTER SUBSCRIPTION regress_testsub SET (streaming = true);
\dRs+
List of subscriptions
diff --git a/src/test/regress/sql/subscription.sql b/src/test/regress/sql/subscription.sql
index 3e5ba4cb8c..a3886d79ca 100644
--- a/src/test/regress/sql/subscription.sql
+++ b/src/test/regress/sql/subscription.sql
@@ -256,10 +256,7 @@ CREATE SUBSCRIPTION regress_testsub CONNECTION 'dbname=regress_doesnotexist' PUB
CREATE SUBSCRIPTION regress_testsub CONNECTION 'dbname=regress_doesnotexist' PUBLICATION testpub WITH (connect = false, two_phase = true);
\dRs+
---fail - alter of two_phase option not supported.
-ALTER SUBSCRIPTION regress_testsub SET (two_phase = false);
-
--- but can alter streaming when two_phase enabled
+-- We can alter streaming when two_phase enabled
ALTER SUBSCRIPTION regress_testsub SET (streaming = true);
\dRs+
diff --git a/src/test/subscription/t/021_twophase.pl b/src/test/subscription/t/021_twophase.pl
index 9437cd4c3b..72df258000 100644
--- a/src/test/subscription/t/021_twophase.pl
+++ b/src/test/subscription/t/021_twophase.pl
@@ -367,6 +367,75 @@ $result =
$node_subscriber->safe_psql('postgres', "SELECT count(*) FROM tab_copy;");
is($result, qq(2), 'replicated data in subscriber table');
+# Clean up
+$node_subscriber->safe_psql('postgres', "DROP SUBSCRIPTION tap_sub");
+
+###############################
+# Disable the subscription and alter it to two_phase = false,
+# then verify that the altered subscription reflects the two_phase option.
+###############################
+
+# Alter subscription two_phase to false
+$node_subscriber->safe_psql('postgres',
+ "ALTER SUBSCRIPTION tap_sub_copy DISABLE");
+$node_subscriber->safe_psql('postgres',
+ "ALTER SUBSCRIPTION tap_sub_copy SET (two_phase = false)");
+$node_subscriber->safe_psql('postgres',
+ "ALTER SUBSCRIPTION tap_sub_copy ENABLE");
+
+# Wait for subscription startup
+$node_subscriber->wait_for_subscription_sync($node_publisher, $appname_copy);
+
+# Make sure that the two-phase is disabled on the subscriber
+$result = $node_subscriber->safe_psql('postgres',
+ "SELECT subtwophasestate FROM pg_subscription WHERE subname = 'tap_sub_copy';"
+);
+is($result, qq(d), 'two-phase should be disabled');
+
+# Now do a prepare on the publisher and make sure that it is not replicated.
+$node_publisher->safe_psql(
+ 'postgres', qq{
+ BEGIN;
+ INSERT INTO tab_copy VALUES (100);
+ PREPARE TRANSACTION 'newgid';
+ });
+
+# Wait for the subscriber to catchup
+$node_publisher->wait_for_catchup($appname_copy);
+
+# Make sure there are no prepared transactions on the subscriber
+$result = $node_subscriber->safe_psql('postgres',
+ "SELECT count(*) FROM pg_prepared_xacts;");
+is($result, qq(0), 'should be no prepared transactions on subscriber');
+
+# Now commit the insert and verify that it IS replicated
+$node_publisher->safe_psql('postgres', "COMMIT PREPARED 'newgid';");
+
+# Wait for the subscriber to catchup
+$node_publisher->wait_for_catchup($appname_copy);
+
+# Make sure that the committed transaction is replicated.
+$result =
+ $node_subscriber->safe_psql('postgres', "SELECT count(*) FROM tab_copy;");
+is($result, qq(3), 'replicated data in subscriber table');
+
+# Alter subscription two_phase to true
+$node_subscriber->safe_psql('postgres',
+ "ALTER SUBSCRIPTION tap_sub_copy DISABLE");
+$node_subscriber->safe_psql('postgres',
+ "ALTER SUBSCRIPTION tap_sub_copy SET (two_phase = true)");
+$node_subscriber->safe_psql('postgres',
+ "ALTER SUBSCRIPTION tap_sub_copy ENABLE");
+
+# Wait for subscription startup
+$node_subscriber->wait_for_subscription_sync($node_publisher, $appname_copy);
+
+# Make sure that the two-phase is enabled on the subscriber
+$result = $node_subscriber->safe_psql('postgres',
+ "SELECT subtwophasestate FROM pg_subscription WHERE subname = 'tap_sub_copy';"
+);
+is($result, qq(e), 'two-phase should be enabled');
+
$node_subscriber->safe_psql('postgres', "DROP SUBSCRIPTION tap_sub_copy;");
$node_publisher->safe_psql('postgres', "DROP PUBLICATION tap_pub_copy;");
@@ -374,8 +443,6 @@ $node_publisher->safe_psql('postgres', "DROP PUBLICATION tap_pub_copy;");
# check all the cleanup
###############################
-$node_subscriber->safe_psql('postgres', "DROP SUBSCRIPTION tap_sub");
-
$result = $node_subscriber->safe_psql('postgres',
"SELECT count(*) FROM pg_subscription");
is($result, qq(0), 'check subscription was dropped on subscriber');
--
2.43.0
[application/octet-stream] v8-0002-Alter-slot-option-two_phase-only-when-altering-on.patch (11.0K, ../../OSBPR01MB2552F738ACF1DA6838025C4FF5E62@OSBPR01MB2552.jpnprd01.prod.outlook.com/3-v8-0002-Alter-slot-option-two_phase-only-when-altering-on.patch)
download | inline diff:
From b3853307efcdbee2c9053688b3860f0b2347462b Mon Sep 17 00:00:00 2001
From: Hayato Kuroda <[email protected]>
Date: Wed, 17 Apr 2024 06:18:23 +0000
Subject: [PATCH v8 2/4] Alter slot option two_phase only when altering "on" to
"off"
Since the two_phase option is controlled by both the publisher (as a slot option)
and the subscriber (as a subscription option), the slot option must also be
modified.
Regarding the off->on case, the logical replication already has a mechanism for
it, so there is no need to do anything special for the on->off case; however,
we must connect to the publisher and expressly change the parameter. The
operation cannot be rolled back, and altering the parameter from "on" to "off"
within a transaction is prohibited.
---
doc/src/sgml/ref/alter_subscription.sgml | 2 +-
src/backend/commands/subscriptioncmds.c | 30 ++++--
.../libpqwalreceiver/libpqwalreceiver.c | 23 +++--
src/include/replication/walreceiver.h | 5 +-
src/test/subscription/meson.build | 1 +
src/test/subscription/t/099_twophase_added.pl | 95 +++++++++++++++++++
6 files changed, 140 insertions(+), 16 deletions(-)
create mode 100644 src/test/subscription/t/099_twophase_added.pl
diff --git a/doc/src/sgml/ref/alter_subscription.sgml b/doc/src/sgml/ref/alter_subscription.sgml
index 88e9a72147..0c2894a94e 100644
--- a/doc/src/sgml/ref/alter_subscription.sgml
+++ b/doc/src/sgml/ref/alter_subscription.sgml
@@ -70,7 +70,7 @@ ALTER SUBSCRIPTION <replaceable class="parameter">name</replaceable> RENAME TO <
<command>ALTER SUBSCRIPTION ... {SET|ADD|DROP} PUBLICATION ...</command>
with <literal>refresh</literal> option as <literal>true</literal>,
<command>ALTER SUBSCRIPTION ... SET (failover = on|off)</command> and
- <command>ALTER SUBSCRIPTION ... SET (two_phase = on|off)</command>
+ <command>ALTER SUBSCRIPTION ... SET (two_phase = off)</command>
cannot be executed inside a transaction block.
These commands also cannot be executed when the subscription has
diff --git a/src/backend/commands/subscriptioncmds.c b/src/backend/commands/subscriptioncmds.c
index 90d967eb7c..6b2cb71dac 100644
--- a/src/backend/commands/subscriptioncmds.c
+++ b/src/backend/commands/subscriptioncmds.c
@@ -1097,6 +1097,8 @@ AlterSubscription(ParseState *pstate, AlterSubscriptionStmt *stmt,
Form_pg_subscription form;
bits32 supported_opts;
SubOpts opts = {0};
+ bool update_failover;
+ bool update_two_phase;
rel = table_open(SubscriptionRelationId, RowExclusiveLock);
@@ -1186,10 +1188,14 @@ AlterSubscription(ParseState *pstate, AlterSubscriptionStmt *stmt,
errhint("Resolve these transactions and try again")));
/*
- * The changed two_phase option of the slot can't be rolled
- * back.
+ * Since the altering two_phase option of subscriptions
+ * also leads to the change of slot option, this command
+ * cannot be rolled back. So prevent we are in the
+ * transaction block.
*/
- PreventInTransactionBlock(isTopLevel, "ALTER SUBSCRIPTION ... SET (two_phase)");
+ if (!opts.twophase)
+ PreventInTransactionBlock(isTopLevel,
+ "ALTER SUBSCRIPTION ... SET (two_phase = off)");
/* Change system catalog acoordingly */
values[Anum_pg_subscription_subtwophasestate - 1] =
@@ -1547,14 +1553,22 @@ AlterSubscription(ParseState *pstate, AlterSubscriptionStmt *stmt,
}
/*
- * Try to acquire the connection necessary for altering slot.
+ * Check the need to alter the replication slot. Failover and two_phase
+ * options are controlled by both the publisher (as a slot option) and the
+ * subscriber (as a subscription option).
+ */
+ update_failover = replaces[Anum_pg_subscription_subfailover - 1];
+ update_two_phase = (replaces[Anum_pg_subscription_subtwophasestate - 1] &&
+ !opts.twophase);
+
+ /*
+ * Try to acquire the connection necessary for altering slot, if needed.
*
* This has to be at the end because otherwise if there is an error while
* doing the database operations we won't be able to rollback altered
* slot.
*/
- if (replaces[Anum_pg_subscription_subfailover - 1] ||
- replaces[Anum_pg_subscription_subtwophasestate - 1])
+ if (update_failover || update_two_phase)
{
bool must_use_password;
char *err;
@@ -1574,7 +1588,9 @@ AlterSubscription(ParseState *pstate, AlterSubscriptionStmt *stmt,
PG_TRY();
{
- walrcv_alter_slot(wrconn, sub->slotname, opts.failover, opts.twophase);
+ walrcv_alter_slot(wrconn, sub->slotname,
+ update_failover ? &opts.failover : NULL,
+ update_two_phase ? &opts.twophase : NULL);
}
PG_FINALLY();
{
diff --git a/src/backend/replication/libpqwalreceiver/libpqwalreceiver.c b/src/backend/replication/libpqwalreceiver/libpqwalreceiver.c
index 998bbd517a..2800597f4c 100644
--- a/src/backend/replication/libpqwalreceiver/libpqwalreceiver.c
+++ b/src/backend/replication/libpqwalreceiver/libpqwalreceiver.c
@@ -80,7 +80,7 @@ static char *libpqrcv_create_slot(WalReceiverConn *conn,
CRSSnapshotAction snapshot_action,
XLogRecPtr *lsn);
static void libpqrcv_alter_slot(WalReceiverConn *conn, const char *slotname,
- bool failover, bool two_phase);
+ const bool *failover, const bool *two_phase);
static pid_t libpqrcv_get_backend_pid(WalReceiverConn *conn);
static WalRcvExecResult *libpqrcv_exec(WalReceiverConn *conn,
const char *query,
@@ -1121,16 +1121,27 @@ libpqrcv_create_slot(WalReceiverConn *conn, const char *slotname,
*/
static void
libpqrcv_alter_slot(WalReceiverConn *conn, const char *slotname,
- bool failover, bool two_phase)
+ const bool *failover, const bool *two_phase)
{
StringInfoData cmd;
PGresult *res;
initStringInfo(&cmd);
- appendStringInfo(&cmd, "ALTER_REPLICATION_SLOT %s ( FAILOVER %s, TWO_PHASE %s )",
- quote_identifier(slotname),
- failover ? "true" : "false",
- two_phase ? "true" : "false");
+ appendStringInfo(&cmd, "ALTER_REPLICATION_SLOT %s ( ",
+ quote_identifier(slotname));
+
+ if (failover)
+ appendStringInfo(&cmd, "FAILOVER %s",
+ *failover ? "true" : "false");
+
+ if (failover && two_phase)
+ appendStringInfo(&cmd, ", ");
+
+ if (two_phase)
+ appendStringInfo(&cmd, "TWO_PHASE %s",
+ *two_phase ? "true" : "false");
+
+ appendStringInfoString(&cmd, ");");
res = libpqrcv_PQexec(conn->streamConn, cmd.data);
pfree(cmd.data);
diff --git a/src/include/replication/walreceiver.h b/src/include/replication/walreceiver.h
index 31fa1257ec..7ffa5a58b3 100644
--- a/src/include/replication/walreceiver.h
+++ b/src/include/replication/walreceiver.h
@@ -377,8 +377,9 @@ typedef char *(*walrcv_create_slot_fn) (WalReceiverConn *conn,
*/
typedef void (*walrcv_alter_slot_fn) (WalReceiverConn *conn,
const char *slotname,
- bool failover,
- bool two_phase);
+ const bool *failover,
+ const bool *two_phase);
+
/*
* walrcv_get_backend_pid_fn
diff --git a/src/test/subscription/meson.build b/src/test/subscription/meson.build
index c591cd7d61..b4bd522c3d 100644
--- a/src/test/subscription/meson.build
+++ b/src/test/subscription/meson.build
@@ -40,6 +40,7 @@ tests += {
't/031_column_list.pl',
't/032_subscribe_use_index.pl',
't/033_run_as_table_owner.pl',
+ 't/099_twophase_added.pl',
't/100_bugs.pl',
],
},
diff --git a/src/test/subscription/t/099_twophase_added.pl b/src/test/subscription/t/099_twophase_added.pl
new file mode 100644
index 0000000000..62f4acad27
--- /dev/null
+++ b/src/test/subscription/t/099_twophase_added.pl
@@ -0,0 +1,95 @@
+# Copyright (c) 2024, PostgreSQL Global Development Group
+
+# Additional tests for altering two_phase option
+use strict;
+use warnings FATAL => 'all';
+use PostgreSQL::Test::Cluster;
+use PostgreSQL::Test::Utils;
+use Test::More;
+
+# Initialize publisher node
+my $node_publisher = PostgreSQL::Test::Cluster->new('publisher');
+$node_publisher->init(allows_streaming => 'logical');
+$node_publisher->append_conf('postgresql.conf',
+ qq(max_prepared_transactions = 10));
+$node_publisher->start;
+
+# Create subscriber node
+my $node_subscriber = PostgreSQL::Test::Cluster->new('subscriber');
+$node_subscriber->init;
+$node_subscriber->append_conf('postgresql.conf',
+ qq(max_prepared_transactions = 10
+ log_min_messages = debug1));
+$node_subscriber->start;
+
+# Define tables on both nodes
+$node_publisher->safe_psql('postgres',
+ "CREATE TABLE tab_full (a int PRIMARY KEY);");
+$node_subscriber->safe_psql('postgres',
+ "CREATE TABLE tab_full (a int PRIMARY KEY)");
+
+# Setup logical replication, with two_phase = "off"
+my $publisher_connstr = $node_publisher->connstr . ' dbname=postgres';
+$node_publisher->safe_psql('postgres',
+ "CREATE PUBLICATION pub FOR ALL TABLES");
+
+my $log_offset = -s $node_subscriber->logfile;
+
+$node_subscriber->safe_psql(
+ 'postgres', "
+ CREATE SUBSCRIPTION regress_sub
+ CONNECTION '$publisher_connstr' PUBLICATION pub
+ WITH (two_phase = off, copy_data = off, failover = off)");
+
+# Verify the started worker recognized two_phase was disabled
+$node_subscriber->wait_for_log(
+ 'logical replication apply worker for subscription "regress_sub" two_phase is DISABLED', $log_offset);
+
+# Check the case that prepared transactions exist on the publisher node.
+#
+# Since the two_phase is "off", then normally, this PREPARE will do nothing
+# until the COMMIT PREPARED, but in this test, we toggle the two_phase to "on"
+# again before the COMMIT PREPARED happens.
+
+# Prepare a transaction to insert some tuples into the table
+$node_publisher->safe_psql(
+ 'postgres', "
+ BEGIN;
+ INSERT INTO tab_full VALUES (generate_series(1, 5));
+ PREPARE TRANSACTION 'test_prepared_tab_full';");
+
+$node_publisher->wait_for_catchup('regress_sub');
+
+# Verify the prepared transaction is not yet replicated to the subscriber
+# because two_phase is set to "off".
+my $result = $node_subscriber->safe_psql('postgres',
+ "SELECT count(*) FROM pg_prepared_xacts;");
+is($result, q(0), "transaction is not prepared on subscriber");
+
+$log_offset = -s $node_subscriber->logfile;
+
+# Toggle the two_phase to "on" *before* the COMMIT PREPARED. Since we are the
+# special path for the case where both two_phase and failover are altered, it
+# is also set to "on".
+$node_subscriber->safe_psql(
+ 'postgres', "
+ ALTER SUBSCRIPTION regress_sub DISABLE;
+ ALTER SUBSCRIPTION regress_sub SET (two_phase = on, failover = on);
+ ALTER SUBSCRIPTION regress_sub ENABLE;");
+
+# Verify the started worker recognized two_phase was enabled
+$node_subscriber->wait_for_log(
+ 'logical replication apply worker for subscription "regress_sub" two_phase is ENABLED', $log_offset);
+
+# And do COMMIT PREPARED the prepared transaction
+$node_publisher->safe_psql('postgres',
+ "COMMIT PREPARED 'test_prepared_tab_full';");
+$node_publisher->wait_for_catchup('regress_sub');
+
+# Verify inserted tuples are replicated
+$result = $node_subscriber->safe_psql('postgres',
+ "SELECT count(*) FROM tab_full;");
+is($result, q(5),
+ "prepared transactions done before altering can be replicated");
+
+done_testing();
--
2.43.0
[application/octet-stream] v8-0003-Abort-prepared-transactions-while-altering-two_ph.patch (8.2K, ../../OSBPR01MB2552F738ACF1DA6838025C4FF5E62@OSBPR01MB2552.jpnprd01.prod.outlook.com/4-v8-0003-Abort-prepared-transactions-while-altering-two_ph.patch)
download | inline diff:
From d4d4503ea12bfd23325e78c8f2b75016f4c163c7 Mon Sep 17 00:00:00 2001
From: Hayato Kuroda <[email protected]>
Date: Mon, 8 Apr 2024 12:39:12 +0000
Subject: [PATCH v8 3/4] Abort prepared transactions while altering two_phase
to off
If we alter the two_phase parameter from "on" to "off" and there are prepared
transactions on the subscriber, they won't be resolved. To avoid this issue, we
allow the backend to abort all prepared transactions while altering the
subscription.
---
doc/src/sgml/ref/alter_subscription.sgml | 9 +++-
src/backend/access/transam/twophase.c | 17 +++----
src/backend/commands/subscriptioncmds.c | 43 +++++++++++-------
src/include/access/twophase.h | 3 +-
src/test/subscription/t/099_twophase_added.pl | 44 +++++++++++++++++++
5 files changed, 87 insertions(+), 29 deletions(-)
diff --git a/doc/src/sgml/ref/alter_subscription.sgml b/doc/src/sgml/ref/alter_subscription.sgml
index 0c2894a94e..e81661aa04 100644
--- a/doc/src/sgml/ref/alter_subscription.sgml
+++ b/doc/src/sgml/ref/alter_subscription.sgml
@@ -233,8 +233,6 @@ ALTER SUBSCRIPTION <replaceable class="parameter">name</replaceable> RENAME TO <
<link linkend="sql-createsubscription-params-with-failover"><literal>failover</literal></link>, and
<link linkend="sql-createsubscription-params-with-two-phase"><literal>two_phase</literal></link>.
Only a superuser can set <literal>password_required = false</literal>.
- The <literal>two_phase</literal> parameter can only be altered when the
- subscription is disabled.
</para>
<para>
@@ -256,6 +254,13 @@ ALTER SUBSCRIPTION <replaceable class="parameter">name</replaceable> RENAME TO <
<link linkend="sql-createsubscription-params-with-failover"><literal>failover</literal></link>
option is enabled.
</para>
+
+ <para>
+ The <literal>two_phase</literal> parameter can only be altered when the
+ subscription is disabled. When altering the parameter from <literal>on</literal>
+ to <literal>off</literal>, the backend process checks prepared
+ transactions done by the logical replication worker and aborts them.
+ </para>
</listitem>
</varlistentry>
diff --git a/src/backend/access/transam/twophase.c b/src/backend/access/transam/twophase.c
index 66fa591eb5..f384bd8c0a 100644
--- a/src/backend/access/transam/twophase.c
+++ b/src/backend/access/transam/twophase.c
@@ -2720,13 +2720,13 @@ IsTwoPhaseTransactionGidForSubid(Oid subid, char *gid)
}
/*
- * LookupGXactBySubid
- * Check if the prepared transaction done by apply worker exists.
+ * GetGidListBySubid
+ * Get a list of GIDs which is PREPARE'd by the given subscription.
*/
-bool
-LookupGXactBySubid(Oid subid)
+List *
+GetGidListBySubid(Oid subid)
{
- bool found = false;
+ List *list = NIL;
LWLockAcquire(TwoPhaseStateLock, LW_SHARED);
for (int i = 0; i < TwoPhaseState->numPrepXacts; i++)
@@ -2736,11 +2736,8 @@ LookupGXactBySubid(Oid subid)
/* Ignore not-yet-valid GIDs. */
if (gxact->valid &&
IsTwoPhaseTransactionGidForSubid(subid, gxact->gid))
- {
- found = true;
- break;
- }
+ list = lappend(list, pstrdup(gxact->gid));
}
LWLockRelease(TwoPhaseStateLock);
- return found;
+ return list;
}
diff --git a/src/backend/commands/subscriptioncmds.c b/src/backend/commands/subscriptioncmds.c
index 6b2cb71dac..cabbf9eab9 100644
--- a/src/backend/commands/subscriptioncmds.c
+++ b/src/backend/commands/subscriptioncmds.c
@@ -1176,27 +1176,38 @@ AlterSubscription(ParseState *pstate, AlterSubscriptionStmt *stmt,
logicalrep_workers_stop(subid);
/*
- * two_phase cannot be disabled if there are any
- * uncommitted prepared transactions present.
- */
- if (!opts.twophase &&
- form->subtwophasestate == LOGICALREP_TWOPHASE_STATE_ENABLED &&
- LookupGXactBySubid(subid))
- ereport(ERROR,
- (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
- errmsg("cannot disable two_phase when uncommitted prepared transactions present"),
- errhint("Resolve these transactions and try again")));
-
- /*
- * Since the altering two_phase option of subscriptions
- * also leads to the change of slot option, this command
- * cannot be rolled back. So prevent we are in the
- * transaction block.
+ * If two_phase was enabled, there is a possibility the
+ * transactions has already been PREPARE'd. They must be
+ * checked and rolled back.
*/
if (!opts.twophase)
+ {
+ List *prepared_xacts;
+
+ /*
+ * Since the altering two_phase option of subscriptions
+ * (especially on->off case) also leads to the
+ * change of slot option, this command cannot be rolled
+ * back. So prevent we are in the transaction block.
+ */
PreventInTransactionBlock(isTopLevel,
"ALTER SUBSCRIPTION ... SET (two_phase = off)");
+ /*
+ * To prevent prepared transactions from being
+ * isolated, they must manually be aborted.
+ */
+ if (sub->twophasestate == LOGICALREP_TWOPHASE_STATE_ENABLED &&
+ (prepared_xacts = GetGidListBySubid(subid)) != NIL)
+ {
+ /* Abort all listed transactions */
+ foreach_ptr(char, gid, prepared_xacts)
+ FinishPreparedTransaction(gid, false);
+
+ list_free_deep(prepared_xacts);
+ }
+ }
+
/* Change system catalog acoordingly */
values[Anum_pg_subscription_subtwophasestate - 1] =
CharGetDatum(opts.twophase ?
diff --git a/src/include/access/twophase.h b/src/include/access/twophase.h
index d37e06fdee..f7a5cf0c12 100644
--- a/src/include/access/twophase.h
+++ b/src/include/access/twophase.h
@@ -18,6 +18,7 @@
#include "access/xlogdefs.h"
#include "datatype/timestamp.h"
#include "storage/lock.h"
+#include "nodes/pg_list.h"
/*
* GlobalTransactionData is defined in twophase.c; other places have no
@@ -65,6 +66,6 @@ extern bool LookupGXact(const char *gid, XLogRecPtr prepare_end_lsn,
extern void TwoPhaseTransactionGid(Oid subid, TransactionId xid, char *gid,
int szgid);
-extern bool LookupGXactBySubid(Oid subid);
+extern List *GetGidListBySubid(Oid subid);
#endif /* TWOPHASE_H */
diff --git a/src/test/subscription/t/099_twophase_added.pl b/src/test/subscription/t/099_twophase_added.pl
index 62f4acad27..59baa3eadc 100644
--- a/src/test/subscription/t/099_twophase_added.pl
+++ b/src/test/subscription/t/099_twophase_added.pl
@@ -92,4 +92,48 @@ $result = $node_subscriber->safe_psql('postgres',
is($result, q(5),
"prepared transactions done before altering can be replicated");
+# Check the case that prepared transactions exist on the subscriber node
+#
+# If the two_phase is altering from "on" to "off" and there are prepared
+# transactions on the subscriber, they must be aborted. This test checks it.
+
+# Prepare a transaction to insert some tuples into the table
+$node_publisher->safe_psql(
+ 'postgres', "
+ BEGIN;
+ INSERT INTO tab_full VALUES (generate_series(6, 10));
+ PREPARE TRANSACTION 'test_prepared_tab_full';");
+
+$node_publisher->wait_for_catchup('regress_sub');
+
+# Verify the prepared transaction has been replicated to the subscriber because
+# two_phase is set to "on".
+$result = $node_subscriber->safe_psql('postgres',
+ "SELECT count(*) FROM pg_prepared_xacts;");
+is($result, q(1), "transaction has been prepared on subscriber");
+
+# Toggle the two_phase to "off" before the COMMIT PREPARED
+$node_subscriber->safe_psql(
+ 'postgres', "
+ ALTER SUBSCRIPTION regress_sub DISABLE;
+ ALTER SUBSCRIPTION regress_sub SET (two_phase = off);
+ ALTER SUBSCRIPTION regress_sub ENABLE;");
+
+# Verify the prepared transaction are aborted because two_phase is changed to
+# "off".
+$result = $node_subscriber->safe_psql('postgres',
+ "SELECT count(*) FROM pg_prepared_xacts;");
+is($result, q(0), "prepared transaction done by worker is aborted");
+
+# Do COMMIT PREPARED the prepared transaction
+$node_publisher->safe_psql( 'postgres',
+ "COMMIT PREPARED 'test_prepared_tab_full';");
+$node_publisher->wait_for_catchup('regress_sub');
+
+# Verify inserted tuples are replicated
+$result = $node_subscriber->safe_psql('postgres',
+ "SELECT count(10) FROM tab_full;");
+is($result, q(10),
+ "prepared transactions on publisher can be replicated");
+
done_testing();
--
2.43.0
[application/octet-stream] v8-0004-Add-force_alter-option-for-ALTER-SUBSCIRPTION-.-S.patch (9.5K, ../../OSBPR01MB2552F738ACF1DA6838025C4FF5E62@OSBPR01MB2552.jpnprd01.prod.outlook.com/5-v8-0004-Add-force_alter-option-for-ALTER-SUBSCIRPTION-.-S.patch)
download | inline diff:
From 0ed818f49046ec06c5d2f56928fd1a672892c6b8 Mon Sep 17 00:00:00 2001
From: Hayato Kuroda <[email protected]>
Date: Fri, 19 Apr 2024 11:03:19 +0000
Subject: [PATCH v8 4/4] Add force_alter option for ALTER SUBSCIRPTION ... SET
command
Previously, all prepared transactions on the standby were rolled back when
toggling two_phase from "on" to "off". However, this operation may not be
expected by users. To ensure users understand what happens, we added the
"force_alter" parameter. When two_phase is toggling to "off", and there are
prepared transactions, they will be aborted only when "force_alter" is set to
true. Otherwise, an ERROR occurs.
---
doc/src/sgml/ref/alter_subscription.sgml | 9 ++--
src/backend/commands/subscriptioncmds.c | 28 ++++++++++++-
src/test/regress/expected/subscription.out | 3 ++
src/test/regress/sql/subscription.sql | 3 ++
src/test/subscription/t/099_twophase_added.pl | 42 +++++++++++++++----
5 files changed, 72 insertions(+), 13 deletions(-)
diff --git a/doc/src/sgml/ref/alter_subscription.sgml b/doc/src/sgml/ref/alter_subscription.sgml
index e81661aa04..1324d6390a 100644
--- a/doc/src/sgml/ref/alter_subscription.sgml
+++ b/doc/src/sgml/ref/alter_subscription.sgml
@@ -257,9 +257,12 @@ ALTER SUBSCRIPTION <replaceable class="parameter">name</replaceable> RENAME TO <
<para>
The <literal>two_phase</literal> parameter can only be altered when the
- subscription is disabled. When altering the parameter from <literal>on</literal>
- to <literal>off</literal>, the backend process checks prepared
- transactions done by the logical replication worker and aborts them.
+ subscription is disabled. Altering the parameter from <literal>on</literal>
+ to <literal>off</literal> will be failed when there are prepared
+ transactions done by the logical replication worker. If you want to alter
+ the parameter forcibly in this case, <literal>force_alter</literal>
+ option must be set to <literal>on</literal> at the same time. If
+ specified, the backend process aborts prepared transactions.
</para>
</listitem>
</varlistentry>
diff --git a/src/backend/commands/subscriptioncmds.c b/src/backend/commands/subscriptioncmds.c
index cabbf9eab9..8b4ea403a0 100644
--- a/src/backend/commands/subscriptioncmds.c
+++ b/src/backend/commands/subscriptioncmds.c
@@ -73,6 +73,7 @@
#define SUBOPT_FAILOVER 0x00002000
#define SUBOPT_LSN 0x00004000
#define SUBOPT_ORIGIN 0x00008000
+#define SUBOPT_FORCE_ALTER 0x00010000
/* check if the 'val' has 'bits' set */
#define IsSet(val, bits) (((val) & (bits)) == (bits))
@@ -100,6 +101,7 @@ typedef struct SubOpts
bool failover;
char *origin;
XLogRecPtr lsn;
+ bool force_alter;
} SubOpts;
static List *fetch_table_list(WalReceiverConn *wrconn, List *publications);
@@ -162,6 +164,8 @@ parse_subscription_options(ParseState *pstate, List *stmt_options,
opts->failover = false;
if (IsSet(supported_opts, SUBOPT_ORIGIN))
opts->origin = pstrdup(LOGICALREP_ORIGIN_ANY);
+ if (IsSet(supported_opts, SUBOPT_FORCE_ALTER))
+ opts->force_alter = false;
/* Parse options */
foreach(lc, stmt_options)
@@ -367,6 +371,15 @@ parse_subscription_options(ParseState *pstate, List *stmt_options,
opts->specified_opts |= SUBOPT_LSN;
opts->lsn = lsn;
}
+ else if (IsSet(supported_opts, SUBOPT_FORCE_ALTER) &&
+ strcmp(defel->defname, "force_alter") == 0)
+ {
+ if (IsSet(opts->specified_opts, SUBOPT_FORCE_ALTER))
+ errorConflictingDefElem(defel, pstate);
+
+ opts->specified_opts |= SUBOPT_FORCE_ALTER;
+ opts->force_alter = defGetBoolean(defel);
+ }
else
ereport(ERROR,
(errcode(ERRCODE_SYNTAX_ERROR),
@@ -1150,7 +1163,7 @@ AlterSubscription(ParseState *pstate, AlterSubscriptionStmt *stmt,
SUBOPT_DISABLE_ON_ERR |
SUBOPT_PASSWORD_REQUIRED |
SUBOPT_RUN_AS_OWNER | SUBOPT_FAILOVER |
- SUBOPT_ORIGIN);
+ SUBOPT_ORIGIN | SUBOPT_FORCE_ALTER);
parse_subscription_options(pstate, stmt->options,
supported_opts, &opts);
@@ -1200,6 +1213,19 @@ AlterSubscription(ParseState *pstate, AlterSubscriptionStmt *stmt,
if (sub->twophasestate == LOGICALREP_TWOPHASE_STATE_ENABLED &&
(prepared_xacts = GetGidListBySubid(subid)) != NIL)
{
+ /*
+ * Abort prepared transactions only if
+ * 'force_alter' option is true. Otherwise raise
+ * an ERROR.
+ */
+ if (!opts.force_alter)
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("cannot alter %s when there are prepared transactions",
+ "two_phase = off"),
+ errhint("Resolve these transactions or set %s at the same time, and then try again.",
+ "force_alter = true")));
+
/* Abort all listed transactions */
foreach_ptr(char, gid, prepared_xacts)
FinishPreparedTransaction(gid, false);
diff --git a/src/test/regress/expected/subscription.out b/src/test/regress/expected/subscription.out
index 51fa4b9690..f607045b28 100644
--- a/src/test/regress/expected/subscription.out
+++ b/src/test/regress/expected/subscription.out
@@ -370,6 +370,9 @@ ERROR: two_phase requires a Boolean value
CREATE SUBSCRIPTION regress_testsub CONNECTION 'dbname=regress_doesnotexist' PUBLICATION testpub WITH (connect = false, two_phase = true);
WARNING: subscription was created, but is not connected
HINT: To initiate replication, you must manually create the replication slot, enable the subscription, and refresh the subscription.
+-- fail - force_alter cannot be set alone
+ALTER SUBSCRIPTION regress_testsub SET (force_alter = true);
+ERROR: force_alter must be specified with two_phase
\dRs+
List of subscriptions
Name | Owner | Enabled | Publication | Binary | Streaming | Two-phase commit | Disable on error | Origin | Password required | Run as owner? | Failover | Synchronous commit | Conninfo | Skip LSN
diff --git a/src/test/regress/sql/subscription.sql b/src/test/regress/sql/subscription.sql
index a3886d79ca..80ab4dd9bc 100644
--- a/src/test/regress/sql/subscription.sql
+++ b/src/test/regress/sql/subscription.sql
@@ -255,6 +255,9 @@ CREATE SUBSCRIPTION regress_testsub CONNECTION 'dbname=regress_doesnotexist' PUB
-- now it works
CREATE SUBSCRIPTION regress_testsub CONNECTION 'dbname=regress_doesnotexist' PUBLICATION testpub WITH (connect = false, two_phase = true);
+-- fail - force_alter cannot be set alone
+ALTER SUBSCRIPTION regress_testsub SET (force_alter = true);
+
\dRs+
-- We can alter streaming when two_phase enabled
ALTER SUBSCRIPTION regress_testsub SET (streaming = true);
diff --git a/src/test/subscription/t/099_twophase_added.pl b/src/test/subscription/t/099_twophase_added.pl
index 59baa3eadc..c826881802 100644
--- a/src/test/subscription/t/099_twophase_added.pl
+++ b/src/test/subscription/t/099_twophase_added.pl
@@ -95,7 +95,8 @@ is($result, q(5),
# Check the case that prepared transactions exist on the subscriber node
#
# If the two_phase is altering from "on" to "off" and there are prepared
-# transactions on the subscriber, they must be aborted. This test checks it.
+# transactions on the subscriber, we must error out or abort all prepared
+# transactions. Below part checks both cases.
# Prepare a transaction to insert some tuples into the table
$node_publisher->safe_psql(
@@ -112,15 +113,38 @@ $result = $node_subscriber->safe_psql('postgres',
"SELECT count(*) FROM pg_prepared_xacts;");
is($result, q(1), "transaction has been prepared on subscriber");
-# Toggle the two_phase to "off" before the COMMIT PREPARED
-$node_subscriber->safe_psql(
- 'postgres', "
- ALTER SUBSCRIPTION regress_sub DISABLE;
- ALTER SUBSCRIPTION regress_sub SET (two_phase = off);
- ALTER SUBSCRIPTION regress_sub ENABLE;");
-# Verify the prepared transaction are aborted because two_phase is changed to
-# "off".
+# Disable the subscription to alter the two_phase option
+$node_subscriber->safe_psql('postgres', "ALTER SUBSCRIPTION regress_sub DISABLE;");
+
+# Try altering the two_phase option to "off." The command will fail since there
+# is a prepared transaction and the force option is not specified.
+my $stdout;
+my $stderr;
+
+($result, $stdout, $stderr) = $node_subscriber->psql(
+ 'postgres', "ALTER SUBSCRIPTION regress_sub SET (two_phase = off);");
+ok($stderr =~ /cannot alter two_phase = off when there are prepared transactions/,
+ 'ALTER SUBSCRIPTION failed');
+
+# Verify the prepared transaction still exists
+$result = $node_subscriber->safe_psql('postgres',
+ "SELECT count(*) FROM pg_prepared_xacts;");
+is($result, q(1), "prepared transaction still exits");
+
+$log_offset = -s $node_subscriber->logfile;
+
+# Alter the two_phase with the force_alter option. Apart from the above, the
+# command will abort the prepared transaction and succeed.
+$node_subscriber->safe_psql('postgres',
+ "ALTER SUBSCRIPTION regress_sub SET (two_phase = off, force_alter = true);");
+$node_subscriber->safe_psql('postgres', "ALTER SUBSCRIPTION regress_sub ENABLE;");
+
+# Verify the started worker recognized two_phase was disabled
+$node_subscriber->wait_for_log(
+ 'logical replication apply worker for subscription "regress_sub" two_phase is DISABLED', $log_offset);
+
+# Verify the prepared transaction are aborted
$result = $node_subscriber->safe_psql('postgres',
"SELECT count(*) FROM pg_prepared_xacts;");
is($result, q(0), "prepared transaction done by worker is aborted");
--
2.43.0
^ permalink raw reply [nested|flat] 25+ messages in thread
* Re: Slow catchup of 2PC (twophase) transactions on replica in LR
@ 2024-05-13 06:34 Peter Smith <[email protected]>
parent: Hayato Kuroda (Fujitsu) <[email protected]>
2 siblings, 1 reply; 25+ messages in thread
From: Peter Smith @ 2024-05-13 06:34 UTC (permalink / raw)
To: Hayato Kuroda (Fujitsu) <[email protected]>; +Cc: [email protected] <[email protected]>; Amit Kapila <[email protected]>; Ajin Cherian <[email protected]>; Давыдов Виталий <[email protected]>
Hi, Here are some review comments for v8-0002.
======
Commit message
1.
Regarding the off->on case, the logical replication already has a mechanism for
it, so there is no need to do anything special for the on->off case; however,
we must connect to the publisher and expressly change the parameter. The
operation cannot be rolled back, and altering the parameter from "on" to "off"
within a transaction is prohibited.
~
I think the difference between "off"-to"on" and "on"-to"off" needs to
be explained in more detail. Specifically "already has a mechanism for
it" seems very vague.
======
src/backend/commands/subscriptioncmds.c
2.
/*
- * The changed two_phase option of the slot can't be rolled
- * back.
+ * Since the altering two_phase option of subscriptions
+ * also leads to the change of slot option, this command
+ * cannot be rolled back. So prevent we are in the
+ * transaction block.
*/
- PreventInTransactionBlock(isTopLevel, "ALTER SUBSCRIPTION ... SET
(two_phase)");
+ if (!opts.twophase)
+ PreventInTransactionBlock(isTopLevel,
+
2a.
There is a typo: "So prevent we are".
SUGGESTION (minor adjustment and typo fix)
Since altering the two_phase option of subscriptions also leads to
changing the slot option, this command cannot be rolled back. So
prevent this if we are in a transaction block.
~
2b.
But, in my previous review [v7-0002#3] I asked if the comment could
explain why this check is only needed for two_phase "on"-to-"off" but
not for "off"-to-"on". That explanation/reason is still not yet given
in the latest comment.
~~~
3.
/*
- * Try to acquire the connection necessary for altering slot.
+ * Check the need to alter the replication slot. Failover and two_phase
+ * options are controlled by both the publisher (as a slot option) and the
+ * subscriber (as a subscription option).
+ */
+ update_failover = replaces[Anum_pg_subscription_subfailover - 1];
+ update_two_phase = (replaces[Anum_pg_subscription_subtwophasestate - 1] &&
+ !opts.twophase);
(This is similar to the previous comment). In my previous review
[v7-0002#3a] I asked why update_two_phase is TRUE only if 'two-phase'
is being updated "on"-to-"off", but not when it is being updated
"off"-to-"on". That explanation/reason is still not yet given in the
latest comment.
======
src/backend/replication/libpqwalreceiver/libpqwalreceiver.c
4.
- appendStringInfo(&cmd, "ALTER_REPLICATION_SLOT %s ( FAILOVER %s,
TWO_PHASE %s )",
- quote_identifier(slotname),
- failover ? "true" : "false",
- two_phase ? "true" : "false");
+ appendStringInfo(&cmd, "ALTER_REPLICATION_SLOT %s ( ",
+ quote_identifier(slotname));
+
+ if (failover)
+ appendStringInfo(&cmd, "FAILOVER %s",
+ *failover ? "true" : "false");
+
+ if (failover && two_phase)
+ appendStringInfo(&cmd, ", ");
+
+ if (two_phase)
+ appendStringInfo(&cmd, "TWO_PHASE %s",
+ *two_phase ? "true" : "false");
+
+ appendStringInfoString(&cmd, ");");
It will be better if that last line includes the extra space like I
had suggested in [v7-0002#4a] so the result will have the same spacing
as in the original code. e.g.
+ appendStringInfoString(&cmd, " );");
======
src/test/subscription/t/099_twophase_added.pl
5.
+# Check the case that prepared transactions exist on the publisher node.
+#
+# Since the two_phase is "off", then normally, this PREPARE will do nothing
+# until the COMMIT PREPARED, but in this test, we toggle the two_phase to "on"
+# again before the COMMIT PREPARED happens.
This is a major test part so IMO this comment should have
##################### like it had before, to distinguish it from all
the sub-step comments.
======
My v7-0002 review -
https://www.postgresql.org/message-id/CAHut%2BPtu_w_UCGR-5DbenA%2By7wRiA8QPi_ZP%3DCCJ3SGdTn-%3D%3Dg%...
Kind Regards,
Peter Smith.
Fujitsu Australia.
^ permalink raw reply [nested|flat] 25+ messages in thread
* Re: Slow catchup of 2PC (twophase) transactions on replica in LR
@ 2024-05-13 06:37 Peter Smith <[email protected]>
parent: Hayato Kuroda (Fujitsu) <[email protected]>
2 siblings, 1 reply; 25+ messages in thread
From: Peter Smith @ 2024-05-13 06:37 UTC (permalink / raw)
To: Hayato Kuroda (Fujitsu) <[email protected]>; +Cc: [email protected] <[email protected]>; Amit Kapila <[email protected]>; Ajin Cherian <[email protected]>; Давыдов Виталий <[email protected]>
Hi, Here are some review comments for v8-0003.
======
src/sgml/ref/alter_subscription.sgml
1.
+ <para>
+ The <literal>two_phase</literal> parameter can only be altered when the
+ subscription is disabled. When altering the parameter from
<literal>on</literal>
+ to <literal>off</literal>, the backend process checks prepared
+ transactions done by the logical replication worker and aborts them.
+ </para>
The text may be OK as-is, but I was wondering if it might be better to
give a more verbose explanation.
BEFORE
... the backend process checks prepared transactions done by the
logical replication worker and aborts them.
SUGGESTION
... the backend process checks for any incomplete prepared
transactions done by the logical replication worker (from when
two_phase parameter was still "on") and, if any are found, those are
aborted.
======
src/backend/commands/subscriptioncmds.c
2. AlterSubscription
- /*
- * Since the altering two_phase option of subscriptions
- * also leads to the change of slot option, this command
- * cannot be rolled back. So prevent we are in the
- * transaction block.
+ * If two_phase was enabled, there is a possibility the
+ * transactions has already been PREPARE'd. They must be
+ * checked and rolled back.
*/
BEFORE
... there is a possibility the transactions has already been PREPARE'd.
SUGGESTION
... there is a possibility that transactions have already been PREPARE'd.
~~~
3. AlterSubscription
+ /*
+ * Since the altering two_phase option of subscriptions
+ * (especially on->off case) also leads to the
+ * change of slot option, this command cannot be rolled
+ * back. So prevent we are in the transaction block.
+ */
PreventInTransactionBlock(isTopLevel,
"ALTER SUBSCRIPTION ... SET (two_phase = off)");
This comment is a bit vague and includes some typos, but IIUC these
problems will already be addressed by the 0002 patch changes.AFAIK
patch 0003 is only moving the 0002 comment.
======
src/test/subscription/t/099_twophase_added.pl
4.
+# Check the case that prepared transactions exist on the subscriber node
+#
+# If the two_phase is altering from "on" to "off" and there are prepared
+# transactions on the subscriber, they must be aborted. This test checks it.
+
Similar to the comment that I gave for v8-0002. I think there should
be #################### comment for the major test comment to
distinguish it from comments for the sub-steps.
~~~
5.
+# Verify the prepared transaction are aborted because two_phase is changed to
+# "off".
+$result = $node_subscriber->safe_psql('postgres',
+ "SELECT count(*) FROM pg_prepared_xacts;");
+is($result, q(0), "prepared transaction done by worker is aborted");
+
/the prepared transaction are aborted/any prepared transactions are aborted/
======
Kind Regards,
Peter Smith
Fujitsu Australia
^ permalink raw reply [nested|flat] 25+ messages in thread
* Re: Slow catchup of 2PC (twophase) transactions on replica in LR
@ 2024-05-13 06:40 Peter Smith <[email protected]>
parent: Hayato Kuroda (Fujitsu) <[email protected]>
2 siblings, 1 reply; 25+ messages in thread
From: Peter Smith @ 2024-05-13 06:40 UTC (permalink / raw)
To: Hayato Kuroda (Fujitsu) <[email protected]>; +Cc: [email protected] <[email protected]>; Amit Kapila <[email protected]>; Ajin Cherian <[email protected]>; Давыдов Виталий <[email protected]>
Hi, Here are some comments for v8-0004
======
0.1 General - Patch name
/SUBSCIRPTION/SUBSCRIPTION/
======
0.2 General - Apply
FYI, there are whitespace warnings:
git apply ../patches_misc/v8-0004-Add-force_alter-option-for-ALTER-SUBSCIRPTION-.-S.patch
../patches_misc/v8-0004-Add-force_alter-option-for-ALTER-SUBSCIRPTION-.-S.patch:191:
trailing whitespace.
# command will abort the prepared transaction and succeed.
warning: 1 line adds whitespace errors.
======
0.3 General - Regression test fails
The subscription regression tests are not working.
ok 158 + publication 1187 ms
not ok 159 + subscription 123 ms
See review comments #4 and #5 below for the reason why.
======
src/sgml/ref/alter_subscription.sgml
1.
<para>
The <literal>two_phase</literal> parameter can only be altered when the
- subscription is disabled. When altering the parameter from
<literal>on</literal>
- to <literal>off</literal>, the backend process checks prepared
- transactions done by the logical replication worker and aborts them.
+ subscription is disabled. Altering the parameter from
<literal>on</literal>
+ to <literal>off</literal> will be failed when there are prepared
+ transactions done by the logical replication worker. If you want to alter
+ the parameter forcibly in this case, <literal>force_alter</literal>
+ option must be set to <literal>on</literal> at the same time. If
+ specified, the backend process aborts prepared transactions.
</para>
1a.
That "will be failed when..." seems strange. Maybe say "will give an
error when..."
~
1b.
Because "force" is a verb, I think true/false is more natural than
on/off for this new boolean option. e.g. it acts more like a "flag"
than a "mode". See all the other boolean options in CREATE
SUBSCRIPTION -- those are mostly all verbs too and are all true/false
AFAIK.
======
2. CREATE SUBSCRIPTION
For my previous review, two comments [v7-0004#2] and [v7-0004#3] were
not addressed. Kuroda-san wrote:
Hmm, but the parameter cannot be used for CREATE SUBSCRIPTION. Should
we modify to accept and add the description in the doc?
~
Yes, that is what I am suggesting. IMO it is odd for the user to be
able to ALTER a parameter that cannot be included in the CREATE
SUBSCRIPTION in the first place. AFAIK there are no other parameters
that behave that way.
======
src/backend/commands/subscriptioncmds.c
3. AlterSubscription
+ if (!opts.force_alter)
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("cannot alter %s when there are prepared transactions",
+ "two_phase = off"),
+ errhint("Resolve these transactions or set %s at the same time, and
then try again.",
+ "force_alter = true")));
I think saying "at the same time" in the hint is unnecessary. Surely
the user is allowed to set this parameter separately if they want to?
e.g.
ALTER SUBSCRIPTION sub SET (force_alter=true);
ALTER SUBSCRIPTION sub SET (two_phase=off);
======
src/test/regress/expected/subscription.out
4.
+-- fail - force_alter cannot be set alone
+ALTER SUBSCRIPTION regress_testsub SET (force_alter = true);
+ERROR: force_alter must be specified with two_phase
This error cannot happen. You removed that error!
======
src/test/regress/sql/subscription.sql
5.
+-- fail - force_alter cannot be set alone
+ALTER SUBSCRIPTION regress_testsub SET (force_alter = true);
Why is this being tested? You removed that error condition.
======
src/test/subscription/t/099_twophase_added.pl
6.
+# Try altering the two_phase option to "off." The command will fail since there
+# is a prepared transaction and the force option is not specified.
+my $stdout;
+my $stderr;
+
+($result, $stdout, $stderr) = $node_subscriber->psql(
+ 'postgres', "ALTER SUBSCRIPTION regress_sub SET (two_phase = off);");
+ok($stderr =~ /cannot alter two_phase = off when there are prepared
transactions/,
+ 'ALTER SUBSCRIPTION failed');
/force option is not specified./'force_alter' option is not specified as true./
~~~
7.
+# Verify the prepared transaction still exists
+$result = $node_subscriber->safe_psql('postgres',
+ "SELECT count(*) FROM pg_prepared_xacts;");
+is($result, q(1), "prepared transaction still exits");
+
TYPO: /exits/exists/
~~~
8.
+# Alter the two_phase with the force_alter option. Apart from the above, the
+# command will abort the prepared transaction and succeed.
+$node_subscriber->safe_psql('postgres',
+ "ALTER SUBSCRIPTION regress_sub SET (two_phase = off, force_alter
= true);");
+$node_subscriber->safe_psql('postgres', "ALTER SUBSCRIPTION
regress_sub ENABLE;");
+
What does "Apart from the above" mean? Be more explicit.
~~~
9.
+# Verify the prepared transaction are aborted
$result = $node_subscriber->safe_psql('postgres',
"SELECT count(*) FROM pg_prepared_xacts;");
is($result, q(0), "prepared transaction done by worker is aborted");
/transaction are aborted/transaction was aborted/
======
Response to my v7-0004 review --
https://www.postgresql.org/message-id/OSBPR01MB2552F738ACF1DA6838025C4FF5E62%40OSBPR01MB2552.jpnprd0...
Kind Regards,
Peter Smith.
Fujitsu Australia
^ permalink raw reply [nested|flat] 25+ messages in thread
* RE: Slow catchup of 2PC (twophase) transactions on replica in LR
@ 2024-05-13 12:25 Hayato Kuroda (Fujitsu) <[email protected]>
parent: Peter Smith <[email protected]>
0 siblings, 2 replies; 25+ messages in thread
From: Hayato Kuroda (Fujitsu) @ 2024-05-13 12:25 UTC (permalink / raw)
To: 'Peter Smith' <[email protected]>; +Cc: [email protected] <[email protected]>; Amit Kapila <[email protected]>; Ajin Cherian <[email protected]>; Давыдов Виталий <[email protected]>
Dear Peter,
Thanks for giving comments! I attached updated version.
> 1.
> Regarding the off->on case, the logical replication already has a mechanism for
> it, so there is no need to do anything special for the on->off case; however,
> we must connect to the publisher and expressly change the parameter. The
> operation cannot be rolled back, and altering the parameter from "on" to "off"
> within a transaction is prohibited.
>
> ~
>
> I think the difference between "off"-to"on" and "on"-to"off" needs to
> be explained in more detail. Specifically "already has a mechanism for
> it" seems very vague.
New paragraph was added.
>
> ======
> src/backend/commands/subscriptioncmds.c
>
> 2.
> /*
> - * The changed two_phase option of the slot can't be rolled
> - * back.
> + * Since the altering two_phase option of subscriptions
> + * also leads to the change of slot option, this command
> + * cannot be rolled back. So prevent we are in the
> + * transaction block.
> */
> - PreventInTransactionBlock(isTopLevel, "ALTER SUBSCRIPTION ... SET
> (two_phase)");
> + if (!opts.twophase)
> + PreventInTransactionBlock(isTopLevel,
> +
>
> 2a.
> There is a typo: "So prevent we are".
>
> SUGGESTION (minor adjustment and typo fix)
> Since altering the two_phase option of subscriptions also leads to
> changing the slot option, this command cannot be rolled back. So
> prevent this if we are in a transaction block.
Fixed.
> 2b.
> But, in my previous review [v7-0002#3] I asked if the comment could
> explain why this check is only needed for two_phase "on"-to-"off" but
> not for "off"-to-"on". That explanation/reason is still not yet given
> in the latest comment.
Added.
> 3.
> /*
> - * Try to acquire the connection necessary for altering slot.
> + * Check the need to alter the replication slot. Failover and two_phase
> + * options are controlled by both the publisher (as a slot option) and the
> + * subscriber (as a subscription option).
> + */
> + update_failover = replaces[Anum_pg_subscription_subfailover - 1];
> + update_two_phase = (replaces[Anum_pg_subscription_subtwophasestate - 1]
> &&
> + !opts.twophase);
>
>
> (This is similar to the previous comment). In my previous review
> [v7-0002#3a] I asked why update_two_phase is TRUE only if 'two-phase'
> is being updated "on"-to-"off", but not when it is being updated
> "off"-to-"on". That explanation/reason is still not yet given in the
> latest comment.
Added.
>
> ======
> src/backend/replication/libpqwalreceiver/libpqwalreceiver.c
>
> 4.
> - appendStringInfo(&cmd, "ALTER_REPLICATION_SLOT %s ( FAILOVER %s,
> TWO_PHASE %s )",
> - quote_identifier(slotname),
> - failover ? "true" : "false",
> - two_phase ? "true" : "false");
> + appendStringInfo(&cmd, "ALTER_REPLICATION_SLOT %s ( ",
> + quote_identifier(slotname));
> +
> + if (failover)
> + appendStringInfo(&cmd, "FAILOVER %s",
> + *failover ? "true" : "false");
> +
> + if (failover && two_phase)
> + appendStringInfo(&cmd, ", ");
> +
> + if (two_phase)
> + appendStringInfo(&cmd, "TWO_PHASE %s",
> + *two_phase ? "true" : "false");
> +
> + appendStringInfoString(&cmd, ");");
>
> It will be better if that last line includes the extra space like I
> had suggested in [v7-0002#4a] so the result will have the same spacing
> as in the original code. e.g.
>
> + appendStringInfoString(&cmd, " );");
I missed the blank, added.
>
> ======
> src/test/subscription/t/099_twophase_added.pl
>
> 5.
> +# Check the case that prepared transactions exist on the publisher node.
> +#
> +# Since the two_phase is "off", then normally, this PREPARE will do nothing
> +# until the COMMIT PREPARED, but in this test, we toggle the two_phase to "on"
> +# again before the COMMIT PREPARED happens.
>
> This is a major test part so IMO this comment should have
> ##################### like it had before, to distinguish it from all
> the sub-step comments.
Added.
Best Regards,
Hayato Kuroda
FUJITSU LIMITED
https://www.fujitsu.com/
Attachments:
[application/octet-stream] v9-0001-Allow-altering-of-two_phase-option-of-a-SUBSCRIPT.patch (25.5K, ../../OSBPR01MB2552FEA48D265EA278AA9F7AF5E22@OSBPR01MB2552.jpnprd01.prod.outlook.com/2-v9-0001-Allow-altering-of-two_phase-option-of-a-SUBSCRIPT.patch)
download | inline diff:
From 64bcb161e2386010dd7d3cd50fd7ab51e6bddb1f Mon Sep 17 00:00:00 2001
From: Ajin Cherian <[email protected]>
Date: Fri, 5 Apr 2024 06:47:18 -0400
Subject: [PATCH v9 1/4] Allow altering of two_phase option of a SUBSCRIPTION
This patch allows the user to alter the 'two_phase' option of a subscriber provided no
uncommitted prepared transactions are pending on that subscription.
Author: Cherian Ajin, Hayato Kuroda
---
doc/src/sgml/ref/alter_subscription.sgml | 12 ++--
src/backend/access/transam/twophase.c | 62 ++++++++++++++++
src/backend/commands/subscriptioncmds.c | 67 +++++++++++++----
.../libpqwalreceiver/libpqwalreceiver.c | 9 +--
src/backend/replication/logical/launcher.c | 22 ++++++
src/backend/replication/logical/worker.c | 21 +-----
src/backend/replication/slot.c | 18 ++++-
src/backend/replication/walsender.c | 18 ++++-
src/bin/psql/tab-complete.c | 2 +-
src/include/access/twophase.h | 5 ++
src/include/replication/slot.h | 3 +-
src/include/replication/walreceiver.h | 11 +--
src/include/replication/worker_internal.h | 1 +
src/test/regress/expected/subscription.out | 5 +-
src/test/regress/sql/subscription.sql | 5 +-
src/test/subscription/t/021_twophase.pl | 71 ++++++++++++++++++-
16 files changed, 269 insertions(+), 63 deletions(-)
diff --git a/doc/src/sgml/ref/alter_subscription.sgml b/doc/src/sgml/ref/alter_subscription.sgml
index a78c1c3a47..88e9a72147 100644
--- a/doc/src/sgml/ref/alter_subscription.sgml
+++ b/doc/src/sgml/ref/alter_subscription.sgml
@@ -68,8 +68,9 @@ ALTER SUBSCRIPTION <replaceable class="parameter">name</replaceable> RENAME TO <
<para>
Commands <command>ALTER SUBSCRIPTION ... REFRESH PUBLICATION</command>,
<command>ALTER SUBSCRIPTION ... {SET|ADD|DROP} PUBLICATION ...</command>
- with <literal>refresh</literal> option as <literal>true</literal> and
- <command>ALTER SUBSCRIPTION ... SET (failover = on|off)</command>
+ with <literal>refresh</literal> option as <literal>true</literal>,
+ <command>ALTER SUBSCRIPTION ... SET (failover = on|off)</command> and
+ <command>ALTER SUBSCRIPTION ... SET (two_phase = on|off)</command>
cannot be executed inside a transaction block.
These commands also cannot be executed when the subscription has
@@ -228,9 +229,12 @@ ALTER SUBSCRIPTION <replaceable class="parameter">name</replaceable> RENAME TO <
<link linkend="sql-createsubscription-params-with-disable-on-error"><literal>disable_on_error</literal></link>,
<link linkend="sql-createsubscription-params-with-password-required"><literal>password_required</literal></link>,
<link linkend="sql-createsubscription-params-with-run-as-owner"><literal>run_as_owner</literal></link>,
- <link linkend="sql-createsubscription-params-with-origin"><literal>origin</literal></link>, and
- <link linkend="sql-createsubscription-params-with-failover"><literal>failover</literal></link>.
+ <link linkend="sql-createsubscription-params-with-origin"><literal>origin</literal></link>,
+ <link linkend="sql-createsubscription-params-with-failover"><literal>failover</literal></link>, and
+ <link linkend="sql-createsubscription-params-with-two-phase"><literal>two_phase</literal></link>.
Only a superuser can set <literal>password_required = false</literal>.
+ The <literal>two_phase</literal> parameter can only be altered when the
+ subscription is disabled.
</para>
<para>
diff --git a/src/backend/access/transam/twophase.c b/src/backend/access/transam/twophase.c
index 8090ac9fc1..66fa591eb5 100644
--- a/src/backend/access/transam/twophase.c
+++ b/src/backend/access/transam/twophase.c
@@ -2682,3 +2682,65 @@ LookupGXact(const char *gid, XLogRecPtr prepare_end_lsn,
LWLockRelease(TwoPhaseStateLock);
return found;
}
+
+/*
+ * TwoPhaseTransactionGid
+ * Form the prepared transaction GID for two_phase transactions.
+ *
+ * Return the GID in the supplied buffer.
+ */
+void
+TwoPhaseTransactionGid(Oid subid, TransactionId xid, char *gid, int szgid)
+{
+ Assert(subid != InvalidRepOriginId);
+
+ if (!TransactionIdIsValid(xid))
+ ereport(ERROR,
+ (errcode(ERRCODE_PROTOCOL_VIOLATION),
+ errmsg_internal("invalid two-phase transaction ID")));
+
+ snprintf(gid, szgid, "pg_gid_%u_%u", subid, xid);
+}
+
+/*
+ * IsTwoPhaseTransactionGidForSubid
+ * Check whether the given GID (as formed by TwoPhaseTransactionGid) is
+ * for the specified 'subid'.
+ */
+static bool
+IsTwoPhaseTransactionGidForSubid(Oid subid, char *gid)
+{
+ int ret;
+ Oid subid_written;
+ TransactionId xid;
+
+ ret = sscanf(gid, "pg_gid_%u_%u", &subid_written, &xid);
+
+ return (ret == 2 && subid == subid_written);
+}
+
+/*
+ * LookupGXactBySubid
+ * Check if the prepared transaction done by apply worker exists.
+ */
+bool
+LookupGXactBySubid(Oid subid)
+{
+ bool found = false;
+
+ LWLockAcquire(TwoPhaseStateLock, LW_SHARED);
+ for (int i = 0; i < TwoPhaseState->numPrepXacts; i++)
+ {
+ GlobalTransaction gxact = TwoPhaseState->prepXacts[i];
+
+ /* Ignore not-yet-valid GIDs. */
+ if (gxact->valid &&
+ IsTwoPhaseTransactionGidForSubid(subid, gxact->gid))
+ {
+ found = true;
+ break;
+ }
+ }
+ LWLockRelease(TwoPhaseStateLock);
+ return found;
+}
diff --git a/src/backend/commands/subscriptioncmds.c b/src/backend/commands/subscriptioncmds.c
index e407428dbc..90d967eb7c 100644
--- a/src/backend/commands/subscriptioncmds.c
+++ b/src/backend/commands/subscriptioncmds.c
@@ -16,6 +16,7 @@
#include "access/htup_details.h"
#include "access/table.h"
+#include "access/twophase.h"
#include "access/xact.h"
#include "catalog/catalog.h"
#include "catalog/dependency.h"
@@ -1143,7 +1144,8 @@ AlterSubscription(ParseState *pstate, AlterSubscriptionStmt *stmt,
{
supported_opts = (SUBOPT_SLOT_NAME |
SUBOPT_SYNCHRONOUS_COMMIT | SUBOPT_BINARY |
- SUBOPT_STREAMING | SUBOPT_DISABLE_ON_ERR |
+ SUBOPT_STREAMING | SUBOPT_TWOPHASE_COMMIT |
+ SUBOPT_DISABLE_ON_ERR |
SUBOPT_PASSWORD_REQUIRED |
SUBOPT_RUN_AS_OWNER | SUBOPT_FAILOVER |
SUBOPT_ORIGIN);
@@ -1151,6 +1153,52 @@ AlterSubscription(ParseState *pstate, AlterSubscriptionStmt *stmt,
parse_subscription_options(pstate, stmt->options,
supported_opts, &opts);
+ if (IsSet(opts.specified_opts, SUBOPT_TWOPHASE_COMMIT))
+ {
+ /*
+ * Do not allow changing the two_phase option if the
+ * subscription is enabled. This is because the two_phase
+ * option of the slot on the publisher cannot be modified
+ * if the slot is currently acquired by the apply worker.
+ */
+ if (form->subenabled)
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("cannot set %s for enabled subscription",
+ "two_phase")));
+
+ /*
+ * Stop all the subscription workers, just in case. Workers
+ * may still survive even if the subscription is disabled.
+ */
+ logicalrep_workers_stop(subid);
+
+ /*
+ * two_phase cannot be disabled if there are any
+ * uncommitted prepared transactions present.
+ */
+ if (!opts.twophase &&
+ form->subtwophasestate == LOGICALREP_TWOPHASE_STATE_ENABLED &&
+ LookupGXactBySubid(subid))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("cannot disable two_phase when uncommitted prepared transactions present"),
+ errhint("Resolve these transactions and try again")));
+
+ /*
+ * The changed two_phase option of the slot can't be rolled
+ * back.
+ */
+ PreventInTransactionBlock(isTopLevel, "ALTER SUBSCRIPTION ... SET (two_phase)");
+
+ /* Change system catalog acoordingly */
+ values[Anum_pg_subscription_subtwophasestate - 1] =
+ CharGetDatum(opts.twophase ?
+ LOGICALREP_TWOPHASE_STATE_PENDING :
+ LOGICALREP_TWOPHASE_STATE_DISABLED);
+ replaces[Anum_pg_subscription_subtwophasestate - 1] = true;
+ }
+
if (IsSet(opts.specified_opts, SUBOPT_SLOT_NAME))
{
/*
@@ -1505,7 +1553,8 @@ AlterSubscription(ParseState *pstate, AlterSubscriptionStmt *stmt,
* doing the database operations we won't be able to rollback altered
* slot.
*/
- if (replaces[Anum_pg_subscription_subfailover - 1])
+ if (replaces[Anum_pg_subscription_subfailover - 1] ||
+ replaces[Anum_pg_subscription_subtwophasestate - 1])
{
bool must_use_password;
char *err;
@@ -1525,7 +1574,7 @@ AlterSubscription(ParseState *pstate, AlterSubscriptionStmt *stmt,
PG_TRY();
{
- walrcv_alter_slot(wrconn, sub->slotname, opts.failover);
+ walrcv_alter_slot(wrconn, sub->slotname, opts.failover, opts.twophase);
}
PG_FINALLY();
{
@@ -1562,7 +1611,6 @@ DropSubscription(DropSubscriptionStmt *stmt, bool isTopLevel)
char *subname;
char *conninfo;
char *slotname;
- List *subworkers;
ListCell *lc;
char originname[NAMEDATALEN];
char *err = NULL;
@@ -1672,16 +1720,7 @@ DropSubscription(DropSubscriptionStmt *stmt, bool isTopLevel)
* New workers won't be started because we hold an exclusive lock on the
* subscription till the end of the transaction.
*/
- LWLockAcquire(LogicalRepWorkerLock, LW_SHARED);
- subworkers = logicalrep_workers_find(subid, false);
- LWLockRelease(LogicalRepWorkerLock);
- foreach(lc, subworkers)
- {
- LogicalRepWorker *w = (LogicalRepWorker *) lfirst(lc);
-
- logicalrep_worker_stop(w->subid, w->relid);
- }
- list_free(subworkers);
+ logicalrep_workers_stop(subid);
/*
* Remove the no-longer-useful entry in the launcher's table of apply
diff --git a/src/backend/replication/libpqwalreceiver/libpqwalreceiver.c b/src/backend/replication/libpqwalreceiver/libpqwalreceiver.c
index 3c2b1bb496..998bbd517a 100644
--- a/src/backend/replication/libpqwalreceiver/libpqwalreceiver.c
+++ b/src/backend/replication/libpqwalreceiver/libpqwalreceiver.c
@@ -80,7 +80,7 @@ static char *libpqrcv_create_slot(WalReceiverConn *conn,
CRSSnapshotAction snapshot_action,
XLogRecPtr *lsn);
static void libpqrcv_alter_slot(WalReceiverConn *conn, const char *slotname,
- bool failover);
+ bool failover, bool two_phase);
static pid_t libpqrcv_get_backend_pid(WalReceiverConn *conn);
static WalRcvExecResult *libpqrcv_exec(WalReceiverConn *conn,
const char *query,
@@ -1121,15 +1121,16 @@ libpqrcv_create_slot(WalReceiverConn *conn, const char *slotname,
*/
static void
libpqrcv_alter_slot(WalReceiverConn *conn, const char *slotname,
- bool failover)
+ bool failover, bool two_phase)
{
StringInfoData cmd;
PGresult *res;
initStringInfo(&cmd);
- appendStringInfo(&cmd, "ALTER_REPLICATION_SLOT %s ( FAILOVER %s )",
+ appendStringInfo(&cmd, "ALTER_REPLICATION_SLOT %s ( FAILOVER %s, TWO_PHASE %s )",
quote_identifier(slotname),
- failover ? "true" : "false");
+ failover ? "true" : "false",
+ two_phase ? "true" : "false");
res = libpqrcv_PQexec(conn->streamConn, cmd.data);
pfree(cmd.data);
diff --git a/src/backend/replication/logical/launcher.c b/src/backend/replication/logical/launcher.c
index 66070e9131..548f6e0edb 100644
--- a/src/backend/replication/logical/launcher.c
+++ b/src/backend/replication/logical/launcher.c
@@ -623,6 +623,28 @@ logicalrep_worker_stop(Oid subid, Oid relid)
LWLockRelease(LogicalRepWorkerLock);
}
+/*
+ * Stop all the subscription workers.
+ */
+void
+logicalrep_workers_stop(Oid subid)
+{
+ List *subworkers;
+ ListCell *lc;
+
+ LWLockAcquire(LogicalRepWorkerLock, LW_SHARED);
+ /* XXX clarify the reason why not only running workers are listed. */
+ subworkers = logicalrep_workers_find(subid, false);
+ LWLockRelease(LogicalRepWorkerLock);
+ foreach(lc, subworkers)
+ {
+ LogicalRepWorker *w = (LogicalRepWorker *) lfirst(lc);
+
+ logicalrep_worker_stop(w->subid, w->relid);
+ }
+ list_free(subworkers);
+}
+
/*
* Stop the given logical replication parallel apply worker.
*
diff --git a/src/backend/replication/logical/worker.c b/src/backend/replication/logical/worker.c
index b5a80fe3e8..dcf656fd45 100644
--- a/src/backend/replication/logical/worker.c
+++ b/src/backend/replication/logical/worker.c
@@ -402,7 +402,6 @@ static void apply_handle_tuple_routing(ApplyExecutionData *edata,
CmdType operation);
/* Compute GID for two_phase transactions */
-static void TwoPhaseTransactionGid(Oid subid, TransactionId xid, char *gid, int szgid);
/* Functions for skipping changes */
static void maybe_start_skipping_changes(XLogRecPtr finish_lsn);
@@ -3911,7 +3910,7 @@ maybe_reread_subscription(void)
/* !slotname should never happen when enabled is true. */
Assert(newsub->slotname);
- /* two-phase should not be altered */
+ /* two-phase cannot be altered while the worker exists */
Assert(newsub->twophasestate == MySubscription->twophasestate);
/*
@@ -4396,24 +4395,6 @@ cleanup_subxact_info()
subxact_data.nsubxacts_max = 0;
}
-/*
- * Form the prepared transaction GID for two_phase transactions.
- *
- * Return the GID in the supplied buffer.
- */
-static void
-TwoPhaseTransactionGid(Oid subid, TransactionId xid, char *gid, int szgid)
-{
- Assert(subid != InvalidRepOriginId);
-
- if (!TransactionIdIsValid(xid))
- ereport(ERROR,
- (errcode(ERRCODE_PROTOCOL_VIOLATION),
- errmsg_internal("invalid two-phase transaction ID")));
-
- snprintf(gid, szgid, "pg_gid_%u_%u", subid, xid);
-}
-
/*
* Common function to run the apply loop with error handling. Disable the
* subscription, if necessary.
diff --git a/src/backend/replication/slot.c b/src/backend/replication/slot.c
index aa4ea387da..d0c8d5a4df 100644
--- a/src/backend/replication/slot.c
+++ b/src/backend/replication/slot.c
@@ -804,8 +804,10 @@ ReplicationSlotDrop(const char *name, bool nowait)
* Change the definition of the slot identified by the specified name.
*/
void
-ReplicationSlotAlter(const char *name, bool failover)
+ReplicationSlotAlter(const char *name, bool failover, bool two_phase)
{
+ bool update_slot = false;
+
Assert(MyReplicationSlot == NULL);
ReplicationSlotAcquire(name, false);
@@ -854,6 +856,20 @@ ReplicationSlotAlter(const char *name, bool failover)
MyReplicationSlot->data.failover = failover;
SpinLockRelease(&MyReplicationSlot->mutex);
+ update_slot = true;
+ }
+
+ if (MyReplicationSlot->data.two_phase != two_phase)
+ {
+ SpinLockAcquire(&MyReplicationSlot->mutex);
+ MyReplicationSlot->data.two_phase = two_phase;
+ SpinLockRelease(&MyReplicationSlot->mutex);
+
+ update_slot = true;
+ }
+
+ if (update_slot)
+ {
ReplicationSlotMarkDirty();
ReplicationSlotSave();
}
diff --git a/src/backend/replication/walsender.c b/src/backend/replication/walsender.c
index c623b07cf0..2e6ca35049 100644
--- a/src/backend/replication/walsender.c
+++ b/src/backend/replication/walsender.c
@@ -1411,9 +1411,11 @@ DropReplicationSlot(DropReplicationSlotCmd *cmd)
* Process extra options given to ALTER_REPLICATION_SLOT.
*/
static void
-ParseAlterReplSlotOptions(AlterReplicationSlotCmd *cmd, bool *failover)
+ParseAlterReplSlotOptions(AlterReplicationSlotCmd *cmd,
+ bool *failover, bool *two_phase)
{
bool failover_given = false;
+ bool two_phase_given = false;
/* Parse options */
foreach_ptr(DefElem, defel, cmd->options)
@@ -1427,6 +1429,15 @@ ParseAlterReplSlotOptions(AlterReplicationSlotCmd *cmd, bool *failover)
failover_given = true;
*failover = defGetBoolean(defel);
}
+ else if (strcmp(defel->defname, "two_phase") == 0)
+ {
+ if (two_phase_given)
+ ereport(ERROR,
+ (errcode(ERRCODE_SYNTAX_ERROR),
+ errmsg("conflicting or redundant options")));
+ two_phase_given = true;
+ *two_phase = defGetBoolean(defel);
+ }
else
elog(ERROR, "unrecognized option: %s", defel->defname);
}
@@ -1439,9 +1450,10 @@ static void
AlterReplicationSlot(AlterReplicationSlotCmd *cmd)
{
bool failover = false;
+ bool two_phase = false;
- ParseAlterReplSlotOptions(cmd, &failover);
- ReplicationSlotAlter(cmd->slotname, failover);
+ ParseAlterReplSlotOptions(cmd, &failover, &two_phase);
+ ReplicationSlotAlter(cmd->slotname, failover, two_phase);
}
/*
diff --git a/src/bin/psql/tab-complete.c b/src/bin/psql/tab-complete.c
index d453e224d9..891face1b6 100644
--- a/src/bin/psql/tab-complete.c
+++ b/src/bin/psql/tab-complete.c
@@ -1948,7 +1948,7 @@ psql_completion(const char *text, int start, int end)
else if (HeadMatches("ALTER", "SUBSCRIPTION", MatchAny) && TailMatches("SET", "("))
COMPLETE_WITH("binary", "disable_on_error", "failover", "origin",
"password_required", "run_as_owner", "slot_name",
- "streaming", "synchronous_commit");
+ "streaming", "synchronous_commit", "two_phase");
/* ALTER SUBSCRIPTION <name> SKIP ( */
else if (HeadMatches("ALTER", "SUBSCRIPTION", MatchAny) && TailMatches("SKIP", "("))
COMPLETE_WITH("lsn");
diff --git a/src/include/access/twophase.h b/src/include/access/twophase.h
index 56248c0006..d37e06fdee 100644
--- a/src/include/access/twophase.h
+++ b/src/include/access/twophase.h
@@ -62,4 +62,9 @@ extern void PrepareRedoRemove(TransactionId xid, bool giveWarning);
extern void restoreTwoPhaseData(void);
extern bool LookupGXact(const char *gid, XLogRecPtr prepare_end_lsn,
TimestampTz origin_prepare_timestamp);
+
+extern void TwoPhaseTransactionGid(Oid subid, TransactionId xid, char *gid,
+ int szgid);
+extern bool LookupGXactBySubid(Oid subid);
+
#endif /* TWOPHASE_H */
diff --git a/src/include/replication/slot.h b/src/include/replication/slot.h
index 1bc80960ef..014e216cf5 100644
--- a/src/include/replication/slot.h
+++ b/src/include/replication/slot.h
@@ -243,7 +243,8 @@ extern void ReplicationSlotCreate(const char *name, bool db_specific,
extern void ReplicationSlotPersist(void);
extern void ReplicationSlotDrop(const char *name, bool nowait);
extern void ReplicationSlotDropAcquired(void);
-extern void ReplicationSlotAlter(const char *name, bool failover);
+extern void ReplicationSlotAlter(const char *name, bool failover,
+ bool two_phase);
extern void ReplicationSlotAcquire(const char *name, bool nowait);
extern void ReplicationSlotRelease(void);
diff --git a/src/include/replication/walreceiver.h b/src/include/replication/walreceiver.h
index 12f71fa99b..31fa1257ec 100644
--- a/src/include/replication/walreceiver.h
+++ b/src/include/replication/walreceiver.h
@@ -372,12 +372,13 @@ typedef char *(*walrcv_create_slot_fn) (WalReceiverConn *conn,
/*
* walrcv_alter_slot_fn
*
- * Change the definition of a replication slot. Currently, it only supports
- * changing the failover property of the slot.
+ * Change the definition of a replication slot. Currently, it supports
+ * changing the failover and the two_phase property of the slot.
*/
typedef void (*walrcv_alter_slot_fn) (WalReceiverConn *conn,
const char *slotname,
- bool failover);
+ bool failover,
+ bool two_phase);
/*
* walrcv_get_backend_pid_fn
@@ -455,8 +456,8 @@ extern PGDLLIMPORT WalReceiverFunctionsType *WalReceiverFunctions;
WalReceiverFunctions->walrcv_send(conn, buffer, nbytes)
#define walrcv_create_slot(conn, slotname, temporary, two_phase, failover, snapshot_action, lsn) \
WalReceiverFunctions->walrcv_create_slot(conn, slotname, temporary, two_phase, failover, snapshot_action, lsn)
-#define walrcv_alter_slot(conn, slotname, failover) \
- WalReceiverFunctions->walrcv_alter_slot(conn, slotname, failover)
+#define walrcv_alter_slot(conn, slotname, failover, two_phase) \
+ WalReceiverFunctions->walrcv_alter_slot(conn, slotname, failover, two_phase)
#define walrcv_get_backend_pid(conn) \
WalReceiverFunctions->walrcv_get_backend_pid(conn)
#define walrcv_exec(conn, exec, nRetTypes, retTypes) \
diff --git a/src/include/replication/worker_internal.h b/src/include/replication/worker_internal.h
index 515aefd519..d5428263c1 100644
--- a/src/include/replication/worker_internal.h
+++ b/src/include/replication/worker_internal.h
@@ -246,6 +246,7 @@ extern bool logicalrep_worker_launch(LogicalRepWorkerType wtype,
Oid userid, Oid relid,
dsm_handle subworker_dsm);
extern void logicalrep_worker_stop(Oid subid, Oid relid);
+extern void logicalrep_workers_stop(Oid subid);
extern void logicalrep_pa_worker_stop(ParallelApplyWorkerInfo *winfo);
extern void logicalrep_worker_wakeup(Oid subid, Oid relid);
extern void logicalrep_worker_wakeup_ptr(LogicalRepWorker *worker);
diff --git a/src/test/regress/expected/subscription.out b/src/test/regress/expected/subscription.out
index 0f2a25cdc1..51fa4b9690 100644
--- a/src/test/regress/expected/subscription.out
+++ b/src/test/regress/expected/subscription.out
@@ -377,10 +377,7 @@ HINT: To initiate replication, you must manually create the replication slot, e
regress_testsub | regress_subscription_user | f | {testpub} | f | off | p | f | any | t | f | f | off | dbname=regress_doesnotexist | 0/0
(1 row)
---fail - alter of two_phase option not supported.
-ALTER SUBSCRIPTION regress_testsub SET (two_phase = false);
-ERROR: unrecognized subscription parameter: "two_phase"
--- but can alter streaming when two_phase enabled
+-- We can alter streaming when two_phase enabled
ALTER SUBSCRIPTION regress_testsub SET (streaming = true);
\dRs+
List of subscriptions
diff --git a/src/test/regress/sql/subscription.sql b/src/test/regress/sql/subscription.sql
index 3e5ba4cb8c..a3886d79ca 100644
--- a/src/test/regress/sql/subscription.sql
+++ b/src/test/regress/sql/subscription.sql
@@ -256,10 +256,7 @@ CREATE SUBSCRIPTION regress_testsub CONNECTION 'dbname=regress_doesnotexist' PUB
CREATE SUBSCRIPTION regress_testsub CONNECTION 'dbname=regress_doesnotexist' PUBLICATION testpub WITH (connect = false, two_phase = true);
\dRs+
---fail - alter of two_phase option not supported.
-ALTER SUBSCRIPTION regress_testsub SET (two_phase = false);
-
--- but can alter streaming when two_phase enabled
+-- We can alter streaming when two_phase enabled
ALTER SUBSCRIPTION regress_testsub SET (streaming = true);
\dRs+
diff --git a/src/test/subscription/t/021_twophase.pl b/src/test/subscription/t/021_twophase.pl
index 9437cd4c3b..72df258000 100644
--- a/src/test/subscription/t/021_twophase.pl
+++ b/src/test/subscription/t/021_twophase.pl
@@ -367,6 +367,75 @@ $result =
$node_subscriber->safe_psql('postgres', "SELECT count(*) FROM tab_copy;");
is($result, qq(2), 'replicated data in subscriber table');
+# Clean up
+$node_subscriber->safe_psql('postgres', "DROP SUBSCRIPTION tap_sub");
+
+###############################
+# Disable the subscription and alter it to two_phase = false,
+# then verify that the altered subscription reflects the two_phase option.
+###############################
+
+# Alter subscription two_phase to false
+$node_subscriber->safe_psql('postgres',
+ "ALTER SUBSCRIPTION tap_sub_copy DISABLE");
+$node_subscriber->safe_psql('postgres',
+ "ALTER SUBSCRIPTION tap_sub_copy SET (two_phase = false)");
+$node_subscriber->safe_psql('postgres',
+ "ALTER SUBSCRIPTION tap_sub_copy ENABLE");
+
+# Wait for subscription startup
+$node_subscriber->wait_for_subscription_sync($node_publisher, $appname_copy);
+
+# Make sure that the two-phase is disabled on the subscriber
+$result = $node_subscriber->safe_psql('postgres',
+ "SELECT subtwophasestate FROM pg_subscription WHERE subname = 'tap_sub_copy';"
+);
+is($result, qq(d), 'two-phase should be disabled');
+
+# Now do a prepare on the publisher and make sure that it is not replicated.
+$node_publisher->safe_psql(
+ 'postgres', qq{
+ BEGIN;
+ INSERT INTO tab_copy VALUES (100);
+ PREPARE TRANSACTION 'newgid';
+ });
+
+# Wait for the subscriber to catchup
+$node_publisher->wait_for_catchup($appname_copy);
+
+# Make sure there are no prepared transactions on the subscriber
+$result = $node_subscriber->safe_psql('postgres',
+ "SELECT count(*) FROM pg_prepared_xacts;");
+is($result, qq(0), 'should be no prepared transactions on subscriber');
+
+# Now commit the insert and verify that it IS replicated
+$node_publisher->safe_psql('postgres', "COMMIT PREPARED 'newgid';");
+
+# Wait for the subscriber to catchup
+$node_publisher->wait_for_catchup($appname_copy);
+
+# Make sure that the committed transaction is replicated.
+$result =
+ $node_subscriber->safe_psql('postgres', "SELECT count(*) FROM tab_copy;");
+is($result, qq(3), 'replicated data in subscriber table');
+
+# Alter subscription two_phase to true
+$node_subscriber->safe_psql('postgres',
+ "ALTER SUBSCRIPTION tap_sub_copy DISABLE");
+$node_subscriber->safe_psql('postgres',
+ "ALTER SUBSCRIPTION tap_sub_copy SET (two_phase = true)");
+$node_subscriber->safe_psql('postgres',
+ "ALTER SUBSCRIPTION tap_sub_copy ENABLE");
+
+# Wait for subscription startup
+$node_subscriber->wait_for_subscription_sync($node_publisher, $appname_copy);
+
+# Make sure that the two-phase is enabled on the subscriber
+$result = $node_subscriber->safe_psql('postgres',
+ "SELECT subtwophasestate FROM pg_subscription WHERE subname = 'tap_sub_copy';"
+);
+is($result, qq(e), 'two-phase should be enabled');
+
$node_subscriber->safe_psql('postgres', "DROP SUBSCRIPTION tap_sub_copy;");
$node_publisher->safe_psql('postgres', "DROP PUBLICATION tap_pub_copy;");
@@ -374,8 +443,6 @@ $node_publisher->safe_psql('postgres', "DROP PUBLICATION tap_pub_copy;");
# check all the cleanup
###############################
-$node_subscriber->safe_psql('postgres', "DROP SUBSCRIPTION tap_sub");
-
$result = $node_subscriber->safe_psql('postgres',
"SELECT count(*) FROM pg_subscription");
is($result, qq(0), 'check subscription was dropped on subscriber');
--
2.43.0
[application/octet-stream] v9-0002-Alter-slot-option-two_phase-only-when-altering-on.patch (11.6K, ../../OSBPR01MB2552FEA48D265EA278AA9F7AF5E22@OSBPR01MB2552.jpnprd01.prod.outlook.com/3-v9-0002-Alter-slot-option-two_phase-only-when-altering-on.patch)
download | inline diff:
From 73d327729fcece36100bdc9e9b91d2b933c90c39 Mon Sep 17 00:00:00 2001
From: Hayato Kuroda <[email protected]>
Date: Wed, 17 Apr 2024 06:18:23 +0000
Subject: [PATCH v9 2/4] Alter slot option two_phase only when altering "on" to
"off"
Since the two_phase option is controlled by both the publisher (as a slot option)
and the subscriber (as a subscription option), the slot option must also be
modified.
Regarding the off->on case, the logical replication already has a mechanism for
it, so there is no need to do anything special for the on->off case; however,
we must connect to the publisher and expressly change the parameter. The
operation cannot be rolled back, and altering the parameter from "on" to "off"
within a transaction is prohibited.
In the opposite case, there is no need to prevent this because the logical
replication worker already had the mechanism to alter the slot option at a
convenient time.
---
doc/src/sgml/ref/alter_subscription.sgml | 2 +-
src/backend/commands/subscriptioncmds.c | 36 +++++--
.../libpqwalreceiver/libpqwalreceiver.c | 23 +++--
src/include/replication/walreceiver.h | 5 +-
src/test/subscription/meson.build | 1 +
src/test/subscription/t/099_twophase_added.pl | 96 +++++++++++++++++++
6 files changed, 147 insertions(+), 16 deletions(-)
create mode 100644 src/test/subscription/t/099_twophase_added.pl
diff --git a/doc/src/sgml/ref/alter_subscription.sgml b/doc/src/sgml/ref/alter_subscription.sgml
index 88e9a72147..0c2894a94e 100644
--- a/doc/src/sgml/ref/alter_subscription.sgml
+++ b/doc/src/sgml/ref/alter_subscription.sgml
@@ -70,7 +70,7 @@ ALTER SUBSCRIPTION <replaceable class="parameter">name</replaceable> RENAME TO <
<command>ALTER SUBSCRIPTION ... {SET|ADD|DROP} PUBLICATION ...</command>
with <literal>refresh</literal> option as <literal>true</literal>,
<command>ALTER SUBSCRIPTION ... SET (failover = on|off)</command> and
- <command>ALTER SUBSCRIPTION ... SET (two_phase = on|off)</command>
+ <command>ALTER SUBSCRIPTION ... SET (two_phase = off)</command>
cannot be executed inside a transaction block.
These commands also cannot be executed when the subscription has
diff --git a/src/backend/commands/subscriptioncmds.c b/src/backend/commands/subscriptioncmds.c
index 90d967eb7c..4021defcea 100644
--- a/src/backend/commands/subscriptioncmds.c
+++ b/src/backend/commands/subscriptioncmds.c
@@ -1097,6 +1097,8 @@ AlterSubscription(ParseState *pstate, AlterSubscriptionStmt *stmt,
Form_pg_subscription form;
bits32 supported_opts;
SubOpts opts = {0};
+ bool update_failover;
+ bool update_two_phase;
rel = table_open(SubscriptionRelationId, RowExclusiveLock);
@@ -1186,10 +1188,17 @@ AlterSubscription(ParseState *pstate, AlterSubscriptionStmt *stmt,
errhint("Resolve these transactions and try again")));
/*
- * The changed two_phase option of the slot can't be rolled
- * back.
+ * Since altering the two_phase option of subscriptions
+ * also leads to changing the slot option, this command
+ * cannot be rolled back. So prevent this if we are in a
+ * transaction block. In the opposite case, there is no
+ * need to prevent this because the logical replication
+ * worker already had the mechanism to alter the slot
+ * option at a convenient time.
*/
- PreventInTransactionBlock(isTopLevel, "ALTER SUBSCRIPTION ... SET (two_phase)");
+ if (!opts.twophase)
+ PreventInTransactionBlock(isTopLevel,
+ "ALTER SUBSCRIPTION ... SET (two_phase = off)");
/* Change system catalog acoordingly */
values[Anum_pg_subscription_subtwophasestate - 1] =
@@ -1547,14 +1556,25 @@ AlterSubscription(ParseState *pstate, AlterSubscriptionStmt *stmt,
}
/*
- * Try to acquire the connection necessary for altering slot.
+ * Check the need to alter the replication slot. Failover and two_phase
+ * options are controlled by both the publisher (as a slot option) and the
+ * subscriber (as a subscription option). The slot option must be altered
+ * only when changing "on" to "off". Because in opposite case, the logical
+ * replication worker already has the mechanism to do so at a convenient
+ * time.
+ */
+ update_failover = replaces[Anum_pg_subscription_subfailover - 1];
+ update_two_phase = (replaces[Anum_pg_subscription_subtwophasestate - 1] &&
+ !opts.twophase);
+
+ /*
+ * Try to acquire the connection necessary for altering slot, if needed.
*
* This has to be at the end because otherwise if there is an error while
* doing the database operations we won't be able to rollback altered
* slot.
*/
- if (replaces[Anum_pg_subscription_subfailover - 1] ||
- replaces[Anum_pg_subscription_subtwophasestate - 1])
+ if (update_failover || update_two_phase)
{
bool must_use_password;
char *err;
@@ -1574,7 +1594,9 @@ AlterSubscription(ParseState *pstate, AlterSubscriptionStmt *stmt,
PG_TRY();
{
- walrcv_alter_slot(wrconn, sub->slotname, opts.failover, opts.twophase);
+ walrcv_alter_slot(wrconn, sub->slotname,
+ update_failover ? &opts.failover : NULL,
+ update_two_phase ? &opts.twophase : NULL);
}
PG_FINALLY();
{
diff --git a/src/backend/replication/libpqwalreceiver/libpqwalreceiver.c b/src/backend/replication/libpqwalreceiver/libpqwalreceiver.c
index 998bbd517a..ff013aa987 100644
--- a/src/backend/replication/libpqwalreceiver/libpqwalreceiver.c
+++ b/src/backend/replication/libpqwalreceiver/libpqwalreceiver.c
@@ -80,7 +80,7 @@ static char *libpqrcv_create_slot(WalReceiverConn *conn,
CRSSnapshotAction snapshot_action,
XLogRecPtr *lsn);
static void libpqrcv_alter_slot(WalReceiverConn *conn, const char *slotname,
- bool failover, bool two_phase);
+ const bool *failover, const bool *two_phase);
static pid_t libpqrcv_get_backend_pid(WalReceiverConn *conn);
static WalRcvExecResult *libpqrcv_exec(WalReceiverConn *conn,
const char *query,
@@ -1121,16 +1121,27 @@ libpqrcv_create_slot(WalReceiverConn *conn, const char *slotname,
*/
static void
libpqrcv_alter_slot(WalReceiverConn *conn, const char *slotname,
- bool failover, bool two_phase)
+ const bool *failover, const bool *two_phase)
{
StringInfoData cmd;
PGresult *res;
initStringInfo(&cmd);
- appendStringInfo(&cmd, "ALTER_REPLICATION_SLOT %s ( FAILOVER %s, TWO_PHASE %s )",
- quote_identifier(slotname),
- failover ? "true" : "false",
- two_phase ? "true" : "false");
+ appendStringInfo(&cmd, "ALTER_REPLICATION_SLOT %s ( ",
+ quote_identifier(slotname));
+
+ if (failover)
+ appendStringInfo(&cmd, "FAILOVER %s",
+ *failover ? "true" : "false");
+
+ if (failover && two_phase)
+ appendStringInfo(&cmd, ", ");
+
+ if (two_phase)
+ appendStringInfo(&cmd, "TWO_PHASE %s",
+ *two_phase ? "true" : "false");
+
+ appendStringInfoString(&cmd, " );");
res = libpqrcv_PQexec(conn->streamConn, cmd.data);
pfree(cmd.data);
diff --git a/src/include/replication/walreceiver.h b/src/include/replication/walreceiver.h
index 31fa1257ec..7ffa5a58b3 100644
--- a/src/include/replication/walreceiver.h
+++ b/src/include/replication/walreceiver.h
@@ -377,8 +377,9 @@ typedef char *(*walrcv_create_slot_fn) (WalReceiverConn *conn,
*/
typedef void (*walrcv_alter_slot_fn) (WalReceiverConn *conn,
const char *slotname,
- bool failover,
- bool two_phase);
+ const bool *failover,
+ const bool *two_phase);
+
/*
* walrcv_get_backend_pid_fn
diff --git a/src/test/subscription/meson.build b/src/test/subscription/meson.build
index c591cd7d61..b4bd522c3d 100644
--- a/src/test/subscription/meson.build
+++ b/src/test/subscription/meson.build
@@ -40,6 +40,7 @@ tests += {
't/031_column_list.pl',
't/032_subscribe_use_index.pl',
't/033_run_as_table_owner.pl',
+ 't/099_twophase_added.pl',
't/100_bugs.pl',
],
},
diff --git a/src/test/subscription/t/099_twophase_added.pl b/src/test/subscription/t/099_twophase_added.pl
new file mode 100644
index 0000000000..db6cba1699
--- /dev/null
+++ b/src/test/subscription/t/099_twophase_added.pl
@@ -0,0 +1,96 @@
+# Copyright (c) 2024, PostgreSQL Global Development Group
+
+# Additional tests for altering two_phase option
+use strict;
+use warnings FATAL => 'all';
+use PostgreSQL::Test::Cluster;
+use PostgreSQL::Test::Utils;
+use Test::More;
+
+# Initialize publisher node
+my $node_publisher = PostgreSQL::Test::Cluster->new('publisher');
+$node_publisher->init(allows_streaming => 'logical');
+$node_publisher->append_conf('postgresql.conf',
+ qq(max_prepared_transactions = 10));
+$node_publisher->start;
+
+# Create subscriber node
+my $node_subscriber = PostgreSQL::Test::Cluster->new('subscriber');
+$node_subscriber->init;
+$node_subscriber->append_conf('postgresql.conf',
+ qq(max_prepared_transactions = 10
+ log_min_messages = debug1));
+$node_subscriber->start;
+
+# Define tables on both nodes
+$node_publisher->safe_psql('postgres',
+ "CREATE TABLE tab_full (a int PRIMARY KEY);");
+$node_subscriber->safe_psql('postgres',
+ "CREATE TABLE tab_full (a int PRIMARY KEY)");
+
+# Setup logical replication, with two_phase = "off"
+my $publisher_connstr = $node_publisher->connstr . ' dbname=postgres';
+$node_publisher->safe_psql('postgres',
+ "CREATE PUBLICATION pub FOR ALL TABLES");
+
+my $log_offset = -s $node_subscriber->logfile;
+
+$node_subscriber->safe_psql(
+ 'postgres', "
+ CREATE SUBSCRIPTION regress_sub
+ CONNECTION '$publisher_connstr' PUBLICATION pub
+ WITH (two_phase = off, copy_data = off, failover = off)");
+
+# Verify the started worker recognized two_phase was disabled
+$node_subscriber->wait_for_log(
+ 'logical replication apply worker for subscription "regress_sub" two_phase is DISABLED', $log_offset);
+
+#####################
+# Check the case that prepared transactions exist on the publisher node.
+#
+# Since the two_phase is "off", then normally, this PREPARE will do nothing
+# until the COMMIT PREPARED, but in this test, we toggle the two_phase to "on"
+# again before the COMMIT PREPARED happens.
+
+# Prepare a transaction to insert some tuples into the table
+$node_publisher->safe_psql(
+ 'postgres', "
+ BEGIN;
+ INSERT INTO tab_full VALUES (generate_series(1, 5));
+ PREPARE TRANSACTION 'test_prepared_tab_full';");
+
+$node_publisher->wait_for_catchup('regress_sub');
+
+# Verify the prepared transaction is not yet replicated to the subscriber
+# because two_phase is set to "off".
+my $result = $node_subscriber->safe_psql('postgres',
+ "SELECT count(*) FROM pg_prepared_xacts;");
+is($result, q(0), "transaction is not prepared on subscriber");
+
+$log_offset = -s $node_subscriber->logfile;
+
+# Toggle the two_phase to "on" *before* the COMMIT PREPARED. Since we are the
+# special path for the case where both two_phase and failover are altered, it
+# is also set to "on".
+$node_subscriber->safe_psql(
+ 'postgres', "
+ ALTER SUBSCRIPTION regress_sub DISABLE;
+ ALTER SUBSCRIPTION regress_sub SET (two_phase = on, failover = on);
+ ALTER SUBSCRIPTION regress_sub ENABLE;");
+
+# Verify the started worker recognized two_phase was enabled
+$node_subscriber->wait_for_log(
+ 'logical replication apply worker for subscription "regress_sub" two_phase is ENABLED', $log_offset);
+
+# And do COMMIT PREPARED the prepared transaction
+$node_publisher->safe_psql('postgres',
+ "COMMIT PREPARED 'test_prepared_tab_full';");
+$node_publisher->wait_for_catchup('regress_sub');
+
+# Verify inserted tuples are replicated
+$result = $node_subscriber->safe_psql('postgres',
+ "SELECT count(*) FROM tab_full;");
+is($result, q(5),
+ "prepared transactions done before altering can be replicated");
+
+done_testing();
--
2.43.0
[application/octet-stream] v9-0003-Abort-prepared-transactions-while-altering-two_ph.patch (8.8K, ../../OSBPR01MB2552FEA48D265EA278AA9F7AF5E22@OSBPR01MB2552.jpnprd01.prod.outlook.com/4-v9-0003-Abort-prepared-transactions-while-altering-two_ph.patch)
download | inline diff:
From 1f4ac6ef248dda223ea451f74c13d2db73d72f75 Mon Sep 17 00:00:00 2001
From: Hayato Kuroda <[email protected]>
Date: Mon, 8 Apr 2024 12:39:12 +0000
Subject: [PATCH v9 3/4] Abort prepared transactions while altering two_phase
to off
If we alter the two_phase parameter from "on" to "off" and there are prepared
transactions on the subscriber, they won't be resolved. To avoid this issue, we
allow the backend to abort all prepared transactions while altering the
subscription.
---
doc/src/sgml/ref/alter_subscription.sgml | 11 ++++-
src/backend/access/transam/twophase.c | 17 +++----
src/backend/commands/subscriptioncmds.c | 48 ++++++++++++-------
src/include/access/twophase.h | 3 +-
src/test/subscription/t/099_twophase_added.pl | 45 +++++++++++++++++
5 files changed, 93 insertions(+), 31 deletions(-)
diff --git a/doc/src/sgml/ref/alter_subscription.sgml b/doc/src/sgml/ref/alter_subscription.sgml
index 0c2894a94e..74728a503d 100644
--- a/doc/src/sgml/ref/alter_subscription.sgml
+++ b/doc/src/sgml/ref/alter_subscription.sgml
@@ -233,8 +233,6 @@ ALTER SUBSCRIPTION <replaceable class="parameter">name</replaceable> RENAME TO <
<link linkend="sql-createsubscription-params-with-failover"><literal>failover</literal></link>, and
<link linkend="sql-createsubscription-params-with-two-phase"><literal>two_phase</literal></link>.
Only a superuser can set <literal>password_required = false</literal>.
- The <literal>two_phase</literal> parameter can only be altered when the
- subscription is disabled.
</para>
<para>
@@ -256,6 +254,15 @@ ALTER SUBSCRIPTION <replaceable class="parameter">name</replaceable> RENAME TO <
<link linkend="sql-createsubscription-params-with-failover"><literal>failover</literal></link>
option is enabled.
</para>
+
+ <para>
+ The <literal>two_phase</literal> parameter can only be altered when the
+ subscription is disabled. When altering the parameter from <literal>on</literal>
+ to <literal>off</literal>, the backend process checks for any incomplete
+ prepared transactions done by the logical replication worker (from when
+ <literal>two_phase</literal> parameter was still <literal>on</literal>)
+ and, if any are found, those are aborted.
+ </para>
</listitem>
</varlistentry>
diff --git a/src/backend/access/transam/twophase.c b/src/backend/access/transam/twophase.c
index 66fa591eb5..f384bd8c0a 100644
--- a/src/backend/access/transam/twophase.c
+++ b/src/backend/access/transam/twophase.c
@@ -2720,13 +2720,13 @@ IsTwoPhaseTransactionGidForSubid(Oid subid, char *gid)
}
/*
- * LookupGXactBySubid
- * Check if the prepared transaction done by apply worker exists.
+ * GetGidListBySubid
+ * Get a list of GIDs which is PREPARE'd by the given subscription.
*/
-bool
-LookupGXactBySubid(Oid subid)
+List *
+GetGidListBySubid(Oid subid)
{
- bool found = false;
+ List *list = NIL;
LWLockAcquire(TwoPhaseStateLock, LW_SHARED);
for (int i = 0; i < TwoPhaseState->numPrepXacts; i++)
@@ -2736,11 +2736,8 @@ LookupGXactBySubid(Oid subid)
/* Ignore not-yet-valid GIDs. */
if (gxact->valid &&
IsTwoPhaseTransactionGidForSubid(subid, gxact->gid))
- {
- found = true;
- break;
- }
+ list = lappend(list, pstrdup(gxact->gid));
}
LWLockRelease(TwoPhaseStateLock);
- return found;
+ return list;
}
diff --git a/src/backend/commands/subscriptioncmds.c b/src/backend/commands/subscriptioncmds.c
index 4021defcea..97bd11bc4a 100644
--- a/src/backend/commands/subscriptioncmds.c
+++ b/src/backend/commands/subscriptioncmds.c
@@ -1176,30 +1176,42 @@ AlterSubscription(ParseState *pstate, AlterSubscriptionStmt *stmt,
logicalrep_workers_stop(subid);
/*
- * two_phase cannot be disabled if there are any
- * uncommitted prepared transactions present.
+ * If two_phase was enabled, there is a possibility that
+ * transactions have already been PREPARE'd. They must be
+ * checked and rolled back.
*/
- if (!opts.twophase &&
- form->subtwophasestate == LOGICALREP_TWOPHASE_STATE_ENABLED &&
- LookupGXactBySubid(subid))
- ereport(ERROR,
- (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
- errmsg("cannot disable two_phase when uncommitted prepared transactions present"),
- errhint("Resolve these transactions and try again")));
- /*
- * Since altering the two_phase option of subscriptions
- * also leads to changing the slot option, this command
- * cannot be rolled back. So prevent this if we are in a
- * transaction block. In the opposite case, there is no
- * need to prevent this because the logical replication
- * worker already had the mechanism to alter the slot
- * option at a convenient time.
- */
if (!opts.twophase)
+ {
+ List *prepared_xacts;
+
+ /*
+ * Since altering the two_phase option of subscriptions
+ * also leads to changing the slot option, this command
+ * cannot be rolled back. So prevent this if we are in a
+ * transaction block. In the opposite case, there is no
+ * need to prevent this because the logical replication
+ * worker already had the mechanism to alter the slot
+ * option at a convenient time.
+ */
PreventInTransactionBlock(isTopLevel,
"ALTER SUBSCRIPTION ... SET (two_phase = off)");
+ /*
+ * To prevent prepared transactions from being
+ * isolated, they must manually be aborted.
+ */
+ if (sub->twophasestate == LOGICALREP_TWOPHASE_STATE_ENABLED &&
+ (prepared_xacts = GetGidListBySubid(subid)) != NIL)
+ {
+ /* Abort all listed transactions */
+ foreach_ptr(char, gid, prepared_xacts)
+ FinishPreparedTransaction(gid, false);
+
+ list_free_deep(prepared_xacts);
+ }
+ }
+
/* Change system catalog acoordingly */
values[Anum_pg_subscription_subtwophasestate - 1] =
CharGetDatum(opts.twophase ?
diff --git a/src/include/access/twophase.h b/src/include/access/twophase.h
index d37e06fdee..f7a5cf0c12 100644
--- a/src/include/access/twophase.h
+++ b/src/include/access/twophase.h
@@ -18,6 +18,7 @@
#include "access/xlogdefs.h"
#include "datatype/timestamp.h"
#include "storage/lock.h"
+#include "nodes/pg_list.h"
/*
* GlobalTransactionData is defined in twophase.c; other places have no
@@ -65,6 +66,6 @@ extern bool LookupGXact(const char *gid, XLogRecPtr prepare_end_lsn,
extern void TwoPhaseTransactionGid(Oid subid, TransactionId xid, char *gid,
int szgid);
-extern bool LookupGXactBySubid(Oid subid);
+extern List *GetGidListBySubid(Oid subid);
#endif /* TWOPHASE_H */
diff --git a/src/test/subscription/t/099_twophase_added.pl b/src/test/subscription/t/099_twophase_added.pl
index db6cba1699..9cc1ca9167 100644
--- a/src/test/subscription/t/099_twophase_added.pl
+++ b/src/test/subscription/t/099_twophase_added.pl
@@ -93,4 +93,49 @@ $result = $node_subscriber->safe_psql('postgres',
is($result, q(5),
"prepared transactions done before altering can be replicated");
+#####################
+# Check the case that prepared transactions exist on the subscriber node
+#
+# If the two_phase is altering from "on" to "off" and there are prepared
+# transactions on the subscriber, they must be aborted. This test checks it.
+
+# Prepare a transaction to insert some tuples into the table
+$node_publisher->safe_psql(
+ 'postgres', "
+ BEGIN;
+ INSERT INTO tab_full VALUES (generate_series(6, 10));
+ PREPARE TRANSACTION 'test_prepared_tab_full';");
+
+$node_publisher->wait_for_catchup('regress_sub');
+
+# Verify the prepared transaction has been replicated to the subscriber because
+# two_phase is set to "on".
+$result = $node_subscriber->safe_psql('postgres',
+ "SELECT count(*) FROM pg_prepared_xacts;");
+is($result, q(1), "transaction has been prepared on subscriber");
+
+# Toggle the two_phase to "off" before the COMMIT PREPARED
+$node_subscriber->safe_psql(
+ 'postgres', "
+ ALTER SUBSCRIPTION regress_sub DISABLE;
+ ALTER SUBSCRIPTION regress_sub SET (two_phase = off);
+ ALTER SUBSCRIPTION regress_sub ENABLE;");
+
+# Verify any prepared transactions are aborted because two_phase is changed to
+# "off".
+$result = $node_subscriber->safe_psql('postgres',
+ "SELECT count(*) FROM pg_prepared_xacts;");
+is($result, q(0), "prepared transaction done by worker is aborted");
+
+# Do COMMIT PREPARED the prepared transaction
+$node_publisher->safe_psql( 'postgres',
+ "COMMIT PREPARED 'test_prepared_tab_full';");
+$node_publisher->wait_for_catchup('regress_sub');
+
+# Verify inserted tuples are replicated
+$result = $node_subscriber->safe_psql('postgres',
+ "SELECT count(10) FROM tab_full;");
+is($result, q(10),
+ "prepared transactions on publisher can be replicated");
+
done_testing();
--
2.43.0
[application/octet-stream] v9-0004-Add-force_alter-option-for-ALTER-SUBSCRIPTION-.-S.patch (56.7K, ../../OSBPR01MB2552FEA48D265EA278AA9F7AF5E22@OSBPR01MB2552.jpnprd01.prod.outlook.com/5-v9-0004-Add-force_alter-option-for-ALTER-SUBSCRIPTION-.-S.patch)
download | inline diff:
From 1dd9ac0ee519b63881bdd12aba1a8782662b1188 Mon Sep 17 00:00:00 2001
From: Hayato Kuroda <[email protected]>
Date: Fri, 19 Apr 2024 11:03:19 +0000
Subject: [PATCH v9 4/4] Add force_alter option for ALTER SUBSCRIPTION ... SET
command
Previously, all prepared transactions on the standby were rolled back when
toggling two_phase from "on" to "off". However, this operation may not be
expected by users. To ensure users understand what happens, we added the
"force_alter" parameter. When two_phase is toggling to "off", and there are
prepared transactions, they will be aborted only when "force_alter" is set to
true. Otherwise, an ERROR occurs.
---
doc/src/sgml/catalogs.sgml | 10 ++
doc/src/sgml/ref/alter_subscription.sgml | 16 +-
doc/src/sgml/ref/create_subscription.sgml | 18 +++
src/backend/catalog/pg_subscription.c | 1 +
src/backend/catalog/system_views.sql | 2 +-
src/backend/commands/subscriptioncmds.c | 45 +++++-
src/bin/pg_dump/pg_dump.c | 15 ++
src/bin/pg_dump/pg_dump.h | 1 +
src/bin/psql/describe.c | 7 +-
src/include/catalog/pg_subscription.h | 6 +
src/test/regress/expected/subscription.out | 152 +++++++++---------
src/test/subscription/t/099_twophase_added.pl | 43 +++--
12 files changed, 216 insertions(+), 100 deletions(-)
diff --git a/doc/src/sgml/catalogs.sgml b/doc/src/sgml/catalogs.sgml
index b530c030f0..6a7b2faa66 100644
--- a/doc/src/sgml/catalogs.sgml
+++ b/doc/src/sgml/catalogs.sgml
@@ -8046,6 +8046,16 @@ SCRAM-SHA-256$<replaceable><iteration count></replaceable>:<replaceable>&l
</para></entry>
</row>
+ <row>
+ <entry role="catalog_table_entry"><para role="column_definition">
+ <structfield>subforcealter</structfield> <type>bool</type>
+ </para>
+ <para>
+ If true, the subscription can be altered <literal>two_phase</literal>
+ option, even if there are prepared transactions
+ </para></entry>
+ </row>
+
<row>
<entry role="catalog_table_entry"><para role="column_definition">
<structfield>subconninfo</structfield> <type>text</type>
diff --git a/doc/src/sgml/ref/alter_subscription.sgml b/doc/src/sgml/ref/alter_subscription.sgml
index 74728a503d..e7c363a1c9 100644
--- a/doc/src/sgml/ref/alter_subscription.sgml
+++ b/doc/src/sgml/ref/alter_subscription.sgml
@@ -230,9 +230,12 @@ ALTER SUBSCRIPTION <replaceable class="parameter">name</replaceable> RENAME TO <
<link linkend="sql-createsubscription-params-with-password-required"><literal>password_required</literal></link>,
<link linkend="sql-createsubscription-params-with-run-as-owner"><literal>run_as_owner</literal></link>,
<link linkend="sql-createsubscription-params-with-origin"><literal>origin</literal></link>,
- <link linkend="sql-createsubscription-params-with-failover"><literal>failover</literal></link>, and
- <link linkend="sql-createsubscription-params-with-two-phase"><literal>two_phase</literal></link>.
+ <link linkend="sql-createsubscription-params-with-failover"><literal>failover</literal></link>,
+ <link linkend="sql-createsubscription-params-with-two-phase"><literal>two_phase</literal></link>, and
+ <link linkend="sql-createsubscription-params-with-force-alter"><literal>force_alter</literal></link>
Only a superuser can set <literal>password_required = false</literal>.
+ The <literal>two_phase</literal> parameter can only be altered when the
+ subscription is disabled.
</para>
<para>
@@ -254,15 +257,6 @@ ALTER SUBSCRIPTION <replaceable class="parameter">name</replaceable> RENAME TO <
<link linkend="sql-createsubscription-params-with-failover"><literal>failover</literal></link>
option is enabled.
</para>
-
- <para>
- The <literal>two_phase</literal> parameter can only be altered when the
- subscription is disabled. When altering the parameter from <literal>on</literal>
- to <literal>off</literal>, the backend process checks for any incomplete
- prepared transactions done by the logical replication worker (from when
- <literal>two_phase</literal> parameter was still <literal>on</literal>)
- and, if any are found, those are aborted.
- </para>
</listitem>
</varlistentry>
diff --git a/doc/src/sgml/ref/create_subscription.sgml b/doc/src/sgml/ref/create_subscription.sgml
index 740b7d9421..a4f30b4453 100644
--- a/doc/src/sgml/ref/create_subscription.sgml
+++ b/doc/src/sgml/ref/create_subscription.sgml
@@ -428,6 +428,24 @@ CREATE SUBSCRIPTION <replaceable class="parameter">subscription_name</replaceabl
</para>
</listitem>
</varlistentry>
+
+ <varlistentry id="sql-createsubscription-params-with-force-alter">
+ <term><literal>force_alter</literal> (<type>boolean</type>)</term>
+ <listitem>
+ <para>
+ Specifies whether the subscription can be altered
+ <literal>two_phase</literal> option, even if there are prepared
+ transactions. If specified, the backend process checks for any
+ incomplete prepared transactions done by the logical replication
+ worker (from when <literal>two_phase</literal> parameter was still
+ <literal>on</literal>), if any are found, those are aborted.
+ Otherwise, Altering the parameter from <literal>on</literal> to
+ <literal>off</literal> will give an error when there are prepared
+ transactions done by the logical replication worker.
+ The default is <literal>false</literal>.
+ </para>
+ </listitem>
+ </varlistentry>
</variablelist></para>
</listitem>
diff --git a/src/backend/catalog/pg_subscription.c b/src/backend/catalog/pg_subscription.c
index 9efc9159f2..b568fe3470 100644
--- a/src/backend/catalog/pg_subscription.c
+++ b/src/backend/catalog/pg_subscription.c
@@ -72,6 +72,7 @@ GetSubscription(Oid subid, bool missing_ok)
sub->passwordrequired = subform->subpasswordrequired;
sub->runasowner = subform->subrunasowner;
sub->failover = subform->subfailover;
+ sub->forcealter = subform->subforcealter;
/* Get conninfo */
datum = SysCacheGetAttrNotNull(SUBSCRIPTIONOID,
diff --git a/src/backend/catalog/system_views.sql b/src/backend/catalog/system_views.sql
index 53047cab5f..de3d3d8f3e 100644
--- a/src/backend/catalog/system_views.sql
+++ b/src/backend/catalog/system_views.sql
@@ -1358,7 +1358,7 @@ REVOKE ALL ON pg_replication_origin_status FROM public;
REVOKE ALL ON pg_subscription FROM public;
GRANT SELECT (oid, subdbid, subskiplsn, subname, subowner, subenabled,
subbinary, substream, subtwophasestate, subdisableonerr,
- subpasswordrequired, subrunasowner, subfailover,
+ subpasswordrequired, subrunasowner, subfailover, subforcealter,
subslotname, subsynccommit, subpublications, suborigin)
ON pg_subscription TO public;
diff --git a/src/backend/commands/subscriptioncmds.c b/src/backend/commands/subscriptioncmds.c
index 97bd11bc4a..7900bb1b28 100644
--- a/src/backend/commands/subscriptioncmds.c
+++ b/src/backend/commands/subscriptioncmds.c
@@ -73,6 +73,7 @@
#define SUBOPT_FAILOVER 0x00002000
#define SUBOPT_LSN 0x00004000
#define SUBOPT_ORIGIN 0x00008000
+#define SUBOPT_FORCE_ALTER 0x00010000
/* check if the 'val' has 'bits' set */
#define IsSet(val, bits) (((val) & (bits)) == (bits))
@@ -100,6 +101,7 @@ typedef struct SubOpts
bool failover;
char *origin;
XLogRecPtr lsn;
+ bool force_alter;
} SubOpts;
static List *fetch_table_list(WalReceiverConn *wrconn, List *publications);
@@ -162,6 +164,8 @@ parse_subscription_options(ParseState *pstate, List *stmt_options,
opts->failover = false;
if (IsSet(supported_opts, SUBOPT_ORIGIN))
opts->origin = pstrdup(LOGICALREP_ORIGIN_ANY);
+ if (IsSet(supported_opts, SUBOPT_FORCE_ALTER))
+ opts->force_alter = false;
/* Parse options */
foreach(lc, stmt_options)
@@ -367,6 +371,15 @@ parse_subscription_options(ParseState *pstate, List *stmt_options,
opts->specified_opts |= SUBOPT_LSN;
opts->lsn = lsn;
}
+ else if (IsSet(supported_opts, SUBOPT_FORCE_ALTER) &&
+ strcmp(defel->defname, "force_alter") == 0)
+ {
+ if (IsSet(opts->specified_opts, SUBOPT_FORCE_ALTER))
+ errorConflictingDefElem(defel, pstate);
+
+ opts->specified_opts |= SUBOPT_FORCE_ALTER;
+ opts->force_alter = defGetBoolean(defel);
+ }
else
ereport(ERROR,
(errcode(ERRCODE_SYNTAX_ERROR),
@@ -604,7 +617,8 @@ CreateSubscription(ParseState *pstate, CreateSubscriptionStmt *stmt,
SUBOPT_SYNCHRONOUS_COMMIT | SUBOPT_BINARY |
SUBOPT_STREAMING | SUBOPT_TWOPHASE_COMMIT |
SUBOPT_DISABLE_ON_ERR | SUBOPT_PASSWORD_REQUIRED |
- SUBOPT_RUN_AS_OWNER | SUBOPT_FAILOVER | SUBOPT_ORIGIN);
+ SUBOPT_RUN_AS_OWNER | SUBOPT_FAILOVER | SUBOPT_ORIGIN |
+ SUBOPT_FORCE_ALTER);
parse_subscription_options(pstate, stmt->options, supported_opts, &opts);
/*
@@ -711,6 +725,7 @@ CreateSubscription(ParseState *pstate, CreateSubscriptionStmt *stmt,
values[Anum_pg_subscription_subpasswordrequired - 1] = BoolGetDatum(opts.passwordrequired);
values[Anum_pg_subscription_subrunasowner - 1] = BoolGetDatum(opts.runasowner);
values[Anum_pg_subscription_subfailover - 1] = BoolGetDatum(opts.failover);
+ values[Anum_pg_subscription_subforcealter] = BoolGetDatum(opts.force_alter);
values[Anum_pg_subscription_subconninfo - 1] =
CStringGetTextDatum(conninfo);
if (opts.slot_name)
@@ -1150,7 +1165,7 @@ AlterSubscription(ParseState *pstate, AlterSubscriptionStmt *stmt,
SUBOPT_DISABLE_ON_ERR |
SUBOPT_PASSWORD_REQUIRED |
SUBOPT_RUN_AS_OWNER | SUBOPT_FAILOVER |
- SUBOPT_ORIGIN);
+ SUBOPT_ORIGIN | SUBOPT_FORCE_ALTER);
parse_subscription_options(pstate, stmt->options,
supported_opts, &opts);
@@ -1204,6 +1219,32 @@ AlterSubscription(ParseState *pstate, AlterSubscriptionStmt *stmt,
if (sub->twophasestate == LOGICALREP_TWOPHASE_STATE_ENABLED &&
(prepared_xacts = GetGidListBySubid(subid)) != NIL)
{
+ /*
+ * Abort prepared transactions only if
+ * 'force_alter' option is true. Otherwise raise
+ * an ERROR.
+ */
+ if (IsSet(opts.specified_opts, SUBOPT_FORCE_ALTER))
+ {
+ if (!opts.force_alter)
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("cannot alter %s when there are prepared transactions",
+ "two_phase = off"),
+ errhint("Resolve these transactions or set %s, and then try again.",
+ "force_alter = true")));
+ }
+ else
+ {
+ if (!sub->forcealter)
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("cannot alter %s when there are prepared transactions",
+ "two_phase = off"),
+ errhint("Resolve these transactions or set %s, and then try again.",
+ "force_alter = true")));
+ }
+
/* Abort all listed transactions */
foreach_ptr(char, gid, prepared_xacts)
FinishPreparedTransaction(gid, false);
diff --git a/src/bin/pg_dump/pg_dump.c b/src/bin/pg_dump/pg_dump.c
index 5f005a2f14..75b6d1693e 100644
--- a/src/bin/pg_dump/pg_dump.c
+++ b/src/bin/pg_dump/pg_dump.c
@@ -4739,6 +4739,7 @@ getSubscriptions(Archive *fout)
int i_suboriginremotelsn;
int i_subenabled;
int i_subfailover;
+ int i_subforcealter;
int i,
ntups;
@@ -4816,6 +4817,14 @@ getSubscriptions(Archive *fout)
appendPQExpBuffer(query,
" false AS subfailover\n");
+ if (fout->remoteVersion >= 170000)
+ appendPQExpBufferStr(query,
+ " s.subforcealter\n");
+ else
+ appendPQExpBuffer(query,
+ " false AS subforcealter\n");
+
+
appendPQExpBufferStr(query,
"FROM pg_subscription s\n");
@@ -4854,6 +4863,7 @@ getSubscriptions(Archive *fout)
i_suboriginremotelsn = PQfnumber(res, "suboriginremotelsn");
i_subenabled = PQfnumber(res, "subenabled");
i_subfailover = PQfnumber(res, "subfailover");
+ i_subforcealter = PQfnumber(res, "subforcealter");
subinfo = pg_malloc(ntups * sizeof(SubscriptionInfo));
@@ -4900,6 +4910,8 @@ getSubscriptions(Archive *fout)
pg_strdup(PQgetvalue(res, i, i_subenabled));
subinfo[i].subfailover =
pg_strdup(PQgetvalue(res, i, i_subfailover));
+ subinfo[i].subforcealter =
+ pg_strdup(PQgetvalue(res, i, i_subforcealter));
/* Decide whether we want to dump it */
selectDumpableObject(&(subinfo[i].dobj), fout);
@@ -5140,6 +5152,9 @@ dumpSubscription(Archive *fout, const SubscriptionInfo *subinfo)
if (strcmp(subinfo->subfailover, "t") == 0)
appendPQExpBufferStr(query, ", failover = true");
+ if (strcmp(subinfo->subforcealter, "t") == 0)
+ appendPQExpBufferStr(query, ", force_alter = true");
+
if (strcmp(subinfo->subsynccommit, "off") != 0)
appendPQExpBuffer(query, ", synchronous_commit = %s", fmtId(subinfo->subsynccommit));
diff --git a/src/bin/pg_dump/pg_dump.h b/src/bin/pg_dump/pg_dump.h
index 2a7c5873a0..0e85ee311b 100644
--- a/src/bin/pg_dump/pg_dump.h
+++ b/src/bin/pg_dump/pg_dump.h
@@ -677,6 +677,7 @@ typedef struct _SubscriptionInfo
char *suborigin;
char *suboriginremotelsn;
char *subfailover;
+ char *subforcealter;
} SubscriptionInfo;
/*
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index 4a9ee4a54d..86f099ba57 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -6581,7 +6581,7 @@ describeSubscriptions(const char *pattern, bool verbose)
printQueryOpt myopt = pset.popt;
static const bool translate_columns[] = {false, false, false, false,
false, false, false, false, false, false, false, false, false, false,
- false};
+ false, false};
if (pset.sversion < 100000)
{
@@ -6650,6 +6650,11 @@ describeSubscriptions(const char *pattern, bool verbose)
", subfailover AS \"%s\"\n",
gettext_noop("Failover"));
+ if (pset.sversion >= 170000)
+ appendPQExpBuffer(&buf,
+ ", subforcealter AS \"%s\"\n",
+ gettext_noop("Force_alter"));
+
appendPQExpBuffer(&buf,
", subsynccommit AS \"%s\"\n"
", subconninfo AS \"%s\"\n",
diff --git a/src/include/catalog/pg_subscription.h b/src/include/catalog/pg_subscription.h
index 0aa14ec4a2..208e540f80 100644
--- a/src/include/catalog/pg_subscription.h
+++ b/src/include/catalog/pg_subscription.h
@@ -98,6 +98,9 @@ CATALOG(pg_subscription,6100,SubscriptionRelationId) BKI_SHARED_RELATION BKI_ROW
* slots) in the upstream database are enabled
* to be synchronized to the standbys. */
+ bool subforcealter; /* True if we allow to drop prepared transactions
+ * when altering two_phase "on"->"off". */
+
#ifdef CATALOG_VARLEN /* variable-length fields start here */
/* Connection string to the publisher */
text subconninfo BKI_FORCE_NOT_NULL;
@@ -151,6 +154,9 @@ typedef struct Subscription
* (i.e. the main slot and the table sync
* slots) in the upstream database are enabled
* to be synchronized to the standbys. */
+ bool forcealter; /* True if we allow to drop prepared
+ * transactions when altering two_phase
+ * "on"->"off". */
char *conninfo; /* Connection string to the publisher */
char *slotname; /* Name of the replication slot */
char *synccommit; /* Synchronous commit setting for worker */
diff --git a/src/test/regress/expected/subscription.out b/src/test/regress/expected/subscription.out
index 51fa4b9690..5100309d35 100644
--- a/src/test/regress/expected/subscription.out
+++ b/src/test/regress/expected/subscription.out
@@ -116,18 +116,18 @@ CREATE SUBSCRIPTION regress_testsub4 CONNECTION 'dbname=regress_doesnotexist' PU
WARNING: subscription was created, but is not connected
HINT: To initiate replication, you must manually create the replication slot, enable the subscription, and refresh the subscription.
\dRs+ regress_testsub4
- List of subscriptions
- Name | Owner | Enabled | Publication | Binary | Streaming | Two-phase commit | Disable on error | Origin | Password required | Run as owner? | Failover | Synchronous commit | Conninfo | Skip LSN
-------------------+---------------------------+---------+-------------+--------+-----------+------------------+------------------+--------+-------------------+---------------+----------+--------------------+-----------------------------+----------
- regress_testsub4 | regress_subscription_user | f | {testpub} | f | off | d | f | none | t | f | f | off | dbname=regress_doesnotexist | 0/0
+ List of subscriptions
+ Name | Owner | Enabled | Publication | Binary | Streaming | Two-phase commit | Disable on error | Origin | Password required | Run as owner? | Failover | Force_alter | Synchronous commit | Conninfo | Skip LSN
+------------------+---------------------------+---------+-------------+--------+-----------+------------------+------------------+--------+-------------------+---------------+----------+-------------+--------------------+-----------------------------+----------
+ regress_testsub4 | regress_subscription_user | f | {testpub} | f | off | d | f | none | t | f | f | f | off | dbname=regress_doesnotexist | 0/0
(1 row)
ALTER SUBSCRIPTION regress_testsub4 SET (origin = any);
\dRs+ regress_testsub4
- List of subscriptions
- Name | Owner | Enabled | Publication | Binary | Streaming | Two-phase commit | Disable on error | Origin | Password required | Run as owner? | Failover | Synchronous commit | Conninfo | Skip LSN
-------------------+---------------------------+---------+-------------+--------+-----------+------------------+------------------+--------+-------------------+---------------+----------+--------------------+-----------------------------+----------
- regress_testsub4 | regress_subscription_user | f | {testpub} | f | off | d | f | any | t | f | f | off | dbname=regress_doesnotexist | 0/0
+ List of subscriptions
+ Name | Owner | Enabled | Publication | Binary | Streaming | Two-phase commit | Disable on error | Origin | Password required | Run as owner? | Failover | Force_alter | Synchronous commit | Conninfo | Skip LSN
+------------------+---------------------------+---------+-------------+--------+-----------+------------------+------------------+--------+-------------------+---------------+----------+-------------+--------------------+-----------------------------+----------
+ regress_testsub4 | regress_subscription_user | f | {testpub} | f | off | d | f | any | t | f | f | f | off | dbname=regress_doesnotexist | 0/0
(1 row)
DROP SUBSCRIPTION regress_testsub3;
@@ -145,10 +145,10 @@ ALTER SUBSCRIPTION regress_testsub CONNECTION 'foobar';
ERROR: invalid connection string syntax: missing "=" after "foobar" in connection info string
\dRs+
- List of subscriptions
- Name | Owner | Enabled | Publication | Binary | Streaming | Two-phase commit | Disable on error | Origin | Password required | Run as owner? | Failover | Synchronous commit | Conninfo | Skip LSN
------------------+---------------------------+---------+-------------+--------+-----------+------------------+------------------+--------+-------------------+---------------+----------+--------------------+-----------------------------+----------
- regress_testsub | regress_subscription_user | f | {testpub} | f | off | d | f | any | t | f | f | off | dbname=regress_doesnotexist | 0/0
+ List of subscriptions
+ Name | Owner | Enabled | Publication | Binary | Streaming | Two-phase commit | Disable on error | Origin | Password required | Run as owner? | Failover | Force_alter | Synchronous commit | Conninfo | Skip LSN
+-----------------+---------------------------+---------+-------------+--------+-----------+------------------+------------------+--------+-------------------+---------------+----------+-------------+--------------------+-----------------------------+----------
+ regress_testsub | regress_subscription_user | f | {testpub} | f | off | d | f | any | t | f | f | f | off | dbname=regress_doesnotexist | 0/0
(1 row)
ALTER SUBSCRIPTION regress_testsub SET PUBLICATION testpub2, testpub3 WITH (refresh = false);
@@ -157,10 +157,10 @@ ALTER SUBSCRIPTION regress_testsub SET (slot_name = 'newname');
ALTER SUBSCRIPTION regress_testsub SET (password_required = false);
ALTER SUBSCRIPTION regress_testsub SET (run_as_owner = true);
\dRs+
- List of subscriptions
- Name | Owner | Enabled | Publication | Binary | Streaming | Two-phase commit | Disable on error | Origin | Password required | Run as owner? | Failover | Synchronous commit | Conninfo | Skip LSN
------------------+---------------------------+---------+---------------------+--------+-----------+------------------+------------------+--------+-------------------+---------------+----------+--------------------+------------------------------+----------
- regress_testsub | regress_subscription_user | f | {testpub2,testpub3} | f | off | d | f | any | f | t | f | off | dbname=regress_doesnotexist2 | 0/0
+ List of subscriptions
+ Name | Owner | Enabled | Publication | Binary | Streaming | Two-phase commit | Disable on error | Origin | Password required | Run as owner? | Failover | Force_alter | Synchronous commit | Conninfo | Skip LSN
+-----------------+---------------------------+---------+---------------------+--------+-----------+------------------+------------------+--------+-------------------+---------------+----------+-------------+--------------------+------------------------------+----------
+ regress_testsub | regress_subscription_user | f | {testpub2,testpub3} | f | off | d | f | any | f | t | f | f | off | dbname=regress_doesnotexist2 | 0/0
(1 row)
ALTER SUBSCRIPTION regress_testsub SET (password_required = true);
@@ -176,10 +176,10 @@ ERROR: unrecognized subscription parameter: "create_slot"
-- ok
ALTER SUBSCRIPTION regress_testsub SKIP (lsn = '0/12345');
\dRs+
- List of subscriptions
- Name | Owner | Enabled | Publication | Binary | Streaming | Two-phase commit | Disable on error | Origin | Password required | Run as owner? | Failover | Synchronous commit | Conninfo | Skip LSN
------------------+---------------------------+---------+---------------------+--------+-----------+------------------+------------------+--------+-------------------+---------------+----------+--------------------+------------------------------+----------
- regress_testsub | regress_subscription_user | f | {testpub2,testpub3} | f | off | d | f | any | t | f | f | off | dbname=regress_doesnotexist2 | 0/12345
+ List of subscriptions
+ Name | Owner | Enabled | Publication | Binary | Streaming | Two-phase commit | Disable on error | Origin | Password required | Run as owner? | Failover | Force_alter | Synchronous commit | Conninfo | Skip LSN
+-----------------+---------------------------+---------+---------------------+--------+-----------+------------------+------------------+--------+-------------------+---------------+----------+-------------+--------------------+------------------------------+----------
+ regress_testsub | regress_subscription_user | f | {testpub2,testpub3} | f | off | d | f | any | t | f | f | f | off | dbname=regress_doesnotexist2 | 0/12345
(1 row)
-- ok - with lsn = NONE
@@ -188,10 +188,10 @@ ALTER SUBSCRIPTION regress_testsub SKIP (lsn = NONE);
ALTER SUBSCRIPTION regress_testsub SKIP (lsn = '0/0');
ERROR: invalid WAL location (LSN): 0/0
\dRs+
- List of subscriptions
- Name | Owner | Enabled | Publication | Binary | Streaming | Two-phase commit | Disable on error | Origin | Password required | Run as owner? | Failover | Synchronous commit | Conninfo | Skip LSN
------------------+---------------------------+---------+---------------------+--------+-----------+------------------+------------------+--------+-------------------+---------------+----------+--------------------+------------------------------+----------
- regress_testsub | regress_subscription_user | f | {testpub2,testpub3} | f | off | d | f | any | t | f | f | off | dbname=regress_doesnotexist2 | 0/0
+ List of subscriptions
+ Name | Owner | Enabled | Publication | Binary | Streaming | Two-phase commit | Disable on error | Origin | Password required | Run as owner? | Failover | Force_alter | Synchronous commit | Conninfo | Skip LSN
+-----------------+---------------------------+---------+---------------------+--------+-----------+------------------+------------------+--------+-------------------+---------------+----------+-------------+--------------------+------------------------------+----------
+ regress_testsub | regress_subscription_user | f | {testpub2,testpub3} | f | off | d | f | any | t | f | f | f | off | dbname=regress_doesnotexist2 | 0/0
(1 row)
BEGIN;
@@ -223,10 +223,10 @@ ALTER SUBSCRIPTION regress_testsub_foo SET (synchronous_commit = foobar);
ERROR: invalid value for parameter "synchronous_commit": "foobar"
HINT: Available values: local, remote_write, remote_apply, on, off.
\dRs+
- List of subscriptions
- Name | Owner | Enabled | Publication | Binary | Streaming | Two-phase commit | Disable on error | Origin | Password required | Run as owner? | Failover | Synchronous commit | Conninfo | Skip LSN
----------------------+---------------------------+---------+---------------------+--------+-----------+------------------+------------------+--------+-------------------+---------------+----------+--------------------+------------------------------+----------
- regress_testsub_foo | regress_subscription_user | f | {testpub2,testpub3} | f | off | d | f | any | t | f | f | local | dbname=regress_doesnotexist2 | 0/0
+ List of subscriptions
+ Name | Owner | Enabled | Publication | Binary | Streaming | Two-phase commit | Disable on error | Origin | Password required | Run as owner? | Failover | Force_alter | Synchronous commit | Conninfo | Skip LSN
+---------------------+---------------------------+---------+---------------------+--------+-----------+------------------+------------------+--------+-------------------+---------------+----------+-------------+--------------------+------------------------------+----------
+ regress_testsub_foo | regress_subscription_user | f | {testpub2,testpub3} | f | off | d | f | any | t | f | f | f | local | dbname=regress_doesnotexist2 | 0/0
(1 row)
-- rename back to keep the rest simple
@@ -255,19 +255,19 @@ CREATE SUBSCRIPTION regress_testsub CONNECTION 'dbname=regress_doesnotexist' PUB
WARNING: subscription was created, but is not connected
HINT: To initiate replication, you must manually create the replication slot, enable the subscription, and refresh the subscription.
\dRs+
- List of subscriptions
- Name | Owner | Enabled | Publication | Binary | Streaming | Two-phase commit | Disable on error | Origin | Password required | Run as owner? | Failover | Synchronous commit | Conninfo | Skip LSN
------------------+---------------------------+---------+-------------+--------+-----------+------------------+------------------+--------+-------------------+---------------+----------+--------------------+-----------------------------+----------
- regress_testsub | regress_subscription_user | f | {testpub} | t | off | d | f | any | t | f | f | off | dbname=regress_doesnotexist | 0/0
+ List of subscriptions
+ Name | Owner | Enabled | Publication | Binary | Streaming | Two-phase commit | Disable on error | Origin | Password required | Run as owner? | Failover | Force_alter | Synchronous commit | Conninfo | Skip LSN
+-----------------+---------------------------+---------+-------------+--------+-----------+------------------+------------------+--------+-------------------+---------------+----------+-------------+--------------------+-----------------------------+----------
+ regress_testsub | regress_subscription_user | f | {testpub} | t | off | d | f | any | t | f | f | f | off | dbname=regress_doesnotexist | 0/0
(1 row)
ALTER SUBSCRIPTION regress_testsub SET (binary = false);
ALTER SUBSCRIPTION regress_testsub SET (slot_name = NONE);
\dRs+
- List of subscriptions
- Name | Owner | Enabled | Publication | Binary | Streaming | Two-phase commit | Disable on error | Origin | Password required | Run as owner? | Failover | Synchronous commit | Conninfo | Skip LSN
------------------+---------------------------+---------+-------------+--------+-----------+------------------+------------------+--------+-------------------+---------------+----------+--------------------+-----------------------------+----------
- regress_testsub | regress_subscription_user | f | {testpub} | f | off | d | f | any | t | f | f | off | dbname=regress_doesnotexist | 0/0
+ List of subscriptions
+ Name | Owner | Enabled | Publication | Binary | Streaming | Two-phase commit | Disable on error | Origin | Password required | Run as owner? | Failover | Force_alter | Synchronous commit | Conninfo | Skip LSN
+-----------------+---------------------------+---------+-------------+--------+-----------+------------------+------------------+--------+-------------------+---------------+----------+-------------+--------------------+-----------------------------+----------
+ regress_testsub | regress_subscription_user | f | {testpub} | f | off | d | f | any | t | f | f | f | off | dbname=regress_doesnotexist | 0/0
(1 row)
DROP SUBSCRIPTION regress_testsub;
@@ -279,27 +279,27 @@ CREATE SUBSCRIPTION regress_testsub CONNECTION 'dbname=regress_doesnotexist' PUB
WARNING: subscription was created, but is not connected
HINT: To initiate replication, you must manually create the replication slot, enable the subscription, and refresh the subscription.
\dRs+
- List of subscriptions
- Name | Owner | Enabled | Publication | Binary | Streaming | Two-phase commit | Disable on error | Origin | Password required | Run as owner? | Failover | Synchronous commit | Conninfo | Skip LSN
------------------+---------------------------+---------+-------------+--------+-----------+------------------+------------------+--------+-------------------+---------------+----------+--------------------+-----------------------------+----------
- regress_testsub | regress_subscription_user | f | {testpub} | f | on | d | f | any | t | f | f | off | dbname=regress_doesnotexist | 0/0
+ List of subscriptions
+ Name | Owner | Enabled | Publication | Binary | Streaming | Two-phase commit | Disable on error | Origin | Password required | Run as owner? | Failover | Force_alter | Synchronous commit | Conninfo | Skip LSN
+-----------------+---------------------------+---------+-------------+--------+-----------+------------------+------------------+--------+-------------------+---------------+----------+-------------+--------------------+-----------------------------+----------
+ regress_testsub | regress_subscription_user | f | {testpub} | f | on | d | f | any | t | f | f | f | off | dbname=regress_doesnotexist | 0/0
(1 row)
ALTER SUBSCRIPTION regress_testsub SET (streaming = parallel);
\dRs+
- List of subscriptions
- Name | Owner | Enabled | Publication | Binary | Streaming | Two-phase commit | Disable on error | Origin | Password required | Run as owner? | Failover | Synchronous commit | Conninfo | Skip LSN
------------------+---------------------------+---------+-------------+--------+-----------+------------------+------------------+--------+-------------------+---------------+----------+--------------------+-----------------------------+----------
- regress_testsub | regress_subscription_user | f | {testpub} | f | parallel | d | f | any | t | f | f | off | dbname=regress_doesnotexist | 0/0
+ List of subscriptions
+ Name | Owner | Enabled | Publication | Binary | Streaming | Two-phase commit | Disable on error | Origin | Password required | Run as owner? | Failover | Force_alter | Synchronous commit | Conninfo | Skip LSN
+-----------------+---------------------------+---------+-------------+--------+-----------+------------------+------------------+--------+-------------------+---------------+----------+-------------+--------------------+-----------------------------+----------
+ regress_testsub | regress_subscription_user | f | {testpub} | f | parallel | d | f | any | t | f | f | f | off | dbname=regress_doesnotexist | 0/0
(1 row)
ALTER SUBSCRIPTION regress_testsub SET (streaming = false);
ALTER SUBSCRIPTION regress_testsub SET (slot_name = NONE);
\dRs+
- List of subscriptions
- Name | Owner | Enabled | Publication | Binary | Streaming | Two-phase commit | Disable on error | Origin | Password required | Run as owner? | Failover | Synchronous commit | Conninfo | Skip LSN
------------------+---------------------------+---------+-------------+--------+-----------+------------------+------------------+--------+-------------------+---------------+----------+--------------------+-----------------------------+----------
- regress_testsub | regress_subscription_user | f | {testpub} | f | off | d | f | any | t | f | f | off | dbname=regress_doesnotexist | 0/0
+ List of subscriptions
+ Name | Owner | Enabled | Publication | Binary | Streaming | Two-phase commit | Disable on error | Origin | Password required | Run as owner? | Failover | Force_alter | Synchronous commit | Conninfo | Skip LSN
+-----------------+---------------------------+---------+-------------+--------+-----------+------------------+------------------+--------+-------------------+---------------+----------+-------------+--------------------+-----------------------------+----------
+ regress_testsub | regress_subscription_user | f | {testpub} | f | off | d | f | any | t | f | f | f | off | dbname=regress_doesnotexist | 0/0
(1 row)
-- fail - publication already exists
@@ -314,10 +314,10 @@ ALTER SUBSCRIPTION regress_testsub ADD PUBLICATION testpub1, testpub2 WITH (refr
ALTER SUBSCRIPTION regress_testsub ADD PUBLICATION testpub1, testpub2 WITH (refresh = false);
ERROR: publication "testpub1" is already in subscription "regress_testsub"
\dRs+
- List of subscriptions
- Name | Owner | Enabled | Publication | Binary | Streaming | Two-phase commit | Disable on error | Origin | Password required | Run as owner? | Failover | Synchronous commit | Conninfo | Skip LSN
------------------+---------------------------+---------+-----------------------------+--------+-----------+------------------+------------------+--------+-------------------+---------------+----------+--------------------+-----------------------------+----------
- regress_testsub | regress_subscription_user | f | {testpub,testpub1,testpub2} | f | off | d | f | any | t | f | f | off | dbname=regress_doesnotexist | 0/0
+ List of subscriptions
+ Name | Owner | Enabled | Publication | Binary | Streaming | Two-phase commit | Disable on error | Origin | Password required | Run as owner? | Failover | Force_alter | Synchronous commit | Conninfo | Skip LSN
+-----------------+---------------------------+---------+-----------------------------+--------+-----------+------------------+------------------+--------+-------------------+---------------+----------+-------------+--------------------+-----------------------------+----------
+ regress_testsub | regress_subscription_user | f | {testpub,testpub1,testpub2} | f | off | d | f | any | t | f | f | f | off | dbname=regress_doesnotexist | 0/0
(1 row)
-- fail - publication used more than once
@@ -332,10 +332,10 @@ ERROR: publication "testpub3" is not in subscription "regress_testsub"
-- ok - delete publications
ALTER SUBSCRIPTION regress_testsub DROP PUBLICATION testpub1, testpub2 WITH (refresh = false);
\dRs+
- List of subscriptions
- Name | Owner | Enabled | Publication | Binary | Streaming | Two-phase commit | Disable on error | Origin | Password required | Run as owner? | Failover | Synchronous commit | Conninfo | Skip LSN
------------------+---------------------------+---------+-------------+--------+-----------+------------------+------------------+--------+-------------------+---------------+----------+--------------------+-----------------------------+----------
- regress_testsub | regress_subscription_user | f | {testpub} | f | off | d | f | any | t | f | f | off | dbname=regress_doesnotexist | 0/0
+ List of subscriptions
+ Name | Owner | Enabled | Publication | Binary | Streaming | Two-phase commit | Disable on error | Origin | Password required | Run as owner? | Failover | Force_alter | Synchronous commit | Conninfo | Skip LSN
+-----------------+---------------------------+---------+-------------+--------+-----------+------------------+------------------+--------+-------------------+---------------+----------+-------------+--------------------+-----------------------------+----------
+ regress_testsub | regress_subscription_user | f | {testpub} | f | off | d | f | any | t | f | f | f | off | dbname=regress_doesnotexist | 0/0
(1 row)
DROP SUBSCRIPTION regress_testsub;
@@ -371,19 +371,19 @@ CREATE SUBSCRIPTION regress_testsub CONNECTION 'dbname=regress_doesnotexist' PUB
WARNING: subscription was created, but is not connected
HINT: To initiate replication, you must manually create the replication slot, enable the subscription, and refresh the subscription.
\dRs+
- List of subscriptions
- Name | Owner | Enabled | Publication | Binary | Streaming | Two-phase commit | Disable on error | Origin | Password required | Run as owner? | Failover | Synchronous commit | Conninfo | Skip LSN
------------------+---------------------------+---------+-------------+--------+-----------+------------------+------------------+--------+-------------------+---------------+----------+--------------------+-----------------------------+----------
- regress_testsub | regress_subscription_user | f | {testpub} | f | off | p | f | any | t | f | f | off | dbname=regress_doesnotexist | 0/0
+ List of subscriptions
+ Name | Owner | Enabled | Publication | Binary | Streaming | Two-phase commit | Disable on error | Origin | Password required | Run as owner? | Failover | Force_alter | Synchronous commit | Conninfo | Skip LSN
+-----------------+---------------------------+---------+-------------+--------+-----------+------------------+------------------+--------+-------------------+---------------+----------+-------------+--------------------+-----------------------------+----------
+ regress_testsub | regress_subscription_user | f | {testpub} | f | off | p | f | any | t | f | f | f | off | dbname=regress_doesnotexist | 0/0
(1 row)
-- We can alter streaming when two_phase enabled
ALTER SUBSCRIPTION regress_testsub SET (streaming = true);
\dRs+
- List of subscriptions
- Name | Owner | Enabled | Publication | Binary | Streaming | Two-phase commit | Disable on error | Origin | Password required | Run as owner? | Failover | Synchronous commit | Conninfo | Skip LSN
------------------+---------------------------+---------+-------------+--------+-----------+------------------+------------------+--------+-------------------+---------------+----------+--------------------+-----------------------------+----------
- regress_testsub | regress_subscription_user | f | {testpub} | f | on | p | f | any | t | f | f | off | dbname=regress_doesnotexist | 0/0
+ List of subscriptions
+ Name | Owner | Enabled | Publication | Binary | Streaming | Two-phase commit | Disable on error | Origin | Password required | Run as owner? | Failover | Force_alter | Synchronous commit | Conninfo | Skip LSN
+-----------------+---------------------------+---------+-------------+--------+-----------+------------------+------------------+--------+-------------------+---------------+----------+-------------+--------------------+-----------------------------+----------
+ regress_testsub | regress_subscription_user | f | {testpub} | f | on | p | f | any | t | f | f | f | off | dbname=regress_doesnotexist | 0/0
(1 row)
ALTER SUBSCRIPTION regress_testsub SET (slot_name = NONE);
@@ -393,10 +393,10 @@ CREATE SUBSCRIPTION regress_testsub CONNECTION 'dbname=regress_doesnotexist' PUB
WARNING: subscription was created, but is not connected
HINT: To initiate replication, you must manually create the replication slot, enable the subscription, and refresh the subscription.
\dRs+
- List of subscriptions
- Name | Owner | Enabled | Publication | Binary | Streaming | Two-phase commit | Disable on error | Origin | Password required | Run as owner? | Failover | Synchronous commit | Conninfo | Skip LSN
------------------+---------------------------+---------+-------------+--------+-----------+------------------+------------------+--------+-------------------+---------------+----------+--------------------+-----------------------------+----------
- regress_testsub | regress_subscription_user | f | {testpub} | f | on | p | f | any | t | f | f | off | dbname=regress_doesnotexist | 0/0
+ List of subscriptions
+ Name | Owner | Enabled | Publication | Binary | Streaming | Two-phase commit | Disable on error | Origin | Password required | Run as owner? | Failover | Force_alter | Synchronous commit | Conninfo | Skip LSN
+-----------------+---------------------------+---------+-------------+--------+-----------+------------------+------------------+--------+-------------------+---------------+----------+-------------+--------------------+-----------------------------+----------
+ regress_testsub | regress_subscription_user | f | {testpub} | f | on | p | f | any | t | f | f | f | off | dbname=regress_doesnotexist | 0/0
(1 row)
ALTER SUBSCRIPTION regress_testsub SET (slot_name = NONE);
@@ -409,18 +409,18 @@ CREATE SUBSCRIPTION regress_testsub CONNECTION 'dbname=regress_doesnotexist' PUB
WARNING: subscription was created, but is not connected
HINT: To initiate replication, you must manually create the replication slot, enable the subscription, and refresh the subscription.
\dRs+
- List of subscriptions
- Name | Owner | Enabled | Publication | Binary | Streaming | Two-phase commit | Disable on error | Origin | Password required | Run as owner? | Failover | Synchronous commit | Conninfo | Skip LSN
------------------+---------------------------+---------+-------------+--------+-----------+------------------+------------------+--------+-------------------+---------------+----------+--------------------+-----------------------------+----------
- regress_testsub | regress_subscription_user | f | {testpub} | f | off | d | f | any | t | f | f | off | dbname=regress_doesnotexist | 0/0
+ List of subscriptions
+ Name | Owner | Enabled | Publication | Binary | Streaming | Two-phase commit | Disable on error | Origin | Password required | Run as owner? | Failover | Force_alter | Synchronous commit | Conninfo | Skip LSN
+-----------------+---------------------------+---------+-------------+--------+-----------+------------------+------------------+--------+-------------------+---------------+----------+-------------+--------------------+-----------------------------+----------
+ regress_testsub | regress_subscription_user | f | {testpub} | f | off | d | f | any | t | f | f | f | off | dbname=regress_doesnotexist | 0/0
(1 row)
ALTER SUBSCRIPTION regress_testsub SET (disable_on_error = true);
\dRs+
- List of subscriptions
- Name | Owner | Enabled | Publication | Binary | Streaming | Two-phase commit | Disable on error | Origin | Password required | Run as owner? | Failover | Synchronous commit | Conninfo | Skip LSN
------------------+---------------------------+---------+-------------+--------+-----------+------------------+------------------+--------+-------------------+---------------+----------+--------------------+-----------------------------+----------
- regress_testsub | regress_subscription_user | f | {testpub} | f | off | d | t | any | t | f | f | off | dbname=regress_doesnotexist | 0/0
+ List of subscriptions
+ Name | Owner | Enabled | Publication | Binary | Streaming | Two-phase commit | Disable on error | Origin | Password required | Run as owner? | Failover | Force_alter | Synchronous commit | Conninfo | Skip LSN
+-----------------+---------------------------+---------+-------------+--------+-----------+------------------+------------------+--------+-------------------+---------------+----------+-------------+--------------------+-----------------------------+----------
+ regress_testsub | regress_subscription_user | f | {testpub} | f | off | d | t | any | t | f | f | f | off | dbname=regress_doesnotexist | 0/0
(1 row)
ALTER SUBSCRIPTION regress_testsub SET (slot_name = NONE);
diff --git a/src/test/subscription/t/099_twophase_added.pl b/src/test/subscription/t/099_twophase_added.pl
index 9cc1ca9167..22b4f2d9a0 100644
--- a/src/test/subscription/t/099_twophase_added.pl
+++ b/src/test/subscription/t/099_twophase_added.pl
@@ -97,7 +97,8 @@ is($result, q(5),
# Check the case that prepared transactions exist on the subscriber node
#
# If the two_phase is altering from "on" to "off" and there are prepared
-# transactions on the subscriber, they must be aborted. This test checks it.
+# transactions on the subscriber, we must error out or abort all prepared
+# transactions. Below part checks both cases.
# Prepare a transaction to insert some tuples into the table
$node_publisher->safe_psql(
@@ -114,15 +115,39 @@ $result = $node_subscriber->safe_psql('postgres',
"SELECT count(*) FROM pg_prepared_xacts;");
is($result, q(1), "transaction has been prepared on subscriber");
-# Toggle the two_phase to "off" before the COMMIT PREPARED
-$node_subscriber->safe_psql(
- 'postgres', "
- ALTER SUBSCRIPTION regress_sub DISABLE;
- ALTER SUBSCRIPTION regress_sub SET (two_phase = off);
- ALTER SUBSCRIPTION regress_sub ENABLE;");
+# Disable the subscription to alter the two_phase option
+$node_subscriber->safe_psql('postgres', "ALTER SUBSCRIPTION regress_sub DISABLE;");
+
+# Try altering the two_phase option to "off." The command will fail since there
+# is a prepared transaction and the 'force_alter' option is not specified as
+# true.
+my $stdout;
+my $stderr;
+
+($result, $stdout, $stderr) = $node_subscriber->psql(
+ 'postgres', "ALTER SUBSCRIPTION regress_sub SET (two_phase = off);");
+ok($stderr =~ /cannot alter two_phase = off when there are prepared transactions/,
+ 'ALTER SUBSCRIPTION failed');
+
+# Verify the prepared transaction still exists
+$result = $node_subscriber->safe_psql('postgres',
+ "SELECT count(*) FROM pg_prepared_xacts;");
+is($result, q(1), "prepared transaction still exists");
+
+$log_offset = -s $node_subscriber->logfile;
+
+# Alter the two_phase with the force_alter option. Apart from the the last
+# ALTER SUBSCRIPTION command, the command will abort the prepared transaction
+# and succeed.
+$node_subscriber->safe_psql('postgres',
+ "ALTER SUBSCRIPTION regress_sub SET (two_phase = off, force_alter = true);");
+$node_subscriber->safe_psql('postgres', "ALTER SUBSCRIPTION regress_sub ENABLE;");
+
+# Verify the started worker recognized two_phase was disabled
+$node_subscriber->wait_for_log(
+ 'logical replication apply worker for subscription "regress_sub" two_phase is DISABLED', $log_offset);
-# Verify any prepared transactions are aborted because two_phase is changed to
-# "off".
+# Verify the prepared transaction was aborted
$result = $node_subscriber->safe_psql('postgres',
"SELECT count(*) FROM pg_prepared_xacts;");
is($result, q(0), "prepared transaction done by worker is aborted");
--
2.43.0
^ permalink raw reply [nested|flat] 25+ messages in thread
* RE: Slow catchup of 2PC (twophase) transactions on replica in LR
@ 2024-05-13 12:27 Hayato Kuroda (Fujitsu) <[email protected]>
parent: Peter Smith <[email protected]>
0 siblings, 0 replies; 25+ messages in thread
From: Hayato Kuroda (Fujitsu) @ 2024-05-13 12:27 UTC (permalink / raw)
To: 'Peter Smith' <[email protected]>; +Cc: [email protected] <[email protected]>; Amit Kapila <[email protected]>; Ajin Cherian <[email protected]>; Давыдов Виталий <[email protected]>
Dear Peter,
Thanks for reviewing! Patch can be available in [1].
> ======
> src/sgml/ref/alter_subscription.sgml
>
> 1.
> + <para>
> + The <literal>two_phase</literal> parameter can only be altered when
> the
> + subscription is disabled. When altering the parameter from
> <literal>on</literal>
> + to <literal>off</literal>, the backend process checks prepared
> + transactions done by the logical replication worker and aborts them.
> + </para>
>
> The text may be OK as-is, but I was wondering if it might be better to
> give a more verbose explanation.
>
> BEFORE
> ... the backend process checks prepared transactions done by the
> logical replication worker and aborts them.
>
> SUGGESTION
> ... the backend process checks for any incomplete prepared
> transactions done by the logical replication worker (from when
> two_phase parameter was still "on") and, if any are found, those are
> aborted.
>
Fixed.
> ======
> src/backend/commands/subscriptioncmds.c
>
> 2. AlterSubscription
>
> - /*
> - * Since the altering two_phase option of subscriptions
> - * also leads to the change of slot option, this command
> - * cannot be rolled back. So prevent we are in the
> - * transaction block.
> + * If two_phase was enabled, there is a possibility the
> + * transactions has already been PREPARE'd. They must be
> + * checked and rolled back.
> */
>
> BEFORE
> ... there is a possibility the transactions has already been PREPARE'd.
>
> SUGGESTION
> ... there is a possibility that transactions have already been PREPARE'd.
Fixed.
> 3. AlterSubscription
> + /*
> + * Since the altering two_phase option of subscriptions
> + * (especially on->off case) also leads to the
> + * change of slot option, this command cannot be rolled
> + * back. So prevent we are in the transaction block.
> + */
> PreventInTransactionBlock(isTopLevel,
> "ALTER SUBSCRIPTION ... SET (two_phase = off)");
>
>
> This comment is a bit vague and includes some typos, but IIUC these
> problems will already be addressed by the 0002 patch changes.AFAIK
> patch 0003 is only moving the 0002 comment.
Yeah, the comment was updated accordingly.
>
> ======
> src/test/subscription/t/099_twophase_added.pl
>
> 4.
> +# Check the case that prepared transactions exist on the subscriber node
> +#
> +# If the two_phase is altering from "on" to "off" and there are prepared
> +# transactions on the subscriber, they must be aborted. This test checks it.
> +
>
> Similar to the comment that I gave for v8-0002. I think there should
> be #################### comment for the major test comment to
> distinguish it from comments for the sub-steps.
Added.
> 5.
> +# Verify the prepared transaction are aborted because two_phase is changed to
> +# "off".
> +$result = $node_subscriber->safe_psql('postgres',
> + "SELECT count(*) FROM pg_prepared_xacts;");
> +is($result, q(0), "prepared transaction done by worker is aborted");
> +
>
> /the prepared transaction are aborted/any prepared transactions are aborted/
Fixed.
[1]: https://www.postgresql.org/message-id/OSBPR01MB2552FEA48D265EA278AA9F7AF5E22%40OSBPR01MB2552.jpnprd0...
Best Regards,
Hayato Kuroda
FUJITSU LIMITED
https://www.fujitsu.com/
^ permalink raw reply [nested|flat] 25+ messages in thread
* RE: Slow catchup of 2PC (twophase) transactions on replica in LR
@ 2024-05-13 12:28 Hayato Kuroda (Fujitsu) <[email protected]>
parent: Peter Smith <[email protected]>
0 siblings, 0 replies; 25+ messages in thread
From: Hayato Kuroda (Fujitsu) @ 2024-05-13 12:28 UTC (permalink / raw)
To: 'Peter Smith' <[email protected]>; +Cc: [email protected] <[email protected]>; Amit Kapila <[email protected]>; Ajin Cherian <[email protected]>; Давыдов Виталий <[email protected]>
Dear Peter,
Thanks for giving comments! New patch was posted in [1].
> 0.1 General - Patch name
>
> /SUBSCIRPTION/SUBSCRIPTION/
Fixed.
> ======
> 0.2 General - Apply
>
> FYI, there are whitespace warnings:
>
> git
> apply ../patches_misc/v8-0004-Add-force_alter-option-for-ALTER-SUBSCIRPTI
> ON-.-S.patch
> ../patches_misc/v8-0004-Add-force_alter-option-for-ALTER-SUBSCIRPTION-.-
> S.patch:191:
> trailing whitespace.
> # command will abort the prepared transaction and succeed.
> warning: 1 line adds whitespace errors.
I didn't recognize, fixed.
> ======
> 0.3 General - Regression test fails
>
> The subscription regression tests are not working.
>
> ok 158 + publication 1187 ms
> not ok 159 + subscription 123 ms
>
> See review comments #4 and #5 below for the reason why.
Yeah, I missed to update the expected result. Fixed.
> ======
> src/sgml/ref/alter_subscription.sgml
>
> 1.
> <para>
> The <literal>two_phase</literal> parameter can only be altered when
> the
> - subscription is disabled. When altering the parameter from
> <literal>on</literal>
> - to <literal>off</literal>, the backend process checks prepared
> - transactions done by the logical replication worker and aborts them.
> + subscription is disabled. Altering the parameter from
> <literal>on</literal>
> + to <literal>off</literal> will be failed when there are prepared
> + transactions done by the logical replication worker. If you want to alter
> + the parameter forcibly in this case, <literal>force_alter</literal>
> + option must be set to <literal>on</literal> at the same time. If
> + specified, the backend process aborts prepared transactions.
> </para>
> 1a.
> That "will be failed when..." seems strange. Maybe say "will give an
> error when..."
>
> ~
> 1b.
> Because "force" is a verb, I think true/false is more natural than
> on/off for this new boolean option. e.g. it acts more like a "flag"
> than a "mode". See all the other boolean options in CREATE
> SUBSCRIPTION -- those are mostly all verbs too and are all true/false
> AFAIK.
Fixed, but note that the part was moved.
>
> ======
>
> 2. CREATE SUBSCRIPTION
>
> For my previous review, two comments [v7-0004#2] and [v7-0004#3] were
> not addressed. Kuroda-san wrote:
> Hmm, but the parameter cannot be used for CREATE SUBSCRIPTION. Should
> we modify to accept and add the description in the doc?
>
> ~
>
> Yes, that is what I am suggesting. IMO it is odd for the user to be
> able to ALTER a parameter that cannot be included in the CREATE
> SUBSCRIPTION in the first place. AFAIK there are no other parameters
> that behave that way.
Hmm. I felt that this change required the new attribute in pg_subscription system
catalog. Previously I did not like because it contains huge change, but...I tried to do.
New attribute 'subforcealter', and some parts were updated accordingly.
> src/backend/commands/subscriptioncmds.c
>
> 3. AlterSubscription
>
> + if (!opts.force_alter)
> + ereport(ERROR,
> + (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
> + errmsg("cannot alter %s when there are prepared transactions",
> + "two_phase = off"),
> + errhint("Resolve these transactions or set %s at the same time, and
> then try again.",
> + "force_alter = true")));
>
> I think saying "at the same time" in the hint is unnecessary. Surely
> the user is allowed to set this parameter separately if they want to?
>
> e.g.
> ALTER SUBSCRIPTION sub SET (force_alter=true);
> ALTER SUBSCRIPTION sub SET (two_phase=off);
Actually, it was correct. Since force_alter was not recorded in the system catalog, it must
be specified at the same time.
Now, we allow to be separated, so removed.
> ======
> src/test/regress/expected/subscription.out
>
> 4.
> +-- fail - force_alter cannot be set alone
> +ALTER SUBSCRIPTION regress_testsub SET (force_alter = true);
> +ERROR: force_alter must be specified with two_phase
>
> This error cannot happen. You removed that error!
Fixed.
> ======
> src/test/subscription/t/099_twophase_added.pl
>
> 6.
> +# Try altering the two_phase option to "off." The command will fail since there
> +# is a prepared transaction and the force option is not specified.
> +my $stdout;
> +my $stderr;
> +
> +($result, $stdout, $stderr) = $node_subscriber->psql(
> + 'postgres', "ALTER SUBSCRIPTION regress_sub SET (two_phase = off);");
> +ok($stderr =~ /cannot alter two_phase = off when there are prepared
> transactions/,
> + 'ALTER SUBSCRIPTION failed');
>
> /force option is not specified./'force_alter' option is not specified as true./
Fixed.
>
> 7.
> +# Verify the prepared transaction still exists
> +$result = $node_subscriber->safe_psql('postgres',
> + "SELECT count(*) FROM pg_prepared_xacts;");
> +is($result, q(1), "prepared transaction still exits");
> +
>
> TYPO: /exits/exists/
Fixed.
>
> ~~~
>
> 8.
> +# Alter the two_phase with the force_alter option. Apart from the above, the
> +# command will abort the prepared transaction and succeed.
> +$node_subscriber->safe_psql('postgres',
> + "ALTER SUBSCRIPTION regress_sub SET (two_phase = off, force_alter
> = true);");
> +$node_subscriber->safe_psql('postgres', "ALTER SUBSCRIPTION
> regress_sub ENABLE;");
> +
>
> What does "Apart from the above" mean? Be more explicit.
Clarified like "Apart from the last ALTER SUBSCRIPTION command...".
> 9.
> +# Verify the prepared transaction are aborted
> $result = $node_subscriber->safe_psql('postgres',
> "SELECT count(*) FROM pg_prepared_xacts;");
> is($result, q(0), "prepared transaction done by worker is aborted");
>
> /transaction are aborted/transaction was aborted/
Fixed.
[1]: https://www.postgresql.org/message-id/OSBPR01MB2552FEA48D265EA278AA9F7AF5E22%40OSBPR01MB2552.jpnprd0...
Best Regards,
Hayato Kuroda
FUJITSU LIMITED
https://www.fujitsu.com/
^ permalink raw reply [nested|flat] 25+ messages in thread
* Re: Slow catchup of 2PC (twophase) transactions on replica in LR
@ 2024-05-14 04:06 Peter Smith <[email protected]>
parent: Hayato Kuroda (Fujitsu) <[email protected]>
1 sibling, 0 replies; 25+ messages in thread
From: Peter Smith @ 2024-05-14 04:06 UTC (permalink / raw)
To: Hayato Kuroda (Fujitsu) <[email protected]>; +Cc: [email protected] <[email protected]>; Amit Kapila <[email protected]>; Ajin Cherian <[email protected]>; Давыдов Виталий <[email protected]>
Hi Kuroda-san,
I'm having second thoughts about how these patches mention the option
values "on|off". These are used in the ALTER SUBSCRIPTION document
page for 'two_phase' and 'failover' parameters, and then those
"on|off" get propagated to the code comments, error messages, and
tests...
Now I see that on the CREATE SUBSCRIPTION page [1], every boolean
parameter (even including 'two_phase' and 'failover') is described in
terms of "true|false" (not "on|off").
In hindsight, it is probably better to refer only to true|false
everywhere for these boolean parameters, instead of sometimes using
different values like on|off.
What do you think?
======
[1] https://www.postgresql.org/docs/devel/sql-createsubscription.html
Kind Regards,
Peter Smith.
Fujitsu Australia
^ permalink raw reply [nested|flat] 25+ messages in thread
* Re: Slow catchup of 2PC (twophase) transactions on replica in LR
@ 2024-05-14 04:18 Peter Smith <[email protected]>
parent: Hayato Kuroda (Fujitsu) <[email protected]>
1 sibling, 1 reply; 25+ messages in thread
From: Peter Smith @ 2024-05-14 04:18 UTC (permalink / raw)
To: Hayato Kuroda (Fujitsu) <[email protected]>; +Cc: [email protected] <[email protected]>; Amit Kapila <[email protected]>; Ajin Cherian <[email protected]>; Давыдов Виталий <[email protected]>
Hi Kuroda-san, Here are some review comments for all patches v9*
//////////
Patch v9-0001
//////////
There were no changes since v8-0001, so no comments.
//////////
Patch v9-0002
//////////
======
Commit Message
2.1.
Regarding the off->on case, the logical replication already has a
mechanism for it, so there is no need to do anything special for the
on->off case; however, we must connect to the publisher and expressly
change the parameter. The operation cannot be rolled back, and
altering the parameter from "on" to "off" within a transaction is
prohibited.
In the opposite case, there is no need to prevent this because the
logical replication worker already had the mechanism to alter the slot
option at a convenient time.
~
This explanation seems to be going around in circles, without giving
any new information:
AFAICT, "Regarding the off->on case, the logical replication already
has a mechanism for it, so there is no need to do anything special for
the on->off case;"
is saying pretty much the same as:
"In the opposite case, there is no need to prevent this because the
logical replication worker already had the mechanism to alter the slot
option at a convenient time."
But, what I hoped for in previous review comments was an explanation
somewhat less vague than "already has a mechanism" or "already had the
mechanism". Can't this have just 1 or 2 lines to say WHAT is that
existing mechanism for the "off" to "on" case, and WHY that means
there is nothing special to do in that scenario?
======
src/backend/commands/subscriptioncmds.c
2.2. AlterSubscription
/*
- * The changed two_phase option of the slot can't be rolled
- * back.
+ * Since altering the two_phase option of subscriptions
+ * also leads to changing the slot option, this command
+ * cannot be rolled back. So prevent this if we are in a
+ * transaction block. In the opposite case, there is no
+ * need to prevent this because the logical replication
+ * worker already had the mechanism to alter the slot
+ * option at a convenient time.
*/
(Same previous review comments, and same as my review comment for the
commit message above).
I don't think "already had the mechanism" is enough explanation.
Also, the 2nd sentence doesn't make sense here because the comment
only said "altering the slot option" -- it didn't say it was altering
it to "on" or altering it to "off", so "the opposite case" has no
meaning.
~~~
2.3. AlterSubscription
/*
- * Try to acquire the connection necessary for altering slot.
+ * Check the need to alter the replication slot. Failover and two_phase
+ * options are controlled by both the publisher (as a slot option) and the
+ * subscriber (as a subscription option). The slot option must be altered
+ * only when changing "on" to "off". Because in opposite case, the logical
+ * replication worker already has the mechanism to do so at a convenient
+ * time.
+ */
+ update_failover = replaces[Anum_pg_subscription_subfailover - 1];
+ update_two_phase = (replaces[Anum_pg_subscription_subtwophasestate - 1] &&
+ !opts.twophase);
This is again the same as other review comments above. Probably, when
some better explanation can be found for "already has the mechanism to
do so at a convenient time." then all of these places can be changed
using similar text.
//////////
Patch v9-0003
//////////
There are some imperfect code comments but AFAIK they are the same
ones from patch 0002. I think patch 0003 is just moving those comments
to different places, so probably they would already be addressed by
patch 0002.
//////////
Patch v9-0004
//////////
======
doc/src/sgml/catalogs.sgml
4.1.
+ <row>
+ <entry role="catalog_table_entry"><para role="column_definition">
+ <structfield>subforcealter</structfield> <type>bool</type>
+ </para>
+ <para>
+ If true, the subscription can be altered <literal>two_phase</literal>
+ option, even if there are prepared transactions
+ </para></entry>
+ </row>
+
BEFORE
If true, the subscription can be altered <literal>two_phase</literal>
option, even if there are prepared transactions
SUGGESTION
If true, then the ALTER SUBSCRIPTION command can disable
<literal>two_phase</literal> option, even if there are uncommitted
prepared transactions from when <literal>two_phase</literal> was
enabled
======
doc/src/sgml/ref/alter_subscription.sgml
4.2.
-
- <para>
- The <literal>two_phase</literal> parameter can only be altered when the
- subscription is disabled. When altering the parameter from
<literal>on</literal>
- to <literal>off</literal>, the backend process checks for any incomplete
- prepared transactions done by the logical replication worker (from when
- <literal>two_phase</literal> parameter was still <literal>on</literal>)
- and, if any are found, those are aborted.
- </para>
Well, I still think there ought to be some mention of the relationship
between 'force_alter' and 'two_phase' given on this ALTER SUBSCRIPTION
page. Then the user can cross-reference to read what the 'force_alter'
actually does.
======
doc/src/sgml/ref/create_subscription.sgml
4.3.
+
+ <varlistentry id="sql-createsubscription-params-with-force-alter">
+ <term><literal>force_alter</literal> (<type>boolean</type>)</term>
+ <listitem>
+ <para>
+ Specifies whether the subscription can be altered
+ <literal>two_phase</literal> option, even if there are prepared
+ transactions. If specified, the backend process checks for any
+ incomplete prepared transactions done by the logical replication
+ worker (from when <literal>two_phase</literal> parameter was still
+ <literal>on</literal>), if any are found, those are aborted.
+ Otherwise, Altering the parameter from <literal>on</literal> to
+ <literal>off</literal> will give an error when there are prepared
+ transactions done by the logical replication worker.
+ The default is <literal>false</literal>.
+ </para>
+ </listitem>
+ </varlistentry>
This explanation seems a bit repetitive. I think it can be improved as follows:
SUGGESTION
Specifies if the ALTER SUBSCRIPTION can be forced to proceed instead
of giving an error.
There is currently only one scenario where this parameter has any
effect: When altering two_phase option from true to false it is
possible for there to be incomplete prepared transactions done by the
logical replication worker (from when two_phase parameter was still
true). If force_alter is false, then this will give an error; if
force_alter is true, then the incomplete prepared transactions are
aborted and the alter will proceed.
The default is false.
======
src/backend/commands/subscriptioncmds.c
4.4. CreateSubscription
values[Anum_pg_subscription_subfailover - 1] = BoolGetDatum(opts.failover);
+ values[Anum_pg_subscription_subforcealter] = BoolGetDatum(opts.force_alter);
values[Anum_pg_subscription_subconninfo - 1] =
Hmm, looks like a bug. Shouldn't that index say -1?
~~~
4.5. AlterSubscription
+ /*
+ * Abort prepared transactions only if
+ * 'force_alter' option is true. Otherwise raise
+ * an ERROR.
+ */
+ if (IsSet(opts.specified_opts, SUBOPT_FORCE_ALTER))
+ {
+ if (!opts.force_alter)
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("cannot alter %s when there are prepared transactions",
+ "two_phase = off"),
+ errhint("Resolve these transactions or set %s, and then try again.",
+ "force_alter = true")));
+ }
+ else
+ {
+ if (!sub->forcealter)
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("cannot alter %s when there are prepared transactions",
+ "two_phase = off"),
+ errhint("Resolve these transactions or set %s, and then try again.",
+ "force_alter = true")));
+ }
+
IIUC this code can be simplified to remove the error duplication.
Something like below:
SUGGESTION
bool raise_error = IsSet(opts.specified_opts, SUBOPT_FORCE_ALTER) ?
!opts.force_alter : !sub->forcealter;
if (raise_error)
ereport(ERROR,
(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
errmsg("cannot alter %s when there are prepared transactions",
"two_phase = off"),
errhint("Resolve these transactions or set %s, and then try again.",
"force_alter = true")));
======
src/bin/pg_dump/pg_dump.c
4.6. getSubscriptions
+ if (fout->remoteVersion >= 170000)
+ appendPQExpBufferStr(query,
+ " s.subforcealter\n");
+ else
+ appendPQExpBuffer(query,
+ " false AS subforcealter\n");
+
+
4.6a.
Should this just be combined with the existing "if
(fout->remoteVersion >= 170000)" for failover?
~
4.6b.
Double blank lines.
======
src/bin/psql/describe.c
4.7.
+ if (pset.sversion >= 170000)
+ appendPQExpBuffer(&buf,
+ ", subforcealter AS \"%s\"\n",
+ gettext_noop("Force_alter"));
IMO the column title should be "Force alter" (i.e. without the underscore)
======
src/include/catalog/pg_subscription.h
4.8. CATALOG
+ bool subforcealter; /* True if we allow to drop prepared transactions
+ * when altering two_phase "on"->"off". */
I think this is not actually the description of 'force_alter'. What
you wrote just happens to be the only case that this option currently
works for. Maybe a more correct description is something like below.
SUGGESTION
True allows the ALTER SUBSCRIPTION command to proceed under conditions
that would otherwise result in an error. Currently, 'force_alter' only
has an effect when altering the two_phase option from "true" to
"false".
~~~
4.9. struct Subscription
+ bool forcealter; /* True if we allow to drop prepared
+ * transactions when altering two_phase
+ * "on"->"off". */
Ditto the previous review comment.
======
src/test/regress/expected/subscription.out
4.10.
-
List of subscriptions
- Name | Owner | Enabled | Publication
| Binary | Streaming | Two-phase commit | Disable on error | Origin |
Password required | Run as owner? | Failover | Synchronous commit |
Conninfo | Skip LSN
-------------------+---------------------------+---------+-------------+--------+-----------+------------------+------------------+--------+-------------------+---------------+----------+--------------------+-----------------------------+----------
- regress_testsub4 | regress_subscription_user | f | {testpub}
| f | off | d | f | none |
t | f | f | off |
dbname=regress_doesnotexist | 0/0
+
List of
subscriptions
+ Name | Owner | Enabled | Publication
| Binary | Streaming | Two-phase commit | Disable on error | Origin |
Password required | Run as owner? | Failover | Force_alter |
Synchronous commit | Conninfo | Skip LSN
+------------------+---------------------------+---------+-------------+--------+-----------+------------------+------------------+--------+-------------------+---------------+----------+-------------+--------------------+-----------------------------+----------
The column heading should be "Force alter", as already mentioned by an
earlier review comment (#4.7)
======
src/test/subscription/t/099_twophase_added.pl
4.11.
+# Alter the two_phase with the force_alter option. Apart from the the last
+# ALTER SUBSCRIPTION command, the command will abort the prepared transaction
+# and succeed.
There is typo "the the" and the wording is a bit strange. Why not just say:
SUGGESTION
Alter the two_phase true to false with the force_alter option enabled.
This command will succeed after aborting the prepared transaction.
======
Kind Regards,
Peter Smith.
Fujitsu Australia
^ permalink raw reply [nested|flat] 25+ messages in thread
* RE: Slow catchup of 2PC (twophase) transactions on replica in LR
@ 2024-05-14 12:03 Hayato Kuroda (Fujitsu) <[email protected]>
parent: Peter Smith <[email protected]>
0 siblings, 2 replies; 25+ messages in thread
From: Hayato Kuroda (Fujitsu) @ 2024-05-14 12:03 UTC (permalink / raw)
To: 'Peter Smith' <[email protected]>; +Cc: [email protected] <[email protected]>; Amit Kapila <[email protected]>; Ajin Cherian <[email protected]>; Давыдов Виталий <[email protected]>
Dear Peter,
Thanks for reviewing! Here is new version patch.
> //////////
> Patch v9-0002
> //////////
>
> ======
> Commit Message
>
> 2.1.
> Regarding the off->on case, the logical replication already has a
> mechanism for it, so there is no need to do anything special for the
> on->off case; however, we must connect to the publisher and expressly
> change the parameter. The operation cannot be rolled back, and
> altering the parameter from "on" to "off" within a transaction is
> prohibited.
>
> In the opposite case, there is no need to prevent this because the
> logical replication worker already had the mechanism to alter the slot
> option at a convenient time.
>
> ~
>
> This explanation seems to be going around in circles, without giving
> any new information:
>
> AFAICT, "Regarding the off->on case, the logical replication already
> has a mechanism for it, so there is no need to do anything special for
> the on->off case;"
>
> is saying pretty much the same as:
>
> "In the opposite case, there is no need to prevent this because the
> logical replication worker already had the mechanism to alter the slot
> option at a convenient time."
>
> But, what I hoped for in previous review comments was an explanation
> somewhat less vague than "already has a mechanism" or "already had the
> mechanism". Can't this have just 1 or 2 lines to say WHAT is that
> existing mechanism for the "off" to "on" case, and WHY that means
> there is nothing special to do in that scenario?
>
Reworded. Thought?
> 2.2. AlterSubscription
>
> /*
> - * The changed two_phase option of the slot can't be rolled
> - * back.
> + * Since altering the two_phase option of subscriptions
> + * also leads to changing the slot option, this command
> + * cannot be rolled back. So prevent this if we are in a
> + * transaction block. In the opposite case, there is no
> + * need to prevent this because the logical replication
> + * worker already had the mechanism to alter the slot
> + * option at a convenient time.
> */
>
> (Same previous review comments, and same as my review comment for the
> commit message above).
>
> I don't think "already had the mechanism" is enough explanation.
>
> Also, the 2nd sentence doesn't make sense here because the comment
> only said "altering the slot option" -- it didn't say it was altering
> it to "on" or altering it to "off", so "the opposite case" has no
> meaning.
Fixed.
> 2.3. AlterSubscription
>
> /*
> - * Try to acquire the connection necessary for altering slot.
> + * Check the need to alter the replication slot. Failover and two_phase
> + * options are controlled by both the publisher (as a slot option) and the
> + * subscriber (as a subscription option). The slot option must be altered
> + * only when changing "on" to "off". Because in opposite case, the logical
> + * replication worker already has the mechanism to do so at a convenient
> + * time.
> + */
> + update_failover = replaces[Anum_pg_subscription_subfailover - 1];
> + update_two_phase = (replaces[Anum_pg_subscription_subtwophasestate - 1]
> &&
> + !opts.twophase);
>
> This is again the same as other review comments above. Probably, when
> some better explanation can be found for "already has the mechanism to
> do so at a convenient time." then all of these places can be changed
> using similar text.
Added a reference.
>
> //////////
> Patch v9-0003
> //////////
>
> There are some imperfect code comments but AFAIK they are the same
> ones from patch 0002. I think patch 0003 is just moving those comments
> to different places, so probably they would already be addressed by
> patch 0002.
>
The comment was moved, so no need to modify here.
> ======
> doc/src/sgml/catalogs.sgml
>
> 4.1.
> + <row>
> + <entry role="catalog_table_entry"><para role="column_definition">
> + <structfield>subforcealter</structfield> <type>bool</type>
> + </para>
> + <para>
> + If true, the subscription can be altered <literal>two_phase</literal>
> + option, even if there are prepared transactions
> + </para></entry>
> + </row>
> +
>
> BEFORE
> If true, the subscription can be altered <literal>two_phase</literal>
> option, even if there are prepared transactions
>
> SUGGESTION
> If true, then the ALTER SUBSCRIPTION command can disable
> <literal>two_phase</literal> option, even if there are uncommitted
> prepared transactions from when <literal>two_phase</literal> was
> enabled
Fixed, added a link for ALTER SUBSCRIPTION.
>
> ======
> doc/src/sgml/ref/alter_subscription.sgml
>
> 4.2.
> -
> - <para>
> - The <literal>two_phase</literal> parameter can only be altered when
> the
> - subscription is disabled. When altering the parameter from
> <literal>on</literal>
> - to <literal>off</literal>, the backend process checks for any incomplete
> - prepared transactions done by the logical replication worker (from when
> - <literal>two_phase</literal> parameter was still <literal>on</literal>)
> - and, if any are found, those are aborted.
> - </para>
>
> Well, I still think there ought to be some mention of the relationship
> between 'force_alter' and 'two_phase' given on this ALTER SUBSCRIPTION
> page. Then the user can cross-reference to read what the 'force_alter'
> actually does.
>
Revived the content, and added an link. Thought?
> ======
> doc/src/sgml/ref/create_subscription.sgml
>
> 4.3.
> +
> + <varlistentry id="sql-createsubscription-params-with-force-alter">
> + <term><literal>force_alter</literal>
> (<type>boolean</type>)</term>
> + <listitem>
> + <para>
> + Specifies whether the subscription can be altered
> + <literal>two_phase</literal> option, even if there are prepared
> + transactions. If specified, the backend process checks for any
> + incomplete prepared transactions done by the logical replication
> + worker (from when <literal>two_phase</literal> parameter was
> still
> + <literal>on</literal>), if any are found, those are aborted.
> + Otherwise, Altering the parameter from <literal>on</literal> to
> + <literal>off</literal> will give an error when there are prepared
> + transactions done by the logical replication worker.
> + The default is <literal>false</literal>.
> + </para>
> + </listitem>
> + </varlistentry>
>
> This explanation seems a bit repetitive. I think it can be improved as follows:
>
> SUGGESTION
> Specifies if the ALTER SUBSCRIPTION can be forced to proceed instead
> of giving an error.
>
> There is currently only one scenario where this parameter has any
> effect: When altering two_phase option from true to false it is
> possible for there to be incomplete prepared transactions done by the
> logical replication worker (from when two_phase parameter was still
> true). If force_alter is false, then this will give an error; if
> force_alter is true, then the incomplete prepared transactions are
> aborted and the alter will proceed.
>
> The default is false.
Fixed, but added attributes.
>
> ======
> src/backend/commands/subscriptioncmds.c
>
> 4.4. CreateSubscription
>
> values[Anum_pg_subscription_subfailover - 1] = BoolGetDatum(opts.failover);
> + values[Anum_pg_subscription_subforcealter] =
> BoolGetDatum(opts.force_alter);
> values[Anum_pg_subscription_subconninfo - 1] =
>
> Hmm, looks like a bug. Shouldn't that index say -1?
>
Right, fixed.
> ~~~
> 4.5. AlterSubscription
>
> + /*
> + * Abort prepared transactions only if
> + * 'force_alter' option is true. Otherwise raise
> + * an ERROR.
> + */
> + if (IsSet(opts.specified_opts, SUBOPT_FORCE_ALTER))
> + {
> + if (!opts.force_alter)
> + ereport(ERROR,
> + (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
> + errmsg("cannot alter %s when there are prepared transactions",
> + "two_phase = off"),
> + errhint("Resolve these transactions or set %s, and then try again.",
> + "force_alter = true")));
> + }
> + else
> + {
> + if (!sub->forcealter)
> + ereport(ERROR,
> + (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
> + errmsg("cannot alter %s when there are prepared transactions",
> + "two_phase = off"),
> + errhint("Resolve these transactions or set %s, and then try again.",
> + "force_alter = true")));
> + }
> +
>
> IIUC this code can be simplified to remove the error duplication.
> Something like below:
>
> SUGGESTION
>
> bool raise_error = IsSet(opts.specified_opts, SUBOPT_FORCE_ALTER) ?
> !opts.force_alter : !sub->forcealter;
>
> if (raise_error)
> ereport(ERROR,
> (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
> errmsg("cannot alter %s when there are prepared transactions",
> "two_phase = off"),
> errhint("Resolve these transactions or set %s, and then try again.",
> "force_alter = true")));
>
Modified.
> ======
> src/bin/pg_dump/pg_dump.c
>
> 4.6. getSubscriptions
>
> + if (fout->remoteVersion >= 170000)
> + appendPQExpBufferStr(query,
> + " s.subforcealter\n");
> + else
> + appendPQExpBuffer(query,
> + " false AS subforcealter\n");
> +
> +
>
> 4.6a.
> Should this just be combined with the existing "if
> (fout->remoteVersion >= 170000)" for failover?
This was intentional. Features for PG17 have already been frozen, so
the patch will be pushed for PG18. After removeVersion is bumped,
I want to replace to "(fout->remoteVersion >= 180000)"
>
> ~
>
> 4.6b.
> Double blank lines.
Fixed.
> src/bin/psql/describe.c
>
> 4.7.
> + if (pset.sversion >= 170000)
> + appendPQExpBuffer(&buf,
> + ", subforcealter AS \"%s\"\n",
> + gettext_noop("Force_alter"));
>
> IMO the column title should be "Force alter" (i.e. without the underscore)
>
Fixed.
> ======
> src/include/catalog/pg_subscription.h
>
> 4.8. CATALOG
>
> + bool subforcealter; /* True if we allow to drop prepared transactions
> + * when altering two_phase "on"->"off". */
>
> I think this is not actually the description of 'force_alter'. What
> you wrote just happens to be the only case that this option currently
> works for. Maybe a more correct description is something like below.
>
> SUGGESTION
> True allows the ALTER SUBSCRIPTION command to proceed under conditions
> that would otherwise result in an error. Currently, 'force_alter' only
> has an effect when altering the two_phase option from "true" to
> "false".
>
Hmm. Seems bit long, but used yours.
> ~~~
>
> 4.9. struct Subscription
>
> + bool forcealter; /* True if we allow to drop prepared
> + * transactions when altering two_phase
> + * "on"->"off". */
>
> Ditto the previous review comment.
>
Ditto.
> ======
> src/test/regress/expected/subscription.out
>
> 4.10.
> -
> List of subscriptions
> - Name | Owner | Enabled | Publication
> | Binary | Streaming | Two-phase commit | Disable on error | Origin |
> Password required | Run as owner? | Failover | Synchronous commit |
> Conninfo | Skip LSN
> -------------------+---------------------------+---------+-------------+--------
> +-----------+------------------+------------------+--------+-------------------
> +---------------+----------+--------------------+-----------------------------+
> ----------
> - regress_testsub4 | regress_subscription_user | f | {testpub}
> | f | off | d | f | none |
> t | f | f | off |
> dbname=regress_doesnotexist | 0/0
> +
> List of
> subscriptions
> + Name | Owner | Enabled | Publication
> | Binary | Streaming | Two-phase commit | Disable on error | Origin |
> Password required | Run as owner? | Failover | Force_alter |
> Synchronous commit | Conninfo | Skip LSN
> +------------------+---------------------------+---------+-------------+-------
> -+-----------+------------------+------------------+--------+------------------
> -+---------------+----------+-------------+--------------------+---------------
> --------------+----------
>
> The column heading should be "Force alter", as already mentioned by an
> earlier review comment (#4.7)
Yeah, fixed.
> src/test/subscription/t/099_twophase_added.pl
>
> 4.11.
>
> +# Alter the two_phase with the force_alter option. Apart from the the last
> +# ALTER SUBSCRIPTION command, the command will abort the prepared
> transaction
> +# and succeed.
>
> There is typo "the the" and the wording is a bit strange. Why not just say:
>
> SUGGESTION
> Alter the two_phase true to false with the force_alter option enabled.
> This command will succeed after aborting the prepared transaction.
Fixed.
Best Regards,
Hayato Kuroda
FUJITSU LIMITED
https://www.fujitsu.com/
Attachments:
[application/octet-stream] v10-0001-Allow-altering-of-two_phase-option-of-a-SUBSCRIP.patch (25.5K, ../../OSBPR01MB2552F66463EFCFD654E87C09F5E32@OSBPR01MB2552.jpnprd01.prod.outlook.com/2-v10-0001-Allow-altering-of-two_phase-option-of-a-SUBSCRIP.patch)
download | inline diff:
From 99884858e2b31329f19b7384d811bfd334245471 Mon Sep 17 00:00:00 2001
From: Ajin Cherian <[email protected]>
Date: Fri, 5 Apr 2024 06:47:18 -0400
Subject: [PATCH v10 1/4] Allow altering of two_phase option of a SUBSCRIPTION
This patch allows the user to alter the 'two_phase' option of a subscriber provided no
uncommitted prepared transactions are pending on that subscription.
Author: Cherian Ajin, Hayato Kuroda
---
doc/src/sgml/ref/alter_subscription.sgml | 12 ++--
src/backend/access/transam/twophase.c | 62 ++++++++++++++++
src/backend/commands/subscriptioncmds.c | 67 +++++++++++++----
.../libpqwalreceiver/libpqwalreceiver.c | 9 +--
src/backend/replication/logical/launcher.c | 22 ++++++
src/backend/replication/logical/worker.c | 21 +-----
src/backend/replication/slot.c | 18 ++++-
src/backend/replication/walsender.c | 18 ++++-
src/bin/psql/tab-complete.c | 2 +-
src/include/access/twophase.h | 5 ++
src/include/replication/slot.h | 3 +-
src/include/replication/walreceiver.h | 11 +--
src/include/replication/worker_internal.h | 1 +
src/test/regress/expected/subscription.out | 5 +-
src/test/regress/sql/subscription.sql | 5 +-
src/test/subscription/t/021_twophase.pl | 71 ++++++++++++++++++-
16 files changed, 269 insertions(+), 63 deletions(-)
diff --git a/doc/src/sgml/ref/alter_subscription.sgml b/doc/src/sgml/ref/alter_subscription.sgml
index a78c1c3a47..88e9a72147 100644
--- a/doc/src/sgml/ref/alter_subscription.sgml
+++ b/doc/src/sgml/ref/alter_subscription.sgml
@@ -68,8 +68,9 @@ ALTER SUBSCRIPTION <replaceable class="parameter">name</replaceable> RENAME TO <
<para>
Commands <command>ALTER SUBSCRIPTION ... REFRESH PUBLICATION</command>,
<command>ALTER SUBSCRIPTION ... {SET|ADD|DROP} PUBLICATION ...</command>
- with <literal>refresh</literal> option as <literal>true</literal> and
- <command>ALTER SUBSCRIPTION ... SET (failover = on|off)</command>
+ with <literal>refresh</literal> option as <literal>true</literal>,
+ <command>ALTER SUBSCRIPTION ... SET (failover = on|off)</command> and
+ <command>ALTER SUBSCRIPTION ... SET (two_phase = on|off)</command>
cannot be executed inside a transaction block.
These commands also cannot be executed when the subscription has
@@ -228,9 +229,12 @@ ALTER SUBSCRIPTION <replaceable class="parameter">name</replaceable> RENAME TO <
<link linkend="sql-createsubscription-params-with-disable-on-error"><literal>disable_on_error</literal></link>,
<link linkend="sql-createsubscription-params-with-password-required"><literal>password_required</literal></link>,
<link linkend="sql-createsubscription-params-with-run-as-owner"><literal>run_as_owner</literal></link>,
- <link linkend="sql-createsubscription-params-with-origin"><literal>origin</literal></link>, and
- <link linkend="sql-createsubscription-params-with-failover"><literal>failover</literal></link>.
+ <link linkend="sql-createsubscription-params-with-origin"><literal>origin</literal></link>,
+ <link linkend="sql-createsubscription-params-with-failover"><literal>failover</literal></link>, and
+ <link linkend="sql-createsubscription-params-with-two-phase"><literal>two_phase</literal></link>.
Only a superuser can set <literal>password_required = false</literal>.
+ The <literal>two_phase</literal> parameter can only be altered when the
+ subscription is disabled.
</para>
<para>
diff --git a/src/backend/access/transam/twophase.c b/src/backend/access/transam/twophase.c
index 8090ac9fc1..66fa591eb5 100644
--- a/src/backend/access/transam/twophase.c
+++ b/src/backend/access/transam/twophase.c
@@ -2682,3 +2682,65 @@ LookupGXact(const char *gid, XLogRecPtr prepare_end_lsn,
LWLockRelease(TwoPhaseStateLock);
return found;
}
+
+/*
+ * TwoPhaseTransactionGid
+ * Form the prepared transaction GID for two_phase transactions.
+ *
+ * Return the GID in the supplied buffer.
+ */
+void
+TwoPhaseTransactionGid(Oid subid, TransactionId xid, char *gid, int szgid)
+{
+ Assert(subid != InvalidRepOriginId);
+
+ if (!TransactionIdIsValid(xid))
+ ereport(ERROR,
+ (errcode(ERRCODE_PROTOCOL_VIOLATION),
+ errmsg_internal("invalid two-phase transaction ID")));
+
+ snprintf(gid, szgid, "pg_gid_%u_%u", subid, xid);
+}
+
+/*
+ * IsTwoPhaseTransactionGidForSubid
+ * Check whether the given GID (as formed by TwoPhaseTransactionGid) is
+ * for the specified 'subid'.
+ */
+static bool
+IsTwoPhaseTransactionGidForSubid(Oid subid, char *gid)
+{
+ int ret;
+ Oid subid_written;
+ TransactionId xid;
+
+ ret = sscanf(gid, "pg_gid_%u_%u", &subid_written, &xid);
+
+ return (ret == 2 && subid == subid_written);
+}
+
+/*
+ * LookupGXactBySubid
+ * Check if the prepared transaction done by apply worker exists.
+ */
+bool
+LookupGXactBySubid(Oid subid)
+{
+ bool found = false;
+
+ LWLockAcquire(TwoPhaseStateLock, LW_SHARED);
+ for (int i = 0; i < TwoPhaseState->numPrepXacts; i++)
+ {
+ GlobalTransaction gxact = TwoPhaseState->prepXacts[i];
+
+ /* Ignore not-yet-valid GIDs. */
+ if (gxact->valid &&
+ IsTwoPhaseTransactionGidForSubid(subid, gxact->gid))
+ {
+ found = true;
+ break;
+ }
+ }
+ LWLockRelease(TwoPhaseStateLock);
+ return found;
+}
diff --git a/src/backend/commands/subscriptioncmds.c b/src/backend/commands/subscriptioncmds.c
index e407428dbc..90d967eb7c 100644
--- a/src/backend/commands/subscriptioncmds.c
+++ b/src/backend/commands/subscriptioncmds.c
@@ -16,6 +16,7 @@
#include "access/htup_details.h"
#include "access/table.h"
+#include "access/twophase.h"
#include "access/xact.h"
#include "catalog/catalog.h"
#include "catalog/dependency.h"
@@ -1143,7 +1144,8 @@ AlterSubscription(ParseState *pstate, AlterSubscriptionStmt *stmt,
{
supported_opts = (SUBOPT_SLOT_NAME |
SUBOPT_SYNCHRONOUS_COMMIT | SUBOPT_BINARY |
- SUBOPT_STREAMING | SUBOPT_DISABLE_ON_ERR |
+ SUBOPT_STREAMING | SUBOPT_TWOPHASE_COMMIT |
+ SUBOPT_DISABLE_ON_ERR |
SUBOPT_PASSWORD_REQUIRED |
SUBOPT_RUN_AS_OWNER | SUBOPT_FAILOVER |
SUBOPT_ORIGIN);
@@ -1151,6 +1153,52 @@ AlterSubscription(ParseState *pstate, AlterSubscriptionStmt *stmt,
parse_subscription_options(pstate, stmt->options,
supported_opts, &opts);
+ if (IsSet(opts.specified_opts, SUBOPT_TWOPHASE_COMMIT))
+ {
+ /*
+ * Do not allow changing the two_phase option if the
+ * subscription is enabled. This is because the two_phase
+ * option of the slot on the publisher cannot be modified
+ * if the slot is currently acquired by the apply worker.
+ */
+ if (form->subenabled)
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("cannot set %s for enabled subscription",
+ "two_phase")));
+
+ /*
+ * Stop all the subscription workers, just in case. Workers
+ * may still survive even if the subscription is disabled.
+ */
+ logicalrep_workers_stop(subid);
+
+ /*
+ * two_phase cannot be disabled if there are any
+ * uncommitted prepared transactions present.
+ */
+ if (!opts.twophase &&
+ form->subtwophasestate == LOGICALREP_TWOPHASE_STATE_ENABLED &&
+ LookupGXactBySubid(subid))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("cannot disable two_phase when uncommitted prepared transactions present"),
+ errhint("Resolve these transactions and try again")));
+
+ /*
+ * The changed two_phase option of the slot can't be rolled
+ * back.
+ */
+ PreventInTransactionBlock(isTopLevel, "ALTER SUBSCRIPTION ... SET (two_phase)");
+
+ /* Change system catalog acoordingly */
+ values[Anum_pg_subscription_subtwophasestate - 1] =
+ CharGetDatum(opts.twophase ?
+ LOGICALREP_TWOPHASE_STATE_PENDING :
+ LOGICALREP_TWOPHASE_STATE_DISABLED);
+ replaces[Anum_pg_subscription_subtwophasestate - 1] = true;
+ }
+
if (IsSet(opts.specified_opts, SUBOPT_SLOT_NAME))
{
/*
@@ -1505,7 +1553,8 @@ AlterSubscription(ParseState *pstate, AlterSubscriptionStmt *stmt,
* doing the database operations we won't be able to rollback altered
* slot.
*/
- if (replaces[Anum_pg_subscription_subfailover - 1])
+ if (replaces[Anum_pg_subscription_subfailover - 1] ||
+ replaces[Anum_pg_subscription_subtwophasestate - 1])
{
bool must_use_password;
char *err;
@@ -1525,7 +1574,7 @@ AlterSubscription(ParseState *pstate, AlterSubscriptionStmt *stmt,
PG_TRY();
{
- walrcv_alter_slot(wrconn, sub->slotname, opts.failover);
+ walrcv_alter_slot(wrconn, sub->slotname, opts.failover, opts.twophase);
}
PG_FINALLY();
{
@@ -1562,7 +1611,6 @@ DropSubscription(DropSubscriptionStmt *stmt, bool isTopLevel)
char *subname;
char *conninfo;
char *slotname;
- List *subworkers;
ListCell *lc;
char originname[NAMEDATALEN];
char *err = NULL;
@@ -1672,16 +1720,7 @@ DropSubscription(DropSubscriptionStmt *stmt, bool isTopLevel)
* New workers won't be started because we hold an exclusive lock on the
* subscription till the end of the transaction.
*/
- LWLockAcquire(LogicalRepWorkerLock, LW_SHARED);
- subworkers = logicalrep_workers_find(subid, false);
- LWLockRelease(LogicalRepWorkerLock);
- foreach(lc, subworkers)
- {
- LogicalRepWorker *w = (LogicalRepWorker *) lfirst(lc);
-
- logicalrep_worker_stop(w->subid, w->relid);
- }
- list_free(subworkers);
+ logicalrep_workers_stop(subid);
/*
* Remove the no-longer-useful entry in the launcher's table of apply
diff --git a/src/backend/replication/libpqwalreceiver/libpqwalreceiver.c b/src/backend/replication/libpqwalreceiver/libpqwalreceiver.c
index 3c2b1bb496..998bbd517a 100644
--- a/src/backend/replication/libpqwalreceiver/libpqwalreceiver.c
+++ b/src/backend/replication/libpqwalreceiver/libpqwalreceiver.c
@@ -80,7 +80,7 @@ static char *libpqrcv_create_slot(WalReceiverConn *conn,
CRSSnapshotAction snapshot_action,
XLogRecPtr *lsn);
static void libpqrcv_alter_slot(WalReceiverConn *conn, const char *slotname,
- bool failover);
+ bool failover, bool two_phase);
static pid_t libpqrcv_get_backend_pid(WalReceiverConn *conn);
static WalRcvExecResult *libpqrcv_exec(WalReceiverConn *conn,
const char *query,
@@ -1121,15 +1121,16 @@ libpqrcv_create_slot(WalReceiverConn *conn, const char *slotname,
*/
static void
libpqrcv_alter_slot(WalReceiverConn *conn, const char *slotname,
- bool failover)
+ bool failover, bool two_phase)
{
StringInfoData cmd;
PGresult *res;
initStringInfo(&cmd);
- appendStringInfo(&cmd, "ALTER_REPLICATION_SLOT %s ( FAILOVER %s )",
+ appendStringInfo(&cmd, "ALTER_REPLICATION_SLOT %s ( FAILOVER %s, TWO_PHASE %s )",
quote_identifier(slotname),
- failover ? "true" : "false");
+ failover ? "true" : "false",
+ two_phase ? "true" : "false");
res = libpqrcv_PQexec(conn->streamConn, cmd.data);
pfree(cmd.data);
diff --git a/src/backend/replication/logical/launcher.c b/src/backend/replication/logical/launcher.c
index 66070e9131..548f6e0edb 100644
--- a/src/backend/replication/logical/launcher.c
+++ b/src/backend/replication/logical/launcher.c
@@ -623,6 +623,28 @@ logicalrep_worker_stop(Oid subid, Oid relid)
LWLockRelease(LogicalRepWorkerLock);
}
+/*
+ * Stop all the subscription workers.
+ */
+void
+logicalrep_workers_stop(Oid subid)
+{
+ List *subworkers;
+ ListCell *lc;
+
+ LWLockAcquire(LogicalRepWorkerLock, LW_SHARED);
+ /* XXX clarify the reason why not only running workers are listed. */
+ subworkers = logicalrep_workers_find(subid, false);
+ LWLockRelease(LogicalRepWorkerLock);
+ foreach(lc, subworkers)
+ {
+ LogicalRepWorker *w = (LogicalRepWorker *) lfirst(lc);
+
+ logicalrep_worker_stop(w->subid, w->relid);
+ }
+ list_free(subworkers);
+}
+
/*
* Stop the given logical replication parallel apply worker.
*
diff --git a/src/backend/replication/logical/worker.c b/src/backend/replication/logical/worker.c
index b5a80fe3e8..dcf656fd45 100644
--- a/src/backend/replication/logical/worker.c
+++ b/src/backend/replication/logical/worker.c
@@ -402,7 +402,6 @@ static void apply_handle_tuple_routing(ApplyExecutionData *edata,
CmdType operation);
/* Compute GID for two_phase transactions */
-static void TwoPhaseTransactionGid(Oid subid, TransactionId xid, char *gid, int szgid);
/* Functions for skipping changes */
static void maybe_start_skipping_changes(XLogRecPtr finish_lsn);
@@ -3911,7 +3910,7 @@ maybe_reread_subscription(void)
/* !slotname should never happen when enabled is true. */
Assert(newsub->slotname);
- /* two-phase should not be altered */
+ /* two-phase cannot be altered while the worker exists */
Assert(newsub->twophasestate == MySubscription->twophasestate);
/*
@@ -4396,24 +4395,6 @@ cleanup_subxact_info()
subxact_data.nsubxacts_max = 0;
}
-/*
- * Form the prepared transaction GID for two_phase transactions.
- *
- * Return the GID in the supplied buffer.
- */
-static void
-TwoPhaseTransactionGid(Oid subid, TransactionId xid, char *gid, int szgid)
-{
- Assert(subid != InvalidRepOriginId);
-
- if (!TransactionIdIsValid(xid))
- ereport(ERROR,
- (errcode(ERRCODE_PROTOCOL_VIOLATION),
- errmsg_internal("invalid two-phase transaction ID")));
-
- snprintf(gid, szgid, "pg_gid_%u_%u", subid, xid);
-}
-
/*
* Common function to run the apply loop with error handling. Disable the
* subscription, if necessary.
diff --git a/src/backend/replication/slot.c b/src/backend/replication/slot.c
index aa4ea387da..d0c8d5a4df 100644
--- a/src/backend/replication/slot.c
+++ b/src/backend/replication/slot.c
@@ -804,8 +804,10 @@ ReplicationSlotDrop(const char *name, bool nowait)
* Change the definition of the slot identified by the specified name.
*/
void
-ReplicationSlotAlter(const char *name, bool failover)
+ReplicationSlotAlter(const char *name, bool failover, bool two_phase)
{
+ bool update_slot = false;
+
Assert(MyReplicationSlot == NULL);
ReplicationSlotAcquire(name, false);
@@ -854,6 +856,20 @@ ReplicationSlotAlter(const char *name, bool failover)
MyReplicationSlot->data.failover = failover;
SpinLockRelease(&MyReplicationSlot->mutex);
+ update_slot = true;
+ }
+
+ if (MyReplicationSlot->data.two_phase != two_phase)
+ {
+ SpinLockAcquire(&MyReplicationSlot->mutex);
+ MyReplicationSlot->data.two_phase = two_phase;
+ SpinLockRelease(&MyReplicationSlot->mutex);
+
+ update_slot = true;
+ }
+
+ if (update_slot)
+ {
ReplicationSlotMarkDirty();
ReplicationSlotSave();
}
diff --git a/src/backend/replication/walsender.c b/src/backend/replication/walsender.c
index c623b07cf0..2e6ca35049 100644
--- a/src/backend/replication/walsender.c
+++ b/src/backend/replication/walsender.c
@@ -1411,9 +1411,11 @@ DropReplicationSlot(DropReplicationSlotCmd *cmd)
* Process extra options given to ALTER_REPLICATION_SLOT.
*/
static void
-ParseAlterReplSlotOptions(AlterReplicationSlotCmd *cmd, bool *failover)
+ParseAlterReplSlotOptions(AlterReplicationSlotCmd *cmd,
+ bool *failover, bool *two_phase)
{
bool failover_given = false;
+ bool two_phase_given = false;
/* Parse options */
foreach_ptr(DefElem, defel, cmd->options)
@@ -1427,6 +1429,15 @@ ParseAlterReplSlotOptions(AlterReplicationSlotCmd *cmd, bool *failover)
failover_given = true;
*failover = defGetBoolean(defel);
}
+ else if (strcmp(defel->defname, "two_phase") == 0)
+ {
+ if (two_phase_given)
+ ereport(ERROR,
+ (errcode(ERRCODE_SYNTAX_ERROR),
+ errmsg("conflicting or redundant options")));
+ two_phase_given = true;
+ *two_phase = defGetBoolean(defel);
+ }
else
elog(ERROR, "unrecognized option: %s", defel->defname);
}
@@ -1439,9 +1450,10 @@ static void
AlterReplicationSlot(AlterReplicationSlotCmd *cmd)
{
bool failover = false;
+ bool two_phase = false;
- ParseAlterReplSlotOptions(cmd, &failover);
- ReplicationSlotAlter(cmd->slotname, failover);
+ ParseAlterReplSlotOptions(cmd, &failover, &two_phase);
+ ReplicationSlotAlter(cmd->slotname, failover, two_phase);
}
/*
diff --git a/src/bin/psql/tab-complete.c b/src/bin/psql/tab-complete.c
index d453e224d9..891face1b6 100644
--- a/src/bin/psql/tab-complete.c
+++ b/src/bin/psql/tab-complete.c
@@ -1948,7 +1948,7 @@ psql_completion(const char *text, int start, int end)
else if (HeadMatches("ALTER", "SUBSCRIPTION", MatchAny) && TailMatches("SET", "("))
COMPLETE_WITH("binary", "disable_on_error", "failover", "origin",
"password_required", "run_as_owner", "slot_name",
- "streaming", "synchronous_commit");
+ "streaming", "synchronous_commit", "two_phase");
/* ALTER SUBSCRIPTION <name> SKIP ( */
else if (HeadMatches("ALTER", "SUBSCRIPTION", MatchAny) && TailMatches("SKIP", "("))
COMPLETE_WITH("lsn");
diff --git a/src/include/access/twophase.h b/src/include/access/twophase.h
index 56248c0006..d37e06fdee 100644
--- a/src/include/access/twophase.h
+++ b/src/include/access/twophase.h
@@ -62,4 +62,9 @@ extern void PrepareRedoRemove(TransactionId xid, bool giveWarning);
extern void restoreTwoPhaseData(void);
extern bool LookupGXact(const char *gid, XLogRecPtr prepare_end_lsn,
TimestampTz origin_prepare_timestamp);
+
+extern void TwoPhaseTransactionGid(Oid subid, TransactionId xid, char *gid,
+ int szgid);
+extern bool LookupGXactBySubid(Oid subid);
+
#endif /* TWOPHASE_H */
diff --git a/src/include/replication/slot.h b/src/include/replication/slot.h
index 1bc80960ef..014e216cf5 100644
--- a/src/include/replication/slot.h
+++ b/src/include/replication/slot.h
@@ -243,7 +243,8 @@ extern void ReplicationSlotCreate(const char *name, bool db_specific,
extern void ReplicationSlotPersist(void);
extern void ReplicationSlotDrop(const char *name, bool nowait);
extern void ReplicationSlotDropAcquired(void);
-extern void ReplicationSlotAlter(const char *name, bool failover);
+extern void ReplicationSlotAlter(const char *name, bool failover,
+ bool two_phase);
extern void ReplicationSlotAcquire(const char *name, bool nowait);
extern void ReplicationSlotRelease(void);
diff --git a/src/include/replication/walreceiver.h b/src/include/replication/walreceiver.h
index 12f71fa99b..31fa1257ec 100644
--- a/src/include/replication/walreceiver.h
+++ b/src/include/replication/walreceiver.h
@@ -372,12 +372,13 @@ typedef char *(*walrcv_create_slot_fn) (WalReceiverConn *conn,
/*
* walrcv_alter_slot_fn
*
- * Change the definition of a replication slot. Currently, it only supports
- * changing the failover property of the slot.
+ * Change the definition of a replication slot. Currently, it supports
+ * changing the failover and the two_phase property of the slot.
*/
typedef void (*walrcv_alter_slot_fn) (WalReceiverConn *conn,
const char *slotname,
- bool failover);
+ bool failover,
+ bool two_phase);
/*
* walrcv_get_backend_pid_fn
@@ -455,8 +456,8 @@ extern PGDLLIMPORT WalReceiverFunctionsType *WalReceiverFunctions;
WalReceiverFunctions->walrcv_send(conn, buffer, nbytes)
#define walrcv_create_slot(conn, slotname, temporary, two_phase, failover, snapshot_action, lsn) \
WalReceiverFunctions->walrcv_create_slot(conn, slotname, temporary, two_phase, failover, snapshot_action, lsn)
-#define walrcv_alter_slot(conn, slotname, failover) \
- WalReceiverFunctions->walrcv_alter_slot(conn, slotname, failover)
+#define walrcv_alter_slot(conn, slotname, failover, two_phase) \
+ WalReceiverFunctions->walrcv_alter_slot(conn, slotname, failover, two_phase)
#define walrcv_get_backend_pid(conn) \
WalReceiverFunctions->walrcv_get_backend_pid(conn)
#define walrcv_exec(conn, exec, nRetTypes, retTypes) \
diff --git a/src/include/replication/worker_internal.h b/src/include/replication/worker_internal.h
index 515aefd519..d5428263c1 100644
--- a/src/include/replication/worker_internal.h
+++ b/src/include/replication/worker_internal.h
@@ -246,6 +246,7 @@ extern bool logicalrep_worker_launch(LogicalRepWorkerType wtype,
Oid userid, Oid relid,
dsm_handle subworker_dsm);
extern void logicalrep_worker_stop(Oid subid, Oid relid);
+extern void logicalrep_workers_stop(Oid subid);
extern void logicalrep_pa_worker_stop(ParallelApplyWorkerInfo *winfo);
extern void logicalrep_worker_wakeup(Oid subid, Oid relid);
extern void logicalrep_worker_wakeup_ptr(LogicalRepWorker *worker);
diff --git a/src/test/regress/expected/subscription.out b/src/test/regress/expected/subscription.out
index 0f2a25cdc1..51fa4b9690 100644
--- a/src/test/regress/expected/subscription.out
+++ b/src/test/regress/expected/subscription.out
@@ -377,10 +377,7 @@ HINT: To initiate replication, you must manually create the replication slot, e
regress_testsub | regress_subscription_user | f | {testpub} | f | off | p | f | any | t | f | f | off | dbname=regress_doesnotexist | 0/0
(1 row)
---fail - alter of two_phase option not supported.
-ALTER SUBSCRIPTION regress_testsub SET (two_phase = false);
-ERROR: unrecognized subscription parameter: "two_phase"
--- but can alter streaming when two_phase enabled
+-- We can alter streaming when two_phase enabled
ALTER SUBSCRIPTION regress_testsub SET (streaming = true);
\dRs+
List of subscriptions
diff --git a/src/test/regress/sql/subscription.sql b/src/test/regress/sql/subscription.sql
index 3e5ba4cb8c..a3886d79ca 100644
--- a/src/test/regress/sql/subscription.sql
+++ b/src/test/regress/sql/subscription.sql
@@ -256,10 +256,7 @@ CREATE SUBSCRIPTION regress_testsub CONNECTION 'dbname=regress_doesnotexist' PUB
CREATE SUBSCRIPTION regress_testsub CONNECTION 'dbname=regress_doesnotexist' PUBLICATION testpub WITH (connect = false, two_phase = true);
\dRs+
---fail - alter of two_phase option not supported.
-ALTER SUBSCRIPTION regress_testsub SET (two_phase = false);
-
--- but can alter streaming when two_phase enabled
+-- We can alter streaming when two_phase enabled
ALTER SUBSCRIPTION regress_testsub SET (streaming = true);
\dRs+
diff --git a/src/test/subscription/t/021_twophase.pl b/src/test/subscription/t/021_twophase.pl
index 9437cd4c3b..72df258000 100644
--- a/src/test/subscription/t/021_twophase.pl
+++ b/src/test/subscription/t/021_twophase.pl
@@ -367,6 +367,75 @@ $result =
$node_subscriber->safe_psql('postgres', "SELECT count(*) FROM tab_copy;");
is($result, qq(2), 'replicated data in subscriber table');
+# Clean up
+$node_subscriber->safe_psql('postgres', "DROP SUBSCRIPTION tap_sub");
+
+###############################
+# Disable the subscription and alter it to two_phase = false,
+# then verify that the altered subscription reflects the two_phase option.
+###############################
+
+# Alter subscription two_phase to false
+$node_subscriber->safe_psql('postgres',
+ "ALTER SUBSCRIPTION tap_sub_copy DISABLE");
+$node_subscriber->safe_psql('postgres',
+ "ALTER SUBSCRIPTION tap_sub_copy SET (two_phase = false)");
+$node_subscriber->safe_psql('postgres',
+ "ALTER SUBSCRIPTION tap_sub_copy ENABLE");
+
+# Wait for subscription startup
+$node_subscriber->wait_for_subscription_sync($node_publisher, $appname_copy);
+
+# Make sure that the two-phase is disabled on the subscriber
+$result = $node_subscriber->safe_psql('postgres',
+ "SELECT subtwophasestate FROM pg_subscription WHERE subname = 'tap_sub_copy';"
+);
+is($result, qq(d), 'two-phase should be disabled');
+
+# Now do a prepare on the publisher and make sure that it is not replicated.
+$node_publisher->safe_psql(
+ 'postgres', qq{
+ BEGIN;
+ INSERT INTO tab_copy VALUES (100);
+ PREPARE TRANSACTION 'newgid';
+ });
+
+# Wait for the subscriber to catchup
+$node_publisher->wait_for_catchup($appname_copy);
+
+# Make sure there are no prepared transactions on the subscriber
+$result = $node_subscriber->safe_psql('postgres',
+ "SELECT count(*) FROM pg_prepared_xacts;");
+is($result, qq(0), 'should be no prepared transactions on subscriber');
+
+# Now commit the insert and verify that it IS replicated
+$node_publisher->safe_psql('postgres', "COMMIT PREPARED 'newgid';");
+
+# Wait for the subscriber to catchup
+$node_publisher->wait_for_catchup($appname_copy);
+
+# Make sure that the committed transaction is replicated.
+$result =
+ $node_subscriber->safe_psql('postgres', "SELECT count(*) FROM tab_copy;");
+is($result, qq(3), 'replicated data in subscriber table');
+
+# Alter subscription two_phase to true
+$node_subscriber->safe_psql('postgres',
+ "ALTER SUBSCRIPTION tap_sub_copy DISABLE");
+$node_subscriber->safe_psql('postgres',
+ "ALTER SUBSCRIPTION tap_sub_copy SET (two_phase = true)");
+$node_subscriber->safe_psql('postgres',
+ "ALTER SUBSCRIPTION tap_sub_copy ENABLE");
+
+# Wait for subscription startup
+$node_subscriber->wait_for_subscription_sync($node_publisher, $appname_copy);
+
+# Make sure that the two-phase is enabled on the subscriber
+$result = $node_subscriber->safe_psql('postgres',
+ "SELECT subtwophasestate FROM pg_subscription WHERE subname = 'tap_sub_copy';"
+);
+is($result, qq(e), 'two-phase should be enabled');
+
$node_subscriber->safe_psql('postgres', "DROP SUBSCRIPTION tap_sub_copy;");
$node_publisher->safe_psql('postgres', "DROP PUBLICATION tap_pub_copy;");
@@ -374,8 +443,6 @@ $node_publisher->safe_psql('postgres', "DROP PUBLICATION tap_pub_copy;");
# check all the cleanup
###############################
-$node_subscriber->safe_psql('postgres', "DROP SUBSCRIPTION tap_sub");
-
$result = $node_subscriber->safe_psql('postgres',
"SELECT count(*) FROM pg_subscription");
is($result, qq(0), 'check subscription was dropped on subscriber');
--
2.43.0
[application/octet-stream] v10-0002-Alter-slot-option-two_phase-only-when-altering-t.patch (12.2K, ../../OSBPR01MB2552F66463EFCFD654E87C09F5E32@OSBPR01MB2552.jpnprd01.prod.outlook.com/3-v10-0002-Alter-slot-option-two_phase-only-when-altering-t.patch)
download | inline diff:
From be161c6fcc17161b66f4d4b342b98f5b3de25ebf Mon Sep 17 00:00:00 2001
From: Hayato Kuroda <[email protected]>
Date: Wed, 17 Apr 2024 06:18:23 +0000
Subject: [PATCH v10 2/4] Alter slot option two_phase only when altering "true"
to "false"
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit
Since the two_phase option is controlled by both the publisher (as a slot option)
and the subscriber (as a subscription option), the slot option must also be
modified.
Regarding the false->true case, the backend process alters the subtwophase to
LOGICALREP_TWOPHASE_STATE_PENDING once. After the subscription is enabled, a new
logical replication worker requests to change the two_phase option of its slot
from pending to true after the initial data synchronization is done. The code
path is the same as the case in which two_phase is initially set to true, so
there is no need to do something remarkable. However, for the true->false case,
the backend must connect to the publisher and expressly change the parameter
because the apply worker does not alter the option to false. The operation cannot
be rolled back, and altering the parameter from "true" to "false" within a
transaction is prohibited.
---
doc/src/sgml/ref/alter_subscription.sgml | 2 +-
src/backend/commands/subscriptioncmds.c | 42 ++++++--
.../libpqwalreceiver/libpqwalreceiver.c | 23 +++--
src/include/replication/walreceiver.h | 5 +-
src/test/subscription/meson.build | 1 +
src/test/subscription/t/099_twophase_added.pl | 96 +++++++++++++++++++
6 files changed, 153 insertions(+), 16 deletions(-)
create mode 100644 src/test/subscription/t/099_twophase_added.pl
diff --git a/doc/src/sgml/ref/alter_subscription.sgml b/doc/src/sgml/ref/alter_subscription.sgml
index 88e9a72147..0c2894a94e 100644
--- a/doc/src/sgml/ref/alter_subscription.sgml
+++ b/doc/src/sgml/ref/alter_subscription.sgml
@@ -70,7 +70,7 @@ ALTER SUBSCRIPTION <replaceable class="parameter">name</replaceable> RENAME TO <
<command>ALTER SUBSCRIPTION ... {SET|ADD|DROP} PUBLICATION ...</command>
with <literal>refresh</literal> option as <literal>true</literal>,
<command>ALTER SUBSCRIPTION ... SET (failover = on|off)</command> and
- <command>ALTER SUBSCRIPTION ... SET (two_phase = on|off)</command>
+ <command>ALTER SUBSCRIPTION ... SET (two_phase = off)</command>
cannot be executed inside a transaction block.
These commands also cannot be executed when the subscription has
diff --git a/src/backend/commands/subscriptioncmds.c b/src/backend/commands/subscriptioncmds.c
index 90d967eb7c..d9abf687d1 100644
--- a/src/backend/commands/subscriptioncmds.c
+++ b/src/backend/commands/subscriptioncmds.c
@@ -1097,6 +1097,8 @@ AlterSubscription(ParseState *pstate, AlterSubscriptionStmt *stmt,
Form_pg_subscription form;
bits32 supported_opts;
SubOpts opts = {0};
+ bool update_failover;
+ bool update_two_phase;
rel = table_open(SubscriptionRelationId, RowExclusiveLock);
@@ -1186,10 +1188,24 @@ AlterSubscription(ParseState *pstate, AlterSubscriptionStmt *stmt,
errhint("Resolve these transactions and try again")));
/*
- * The changed two_phase option of the slot can't be rolled
- * back.
+ * Altering the parameter from "true" to "false" within a
+ * transaction is prohibited. Since the apply worker does
+ * not alter the slot option to false, the backend must
+ * connect to the publisher and expressly change the
+ * parameter.
+ *
+ * There is no need to do something remarkable regarding
+ * the "false" to "true" case; the backend process alters
+ * subtwophase to LOGICALREP_TWOPHASE_STATE_PENDING once.
+ * After the subscription is enabled, a new logical
+ * replication worker requests to change the two_phase
+ * option of its slot when the initial data synchronization
+ * is done. The code path is the same as the case in which
+ * two_phase is initially set to true.
*/
- PreventInTransactionBlock(isTopLevel, "ALTER SUBSCRIPTION ... SET (two_phase)");
+ if (!opts.twophase)
+ PreventInTransactionBlock(isTopLevel,
+ "ALTER SUBSCRIPTION ... SET (two_phase = false)");
/* Change system catalog acoordingly */
values[Anum_pg_subscription_subtwophasestate - 1] =
@@ -1547,14 +1563,24 @@ AlterSubscription(ParseState *pstate, AlterSubscriptionStmt *stmt,
}
/*
- * Try to acquire the connection necessary for altering slot.
+ * Check the need to alter the replication slot. Failover and two_phase
+ * options are controlled by both the publisher (as a slot option) and the
+ * subscriber (as a subscription option). The slot option must be altered
+ * only when changing "true" to "false". The reason has already been
+ * described in the ALTER_SUBSCRIPTION_OPTIONS section of this function.
+ */
+ update_failover = replaces[Anum_pg_subscription_subfailover - 1];
+ update_two_phase = (replaces[Anum_pg_subscription_subtwophasestate - 1] &&
+ !opts.twophase);
+
+ /*
+ * Try to acquire the connection necessary for altering slot, if needed.
*
* This has to be at the end because otherwise if there is an error while
* doing the database operations we won't be able to rollback altered
* slot.
*/
- if (replaces[Anum_pg_subscription_subfailover - 1] ||
- replaces[Anum_pg_subscription_subtwophasestate - 1])
+ if (update_failover || update_two_phase)
{
bool must_use_password;
char *err;
@@ -1574,7 +1600,9 @@ AlterSubscription(ParseState *pstate, AlterSubscriptionStmt *stmt,
PG_TRY();
{
- walrcv_alter_slot(wrconn, sub->slotname, opts.failover, opts.twophase);
+ walrcv_alter_slot(wrconn, sub->slotname,
+ update_failover ? &opts.failover : NULL,
+ update_two_phase ? &opts.twophase : NULL);
}
PG_FINALLY();
{
diff --git a/src/backend/replication/libpqwalreceiver/libpqwalreceiver.c b/src/backend/replication/libpqwalreceiver/libpqwalreceiver.c
index 998bbd517a..ff013aa987 100644
--- a/src/backend/replication/libpqwalreceiver/libpqwalreceiver.c
+++ b/src/backend/replication/libpqwalreceiver/libpqwalreceiver.c
@@ -80,7 +80,7 @@ static char *libpqrcv_create_slot(WalReceiverConn *conn,
CRSSnapshotAction snapshot_action,
XLogRecPtr *lsn);
static void libpqrcv_alter_slot(WalReceiverConn *conn, const char *slotname,
- bool failover, bool two_phase);
+ const bool *failover, const bool *two_phase);
static pid_t libpqrcv_get_backend_pid(WalReceiverConn *conn);
static WalRcvExecResult *libpqrcv_exec(WalReceiverConn *conn,
const char *query,
@@ -1121,16 +1121,27 @@ libpqrcv_create_slot(WalReceiverConn *conn, const char *slotname,
*/
static void
libpqrcv_alter_slot(WalReceiverConn *conn, const char *slotname,
- bool failover, bool two_phase)
+ const bool *failover, const bool *two_phase)
{
StringInfoData cmd;
PGresult *res;
initStringInfo(&cmd);
- appendStringInfo(&cmd, "ALTER_REPLICATION_SLOT %s ( FAILOVER %s, TWO_PHASE %s )",
- quote_identifier(slotname),
- failover ? "true" : "false",
- two_phase ? "true" : "false");
+ appendStringInfo(&cmd, "ALTER_REPLICATION_SLOT %s ( ",
+ quote_identifier(slotname));
+
+ if (failover)
+ appendStringInfo(&cmd, "FAILOVER %s",
+ *failover ? "true" : "false");
+
+ if (failover && two_phase)
+ appendStringInfo(&cmd, ", ");
+
+ if (two_phase)
+ appendStringInfo(&cmd, "TWO_PHASE %s",
+ *two_phase ? "true" : "false");
+
+ appendStringInfoString(&cmd, " );");
res = libpqrcv_PQexec(conn->streamConn, cmd.data);
pfree(cmd.data);
diff --git a/src/include/replication/walreceiver.h b/src/include/replication/walreceiver.h
index 31fa1257ec..7ffa5a58b3 100644
--- a/src/include/replication/walreceiver.h
+++ b/src/include/replication/walreceiver.h
@@ -377,8 +377,9 @@ typedef char *(*walrcv_create_slot_fn) (WalReceiverConn *conn,
*/
typedef void (*walrcv_alter_slot_fn) (WalReceiverConn *conn,
const char *slotname,
- bool failover,
- bool two_phase);
+ const bool *failover,
+ const bool *two_phase);
+
/*
* walrcv_get_backend_pid_fn
diff --git a/src/test/subscription/meson.build b/src/test/subscription/meson.build
index c591cd7d61..b4bd522c3d 100644
--- a/src/test/subscription/meson.build
+++ b/src/test/subscription/meson.build
@@ -40,6 +40,7 @@ tests += {
't/031_column_list.pl',
't/032_subscribe_use_index.pl',
't/033_run_as_table_owner.pl',
+ 't/099_twophase_added.pl',
't/100_bugs.pl',
],
},
diff --git a/src/test/subscription/t/099_twophase_added.pl b/src/test/subscription/t/099_twophase_added.pl
new file mode 100644
index 0000000000..b7c97f8454
--- /dev/null
+++ b/src/test/subscription/t/099_twophase_added.pl
@@ -0,0 +1,96 @@
+# Copyright (c) 2024, PostgreSQL Global Development Group
+
+# Additional tests for altering two_phase option
+use strict;
+use warnings FATAL => 'all';
+use PostgreSQL::Test::Cluster;
+use PostgreSQL::Test::Utils;
+use Test::More;
+
+# Initialize publisher node
+my $node_publisher = PostgreSQL::Test::Cluster->new('publisher');
+$node_publisher->init(allows_streaming => 'logical');
+$node_publisher->append_conf('postgresql.conf',
+ qq(max_prepared_transactions = 10));
+$node_publisher->start;
+
+# Create subscriber node
+my $node_subscriber = PostgreSQL::Test::Cluster->new('subscriber');
+$node_subscriber->init;
+$node_subscriber->append_conf('postgresql.conf',
+ qq(max_prepared_transactions = 10
+ log_min_messages = debug1));
+$node_subscriber->start;
+
+# Define tables on both nodes
+$node_publisher->safe_psql('postgres',
+ "CREATE TABLE tab_full (a int PRIMARY KEY);");
+$node_subscriber->safe_psql('postgres',
+ "CREATE TABLE tab_full (a int PRIMARY KEY)");
+
+# Setup logical replication, with two_phase = "false"
+my $publisher_connstr = $node_publisher->connstr . ' dbname=postgres';
+$node_publisher->safe_psql('postgres',
+ "CREATE PUBLICATION pub FOR ALL TABLES");
+
+my $log_offset = -s $node_subscriber->logfile;
+
+$node_subscriber->safe_psql(
+ 'postgres', "
+ CREATE SUBSCRIPTION regress_sub
+ CONNECTION '$publisher_connstr' PUBLICATION pub
+ WITH (two_phase = false, copy_data = false, failover = false)");
+
+# Verify the started worker recognized two_phase was disabled
+$node_subscriber->wait_for_log(
+ 'logical replication apply worker for subscription "regress_sub" two_phase is DISABLED', $log_offset);
+
+#####################
+# Check the case that prepared transactions exist on the publisher node.
+#
+# Since the two_phase is "off", then normally, this PREPARE will do nothing
+# until the COMMIT PREPARED, but in this test, we toggle the two_phase to
+# "true" again before the COMMIT PREPARED happens.
+
+# Prepare a transaction to insert some tuples into the table
+$node_publisher->safe_psql(
+ 'postgres', "
+ BEGIN;
+ INSERT INTO tab_full VALUES (generate_series(1, 5));
+ PREPARE TRANSACTION 'test_prepared_tab_full';");
+
+$node_publisher->wait_for_catchup('regress_sub');
+
+# Verify the prepared transaction is not yet replicated to the subscriber
+# because two_phase is set to "false".
+my $result = $node_subscriber->safe_psql('postgres',
+ "SELECT count(*) FROM pg_prepared_xacts;");
+is($result, q(0), "transaction is not prepared on subscriber");
+
+$log_offset = -s $node_subscriber->logfile;
+
+# Toggle the two_phase to "true" *before* the COMMIT PREPARED. Since we are the
+# special path for the case where both two_phase and failover are altered, it
+# is also set to "true".
+$node_subscriber->safe_psql(
+ 'postgres', "
+ ALTER SUBSCRIPTION regress_sub DISABLE;
+ ALTER SUBSCRIPTION regress_sub SET (two_phase = true, failover = true);
+ ALTER SUBSCRIPTION regress_sub ENABLE;");
+
+# Verify the started worker recognized two_phase was enabled
+$node_subscriber->wait_for_log(
+ 'logical replication apply worker for subscription "regress_sub" two_phase is ENABLED', $log_offset);
+
+# And do COMMIT PREPARED the prepared transaction
+$node_publisher->safe_psql('postgres',
+ "COMMIT PREPARED 'test_prepared_tab_full';");
+$node_publisher->wait_for_catchup('regress_sub');
+
+# Verify inserted tuples are replicated
+$result = $node_subscriber->safe_psql('postgres',
+ "SELECT count(*) FROM tab_full;");
+is($result, q(5),
+ "prepared transactions done before altering can be replicated");
+
+done_testing();
--
2.43.0
[application/octet-stream] v10-0003-Abort-prepared-transactions-while-altering-two_p.patch (9.6K, ../../OSBPR01MB2552F66463EFCFD654E87C09F5E32@OSBPR01MB2552.jpnprd01.prod.outlook.com/4-v10-0003-Abort-prepared-transactions-while-altering-two_p.patch)
download | inline diff:
From d8c07a0bd72ffa32c8e2a553254d79bdc3fac9db Mon Sep 17 00:00:00 2001
From: Hayato Kuroda <[email protected]>
Date: Mon, 8 Apr 2024 12:39:12 +0000
Subject: [PATCH v10 3/4] Abort prepared transactions while altering two_phase
to off
If we alter the two_phase parameter from "on" to "off" and there are prepared
transactions on the subscriber, they won't be resolved. To avoid this issue, we
allow the backend to abort all prepared transactions while altering the
subscription.
---
doc/src/sgml/ref/alter_subscription.sgml | 11 ++-
src/backend/access/transam/twophase.c | 17 ++---
src/backend/commands/subscriptioncmds.c | 69 +++++++++++--------
src/include/access/twophase.h | 3 +-
src/test/subscription/t/099_twophase_added.pl | 45 ++++++++++++
5 files changed, 104 insertions(+), 41 deletions(-)
diff --git a/doc/src/sgml/ref/alter_subscription.sgml b/doc/src/sgml/ref/alter_subscription.sgml
index 0c2894a94e..2c6502275a 100644
--- a/doc/src/sgml/ref/alter_subscription.sgml
+++ b/doc/src/sgml/ref/alter_subscription.sgml
@@ -233,8 +233,6 @@ ALTER SUBSCRIPTION <replaceable class="parameter">name</replaceable> RENAME TO <
<link linkend="sql-createsubscription-params-with-failover"><literal>failover</literal></link>, and
<link linkend="sql-createsubscription-params-with-two-phase"><literal>two_phase</literal></link>.
Only a superuser can set <literal>password_required = false</literal>.
- The <literal>two_phase</literal> parameter can only be altered when the
- subscription is disabled.
</para>
<para>
@@ -256,6 +254,15 @@ ALTER SUBSCRIPTION <replaceable class="parameter">name</replaceable> RENAME TO <
<link linkend="sql-createsubscription-params-with-failover"><literal>failover</literal></link>
option is enabled.
</para>
+
+ <para>
+ The <literal>two_phase</literal> parameter can only be altered when the
+ subscription is disabled. When altering the parameter from <literal>true</literal>
+ to <literal>false</literal>, the backend process checks for any incomplete
+ prepared transactions done by the logical replication worker (from when
+ <literal>two_phase</literal> parameter was still <literal>true</literal>)
+ and, if any are found, those are aborted.
+ </para>
</listitem>
</varlistentry>
diff --git a/src/backend/access/transam/twophase.c b/src/backend/access/transam/twophase.c
index 66fa591eb5..f384bd8c0a 100644
--- a/src/backend/access/transam/twophase.c
+++ b/src/backend/access/transam/twophase.c
@@ -2720,13 +2720,13 @@ IsTwoPhaseTransactionGidForSubid(Oid subid, char *gid)
}
/*
- * LookupGXactBySubid
- * Check if the prepared transaction done by apply worker exists.
+ * GetGidListBySubid
+ * Get a list of GIDs which is PREPARE'd by the given subscription.
*/
-bool
-LookupGXactBySubid(Oid subid)
+List *
+GetGidListBySubid(Oid subid)
{
- bool found = false;
+ List *list = NIL;
LWLockAcquire(TwoPhaseStateLock, LW_SHARED);
for (int i = 0; i < TwoPhaseState->numPrepXacts; i++)
@@ -2736,11 +2736,8 @@ LookupGXactBySubid(Oid subid)
/* Ignore not-yet-valid GIDs. */
if (gxact->valid &&
IsTwoPhaseTransactionGidForSubid(subid, gxact->gid))
- {
- found = true;
- break;
- }
+ list = lappend(list, pstrdup(gxact->gid));
}
LWLockRelease(TwoPhaseStateLock);
- return found;
+ return list;
}
diff --git a/src/backend/commands/subscriptioncmds.c b/src/backend/commands/subscriptioncmds.c
index d9abf687d1..c0e5d1af45 100644
--- a/src/backend/commands/subscriptioncmds.c
+++ b/src/backend/commands/subscriptioncmds.c
@@ -1176,36 +1176,49 @@ AlterSubscription(ParseState *pstate, AlterSubscriptionStmt *stmt,
logicalrep_workers_stop(subid);
/*
- * two_phase cannot be disabled if there are any
- * uncommitted prepared transactions present.
- */
- if (!opts.twophase &&
- form->subtwophasestate == LOGICALREP_TWOPHASE_STATE_ENABLED &&
- LookupGXactBySubid(subid))
- ereport(ERROR,
- (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
- errmsg("cannot disable two_phase when uncommitted prepared transactions present"),
- errhint("Resolve these transactions and try again")));
-
- /*
- * Altering the parameter from "true" to "false" within a
- * transaction is prohibited. Since the apply worker does
- * not alter the slot option to false, the backend must
- * connect to the publisher and expressly change the
- * parameter.
- *
- * There is no need to do something remarkable regarding
- * the "false" to "true" case; the backend process alters
- * subtwophase to LOGICALREP_TWOPHASE_STATE_PENDING once.
- * After the subscription is enabled, a new logical
- * replication worker requests to change the two_phase
- * option of its slot when the initial data synchronization
- * is done. The code path is the same as the case in which
- * two_phase is initially set to true.
+ * If two_phase was enabled, there is a possibility that
+ * transactions have already been PREPARE'd. They must be
+ * checked and rolled back.
*/
if (!opts.twophase)
- PreventInTransactionBlock(isTopLevel,
- "ALTER SUBSCRIPTION ... SET (two_phase = false)");
+ {
+ List *prepared_xacts;
+
+ /*
+ * Altering the parameter from "true" to "false" within
+ * a transaction is prohibited. Since the apply worker
+ * does not alter the slot option to false, the backend
+ * must connect to the publisher and expressly change
+ * the parameter.
+ *
+ * There is no need to do something remarkable
+ * regarding the "false" to "true" case; the backend
+ * process alters subtwophase to
+ * LOGICALREP_TWOPHASE_STATE_PENDING once. After the
+ * subscription is enabled, a new logical replication
+ * worker requests to change the two_phase option of
+ * its slot when the initial data synchronization is
+ * done. The code path is the same as the case in which
+ * two_phase is initially set to true.
+ */
+ if (!opts.twophase)
+ PreventInTransactionBlock(isTopLevel,
+ "ALTER SUBSCRIPTION ... SET (two_phase = false)");
+
+ /*
+ * To prevent prepared transactions from being
+ * isolated, they must manually be aborted.
+ */
+ if (sub->twophasestate == LOGICALREP_TWOPHASE_STATE_ENABLED &&
+ (prepared_xacts = GetGidListBySubid(subid)) != NIL)
+ {
+ /* Abort all listed transactions */
+ foreach_ptr(char, gid, prepared_xacts)
+ FinishPreparedTransaction(gid, false);
+
+ list_free_deep(prepared_xacts);
+ }
+ }
/* Change system catalog acoordingly */
values[Anum_pg_subscription_subtwophasestate - 1] =
diff --git a/src/include/access/twophase.h b/src/include/access/twophase.h
index d37e06fdee..f7a5cf0c12 100644
--- a/src/include/access/twophase.h
+++ b/src/include/access/twophase.h
@@ -18,6 +18,7 @@
#include "access/xlogdefs.h"
#include "datatype/timestamp.h"
#include "storage/lock.h"
+#include "nodes/pg_list.h"
/*
* GlobalTransactionData is defined in twophase.c; other places have no
@@ -65,6 +66,6 @@ extern bool LookupGXact(const char *gid, XLogRecPtr prepare_end_lsn,
extern void TwoPhaseTransactionGid(Oid subid, TransactionId xid, char *gid,
int szgid);
-extern bool LookupGXactBySubid(Oid subid);
+extern List *GetGidListBySubid(Oid subid);
#endif /* TWOPHASE_H */
diff --git a/src/test/subscription/t/099_twophase_added.pl b/src/test/subscription/t/099_twophase_added.pl
index b7c97f8454..7abe1c37d5 100644
--- a/src/test/subscription/t/099_twophase_added.pl
+++ b/src/test/subscription/t/099_twophase_added.pl
@@ -93,4 +93,49 @@ $result = $node_subscriber->safe_psql('postgres',
is($result, q(5),
"prepared transactions done before altering can be replicated");
+#####################
+# Check the case that prepared transactions exist on the subscriber node
+#
+# If the two_phase is altering from "on" to "off" and there are prepared
+# transactions on the subscriber, they must be aborted. This test checks it.
+
+# Prepare a transaction to insert some tuples into the table
+$node_publisher->safe_psql(
+ 'postgres', "
+ BEGIN;
+ INSERT INTO tab_full VALUES (generate_series(6, 10));
+ PREPARE TRANSACTION 'test_prepared_tab_full';");
+
+$node_publisher->wait_for_catchup('regress_sub');
+
+# Verify the prepared transaction has been replicated to the subscriber because
+# two_phase is set to "on".
+$result = $node_subscriber->safe_psql('postgres',
+ "SELECT count(*) FROM pg_prepared_xacts;");
+is($result, q(1), "transaction has been prepared on subscriber");
+
+# Toggle the two_phase to "off" before the COMMIT PREPARED
+$node_subscriber->safe_psql(
+ 'postgres', "
+ ALTER SUBSCRIPTION regress_sub DISABLE;
+ ALTER SUBSCRIPTION regress_sub SET (two_phase = off);
+ ALTER SUBSCRIPTION regress_sub ENABLE;");
+
+# Verify any prepared transactions are aborted because two_phase is changed to
+# "off".
+$result = $node_subscriber->safe_psql('postgres',
+ "SELECT count(*) FROM pg_prepared_xacts;");
+is($result, q(0), "prepared transaction done by worker is aborted");
+
+# Do COMMIT PREPARED the prepared transaction
+$node_publisher->safe_psql( 'postgres',
+ "COMMIT PREPARED 'test_prepared_tab_full';");
+$node_publisher->wait_for_catchup('regress_sub');
+
+# Verify inserted tuples are replicated
+$result = $node_subscriber->safe_psql('postgres',
+ "SELECT count(10) FROM tab_full;");
+is($result, q(10),
+ "prepared transactions on publisher can be replicated");
+
done_testing();
--
2.43.0
[application/octet-stream] v10-0004-Add-force_alter-option-for-ALTER-SUBSCRIPTION-.-.patch (57.3K, ../../OSBPR01MB2552F66463EFCFD654E87C09F5E32@OSBPR01MB2552.jpnprd01.prod.outlook.com/5-v10-0004-Add-force_alter-option-for-ALTER-SUBSCRIPTION-.-.patch)
download | inline diff:
From f2855efa1ccb7dfba197df652d9147b52c8a8270 Mon Sep 17 00:00:00 2001
From: Hayato Kuroda <[email protected]>
Date: Fri, 19 Apr 2024 11:03:19 +0000
Subject: [PATCH v10 4/4] Add force_alter option for ALTER SUBSCRIPTION ... SET
command
Previously, all prepared transactions on the standby were rolled back when
toggling two_phase from "true" to "false". However, this operation may not be
expected by users. To ensure users understand what happens, we added the
"force_alter" parameter. When two_phase is toggling to "false", and there are
prepared transactions, they will be aborted only when "force_alter" is set to
true. Otherwise, an ERROR occurs.
---
doc/src/sgml/catalogs.sgml | 12 ++
doc/src/sgml/ref/alter_subscription.sgml | 16 +-
doc/src/sgml/ref/create_subscription.sgml | 20 +++
src/backend/catalog/pg_subscription.c | 1 +
src/backend/catalog/system_views.sql | 2 +-
src/backend/commands/subscriptioncmds.c | 36 ++++-
src/bin/pg_dump/pg_dump.c | 14 ++
src/bin/pg_dump/pg_dump.h | 1 +
src/bin/psql/describe.c | 7 +-
src/include/catalog/pg_subscription.h | 13 ++
src/test/regress/expected/subscription.out | 152 +++++++++---------
src/test/subscription/t/099_twophase_added.pl | 43 +++--
12 files changed, 221 insertions(+), 96 deletions(-)
diff --git a/doc/src/sgml/catalogs.sgml b/doc/src/sgml/catalogs.sgml
index 5a6f65025b..124982b0a2 100644
--- a/doc/src/sgml/catalogs.sgml
+++ b/doc/src/sgml/catalogs.sgml
@@ -8049,6 +8049,18 @@ SCRAM-SHA-256$<replaceable><iteration count></replaceable>:<replaceable>&l
</para></entry>
</row>
+ <row>
+ <entry role="catalog_table_entry"><para role="column_definition">
+ <structfield>subforcealter</structfield> <type>bool</type>
+ </para>
+ <para>
+ If true, then the <link linkend="sql-altersubscription"><command>ALTER SUBSCRIPTION</command>
+ can disable <literal>two_phase</literal> option, even if there are
+ uncommitted prepared transactions from when <literal>two_phase</literal>
+ was enabled
+ </para></entry>
+ </row>
+
<row>
<entry role="catalog_table_entry"><para role="column_definition">
<structfield>subconninfo</structfield> <type>text</type>
diff --git a/doc/src/sgml/ref/alter_subscription.sgml b/doc/src/sgml/ref/alter_subscription.sgml
index 2c6502275a..e462d8c4d2 100644
--- a/doc/src/sgml/ref/alter_subscription.sgml
+++ b/doc/src/sgml/ref/alter_subscription.sgml
@@ -230,8 +230,9 @@ ALTER SUBSCRIPTION <replaceable class="parameter">name</replaceable> RENAME TO <
<link linkend="sql-createsubscription-params-with-password-required"><literal>password_required</literal></link>,
<link linkend="sql-createsubscription-params-with-run-as-owner"><literal>run_as_owner</literal></link>,
<link linkend="sql-createsubscription-params-with-origin"><literal>origin</literal></link>,
- <link linkend="sql-createsubscription-params-with-failover"><literal>failover</literal></link>, and
- <link linkend="sql-createsubscription-params-with-two-phase"><literal>two_phase</literal></link>.
+ <link linkend="sql-createsubscription-params-with-failover"><literal>failover</literal></link>,
+ <link linkend="sql-createsubscription-params-with-two-phase"><literal>two_phase</literal></link>, and
+ <link linkend="sql-createsubscription-params-with-force-alter"><literal>force_alter</literal></link>
Only a superuser can set <literal>password_required = false</literal>.
</para>
@@ -257,11 +258,12 @@ ALTER SUBSCRIPTION <replaceable class="parameter">name</replaceable> RENAME TO <
<para>
The <literal>two_phase</literal> parameter can only be altered when the
- subscription is disabled. When altering the parameter from <literal>true</literal>
- to <literal>false</literal>, the backend process checks for any incomplete
- prepared transactions done by the logical replication worker (from when
- <literal>two_phase</literal> parameter was still <literal>true</literal>)
- and, if any are found, those are aborted.
+ subscription is disabled. Altering the parameter from <literal>true</literal>
+ to <literal>false</literal> will give an error when when there are
+ prepared transactions done by the logical replication worker. If you want
+ to alter the parameter forcibly in this case,
+ <link linkend="sql-createsubscription-params-with-force-alter"><literal>force_alter</literal></link>
+ option must be set to <literal>true</literal> at the same time.
</para>
</listitem>
</varlistentry>
diff --git a/doc/src/sgml/ref/create_subscription.sgml b/doc/src/sgml/ref/create_subscription.sgml
index 740b7d9421..e8ef965c81 100644
--- a/doc/src/sgml/ref/create_subscription.sgml
+++ b/doc/src/sgml/ref/create_subscription.sgml
@@ -428,6 +428,26 @@ CREATE SUBSCRIPTION <replaceable class="parameter">subscription_name</replaceabl
</para>
</listitem>
</varlistentry>
+
+ <varlistentry id="sql-createsubscription-params-with-force-alter">
+ <term><literal>force_alter</literal> (<type>boolean</type>)</term>
+ <listitem>
+ <para>
+ Specifies if the <link linkend="sql-altersubscription"><command>ALTER SUBSCRIPTION</command>
+ can be forced to proceed instead of giving an error. There is
+ currently only one scenario where this parameter has any effect: When
+ altering <literal>two_phase</literal> option from <literal>true</literal>
+ to <literal>false</literal> it is possible for there to be incomplete
+ prepared transactions done by the logical replication worker (from
+ when <literal>two_phase</literal> parameter was still <literal>true</literal>).
+ If <literal>force_alter</literal> is <literal>false</literal>, then
+ this will give an error; if <literal>force_alter</literal> is
+ <literal>true</literal>, then the incomplete prepared transactions
+ are aborted and the alter will proceed.
+ The default is <literal>false</literal>.
+ </para>
+ </listitem>
+ </varlistentry>
</variablelist></para>
</listitem>
diff --git a/src/backend/catalog/pg_subscription.c b/src/backend/catalog/pg_subscription.c
index 9efc9159f2..b568fe3470 100644
--- a/src/backend/catalog/pg_subscription.c
+++ b/src/backend/catalog/pg_subscription.c
@@ -72,6 +72,7 @@ GetSubscription(Oid subid, bool missing_ok)
sub->passwordrequired = subform->subpasswordrequired;
sub->runasowner = subform->subrunasowner;
sub->failover = subform->subfailover;
+ sub->forcealter = subform->subforcealter;
/* Get conninfo */
datum = SysCacheGetAttrNotNull(SUBSCRIPTIONOID,
diff --git a/src/backend/catalog/system_views.sql b/src/backend/catalog/system_views.sql
index 53047cab5f..de3d3d8f3e 100644
--- a/src/backend/catalog/system_views.sql
+++ b/src/backend/catalog/system_views.sql
@@ -1358,7 +1358,7 @@ REVOKE ALL ON pg_replication_origin_status FROM public;
REVOKE ALL ON pg_subscription FROM public;
GRANT SELECT (oid, subdbid, subskiplsn, subname, subowner, subenabled,
subbinary, substream, subtwophasestate, subdisableonerr,
- subpasswordrequired, subrunasowner, subfailover,
+ subpasswordrequired, subrunasowner, subfailover, subforcealter,
subslotname, subsynccommit, subpublications, suborigin)
ON pg_subscription TO public;
diff --git a/src/backend/commands/subscriptioncmds.c b/src/backend/commands/subscriptioncmds.c
index c0e5d1af45..32d00d2c2a 100644
--- a/src/backend/commands/subscriptioncmds.c
+++ b/src/backend/commands/subscriptioncmds.c
@@ -73,6 +73,7 @@
#define SUBOPT_FAILOVER 0x00002000
#define SUBOPT_LSN 0x00004000
#define SUBOPT_ORIGIN 0x00008000
+#define SUBOPT_FORCE_ALTER 0x00010000
/* check if the 'val' has 'bits' set */
#define IsSet(val, bits) (((val) & (bits)) == (bits))
@@ -100,6 +101,7 @@ typedef struct SubOpts
bool failover;
char *origin;
XLogRecPtr lsn;
+ bool force_alter;
} SubOpts;
static List *fetch_table_list(WalReceiverConn *wrconn, List *publications);
@@ -162,6 +164,8 @@ parse_subscription_options(ParseState *pstate, List *stmt_options,
opts->failover = false;
if (IsSet(supported_opts, SUBOPT_ORIGIN))
opts->origin = pstrdup(LOGICALREP_ORIGIN_ANY);
+ if (IsSet(supported_opts, SUBOPT_FORCE_ALTER))
+ opts->force_alter = false;
/* Parse options */
foreach(lc, stmt_options)
@@ -367,6 +371,15 @@ parse_subscription_options(ParseState *pstate, List *stmt_options,
opts->specified_opts |= SUBOPT_LSN;
opts->lsn = lsn;
}
+ else if (IsSet(supported_opts, SUBOPT_FORCE_ALTER) &&
+ strcmp(defel->defname, "force_alter") == 0)
+ {
+ if (IsSet(opts->specified_opts, SUBOPT_FORCE_ALTER))
+ errorConflictingDefElem(defel, pstate);
+
+ opts->specified_opts |= SUBOPT_FORCE_ALTER;
+ opts->force_alter = defGetBoolean(defel);
+ }
else
ereport(ERROR,
(errcode(ERRCODE_SYNTAX_ERROR),
@@ -604,7 +617,8 @@ CreateSubscription(ParseState *pstate, CreateSubscriptionStmt *stmt,
SUBOPT_SYNCHRONOUS_COMMIT | SUBOPT_BINARY |
SUBOPT_STREAMING | SUBOPT_TWOPHASE_COMMIT |
SUBOPT_DISABLE_ON_ERR | SUBOPT_PASSWORD_REQUIRED |
- SUBOPT_RUN_AS_OWNER | SUBOPT_FAILOVER | SUBOPT_ORIGIN);
+ SUBOPT_RUN_AS_OWNER | SUBOPT_FAILOVER | SUBOPT_ORIGIN |
+ SUBOPT_FORCE_ALTER);
parse_subscription_options(pstate, stmt->options, supported_opts, &opts);
/*
@@ -711,6 +725,7 @@ CreateSubscription(ParseState *pstate, CreateSubscriptionStmt *stmt,
values[Anum_pg_subscription_subpasswordrequired - 1] = BoolGetDatum(opts.passwordrequired);
values[Anum_pg_subscription_subrunasowner - 1] = BoolGetDatum(opts.runasowner);
values[Anum_pg_subscription_subfailover - 1] = BoolGetDatum(opts.failover);
+ values[Anum_pg_subscription_subforcealter - 1] = BoolGetDatum(opts.force_alter);
values[Anum_pg_subscription_subconninfo - 1] =
CStringGetTextDatum(conninfo);
if (opts.slot_name)
@@ -1150,7 +1165,7 @@ AlterSubscription(ParseState *pstate, AlterSubscriptionStmt *stmt,
SUBOPT_DISABLE_ON_ERR |
SUBOPT_PASSWORD_REQUIRED |
SUBOPT_RUN_AS_OWNER | SUBOPT_FAILOVER |
- SUBOPT_ORIGIN);
+ SUBOPT_ORIGIN | SUBOPT_FORCE_ALTER);
parse_subscription_options(pstate, stmt->options,
supported_opts, &opts);
@@ -1212,6 +1227,23 @@ AlterSubscription(ParseState *pstate, AlterSubscriptionStmt *stmt,
if (sub->twophasestate == LOGICALREP_TWOPHASE_STATE_ENABLED &&
(prepared_xacts = GetGidListBySubid(subid)) != NIL)
{
+ bool raise_error =
+ IsSet(opts.specified_opts, SUBOPT_FORCE_ALTER) ?
+ !opts.force_alter : !sub->forcealter;
+
+ /*
+ * Abort prepared transactions only if
+ * 'force_alter' option is true. Otherwise raise
+ * an ERROR.
+ */
+ if (raise_error)
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("cannot alter %s when there are prepared transactions",
+ "two_phase = false"),
+ errhint("Resolve these transactions or set %s, and then try again.",
+ "force_alter = true")));
+
/* Abort all listed transactions */
foreach_ptr(char, gid, prepared_xacts)
FinishPreparedTransaction(gid, false);
diff --git a/src/bin/pg_dump/pg_dump.c b/src/bin/pg_dump/pg_dump.c
index ac920f64c7..b4b0c9e583 100644
--- a/src/bin/pg_dump/pg_dump.c
+++ b/src/bin/pg_dump/pg_dump.c
@@ -4739,6 +4739,7 @@ getSubscriptions(Archive *fout)
int i_suboriginremotelsn;
int i_subenabled;
int i_subfailover;
+ int i_subforcealter;
int i,
ntups;
@@ -4816,6 +4817,13 @@ getSubscriptions(Archive *fout)
appendPQExpBuffer(query,
" false AS subfailover\n");
+ if (fout->remoteVersion >= 170000)
+ appendPQExpBufferStr(query,
+ " s.subforcealter\n");
+ else
+ appendPQExpBuffer(query,
+ " false AS subforcealter\n");
+
appendPQExpBufferStr(query,
"FROM pg_subscription s\n");
@@ -4854,6 +4862,7 @@ getSubscriptions(Archive *fout)
i_suboriginremotelsn = PQfnumber(res, "suboriginremotelsn");
i_subenabled = PQfnumber(res, "subenabled");
i_subfailover = PQfnumber(res, "subfailover");
+ i_subforcealter = PQfnumber(res, "subforcealter");
subinfo = pg_malloc(ntups * sizeof(SubscriptionInfo));
@@ -4900,6 +4909,8 @@ getSubscriptions(Archive *fout)
pg_strdup(PQgetvalue(res, i, i_subenabled));
subinfo[i].subfailover =
pg_strdup(PQgetvalue(res, i, i_subfailover));
+ subinfo[i].subforcealter =
+ pg_strdup(PQgetvalue(res, i, i_subforcealter));
/* Decide whether we want to dump it */
selectDumpableObject(&(subinfo[i].dobj), fout);
@@ -5140,6 +5151,9 @@ dumpSubscription(Archive *fout, const SubscriptionInfo *subinfo)
if (strcmp(subinfo->subfailover, "t") == 0)
appendPQExpBufferStr(query, ", failover = true");
+ if (strcmp(subinfo->subforcealter, "t") == 0)
+ appendPQExpBufferStr(query, ", force_alter = true");
+
if (strcmp(subinfo->subsynccommit, "off") != 0)
appendPQExpBuffer(query, ", synchronous_commit = %s", fmtId(subinfo->subsynccommit));
diff --git a/src/bin/pg_dump/pg_dump.h b/src/bin/pg_dump/pg_dump.h
index f518a1e6d2..c666b9c113 100644
--- a/src/bin/pg_dump/pg_dump.h
+++ b/src/bin/pg_dump/pg_dump.h
@@ -672,6 +672,7 @@ typedef struct _SubscriptionInfo
char *suborigin;
char *suboriginremotelsn;
char *subfailover;
+ char *subforcealter;
} SubscriptionInfo;
/*
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index 3af44acef1..8e0a0b3b36 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -6537,7 +6537,7 @@ describeSubscriptions(const char *pattern, bool verbose)
printQueryOpt myopt = pset.popt;
static const bool translate_columns[] = {false, false, false, false,
false, false, false, false, false, false, false, false, false, false,
- false};
+ false, false};
if (pset.sversion < 100000)
{
@@ -6606,6 +6606,11 @@ describeSubscriptions(const char *pattern, bool verbose)
", subfailover AS \"%s\"\n",
gettext_noop("Failover"));
+ if (pset.sversion >= 170000)
+ appendPQExpBuffer(&buf,
+ ", subforcealter AS \"%s\"\n",
+ gettext_noop("Force alter"));
+
appendPQExpBuffer(&buf,
", subsynccommit AS \"%s\"\n"
", subconninfo AS \"%s\"\n",
diff --git a/src/include/catalog/pg_subscription.h b/src/include/catalog/pg_subscription.h
index 0aa14ec4a2..c23de43d79 100644
--- a/src/include/catalog/pg_subscription.h
+++ b/src/include/catalog/pg_subscription.h
@@ -98,6 +98,13 @@ CATALOG(pg_subscription,6100,SubscriptionRelationId) BKI_SHARED_RELATION BKI_ROW
* slots) in the upstream database are enabled
* to be synchronized to the standbys. */
+ bool subforcealter; /* True allows the ALTER SUBSCRIPTION command
+ * to proceed under conditions that would
+ * otherwise result in an error. Currently,
+ * 'force_alter' only has an effect when
+ * altering the two_phase option from "true" to
+ * "false". */
+
#ifdef CATALOG_VARLEN /* variable-length fields start here */
/* Connection string to the publisher */
text subconninfo BKI_FORCE_NOT_NULL;
@@ -151,6 +158,12 @@ typedef struct Subscription
* (i.e. the main slot and the table sync
* slots) in the upstream database are enabled
* to be synchronized to the standbys. */
+ bool forcealter; /* True allows the ALTER SUBSCRIPTION command
+ * to proceed under conditions that would
+ * otherwise result in an error. Currently,
+ * 'force_alter' only has an effect when
+ * altering the two_phase option from "true" to
+ * "false". */
char *conninfo; /* Connection string to the publisher */
char *slotname; /* Name of the replication slot */
char *synccommit; /* Synchronous commit setting for worker */
diff --git a/src/test/regress/expected/subscription.out b/src/test/regress/expected/subscription.out
index 51fa4b9690..b36fc6b8f7 100644
--- a/src/test/regress/expected/subscription.out
+++ b/src/test/regress/expected/subscription.out
@@ -116,18 +116,18 @@ CREATE SUBSCRIPTION regress_testsub4 CONNECTION 'dbname=regress_doesnotexist' PU
WARNING: subscription was created, but is not connected
HINT: To initiate replication, you must manually create the replication slot, enable the subscription, and refresh the subscription.
\dRs+ regress_testsub4
- List of subscriptions
- Name | Owner | Enabled | Publication | Binary | Streaming | Two-phase commit | Disable on error | Origin | Password required | Run as owner? | Failover | Synchronous commit | Conninfo | Skip LSN
-------------------+---------------------------+---------+-------------+--------+-----------+------------------+------------------+--------+-------------------+---------------+----------+--------------------+-----------------------------+----------
- regress_testsub4 | regress_subscription_user | f | {testpub} | f | off | d | f | none | t | f | f | off | dbname=regress_doesnotexist | 0/0
+ List of subscriptions
+ Name | Owner | Enabled | Publication | Binary | Streaming | Two-phase commit | Disable on error | Origin | Password required | Run as owner? | Failover | Force alter | Synchronous commit | Conninfo | Skip LSN
+------------------+---------------------------+---------+-------------+--------+-----------+------------------+------------------+--------+-------------------+---------------+----------+-------------+--------------------+-----------------------------+----------
+ regress_testsub4 | regress_subscription_user | f | {testpub} | f | off | d | f | none | t | f | f | f | off | dbname=regress_doesnotexist | 0/0
(1 row)
ALTER SUBSCRIPTION regress_testsub4 SET (origin = any);
\dRs+ regress_testsub4
- List of subscriptions
- Name | Owner | Enabled | Publication | Binary | Streaming | Two-phase commit | Disable on error | Origin | Password required | Run as owner? | Failover | Synchronous commit | Conninfo | Skip LSN
-------------------+---------------------------+---------+-------------+--------+-----------+------------------+------------------+--------+-------------------+---------------+----------+--------------------+-----------------------------+----------
- regress_testsub4 | regress_subscription_user | f | {testpub} | f | off | d | f | any | t | f | f | off | dbname=regress_doesnotexist | 0/0
+ List of subscriptions
+ Name | Owner | Enabled | Publication | Binary | Streaming | Two-phase commit | Disable on error | Origin | Password required | Run as owner? | Failover | Force alter | Synchronous commit | Conninfo | Skip LSN
+------------------+---------------------------+---------+-------------+--------+-----------+------------------+------------------+--------+-------------------+---------------+----------+-------------+--------------------+-----------------------------+----------
+ regress_testsub4 | regress_subscription_user | f | {testpub} | f | off | d | f | any | t | f | f | f | off | dbname=regress_doesnotexist | 0/0
(1 row)
DROP SUBSCRIPTION regress_testsub3;
@@ -145,10 +145,10 @@ ALTER SUBSCRIPTION regress_testsub CONNECTION 'foobar';
ERROR: invalid connection string syntax: missing "=" after "foobar" in connection info string
\dRs+
- List of subscriptions
- Name | Owner | Enabled | Publication | Binary | Streaming | Two-phase commit | Disable on error | Origin | Password required | Run as owner? | Failover | Synchronous commit | Conninfo | Skip LSN
------------------+---------------------------+---------+-------------+--------+-----------+------------------+------------------+--------+-------------------+---------------+----------+--------------------+-----------------------------+----------
- regress_testsub | regress_subscription_user | f | {testpub} | f | off | d | f | any | t | f | f | off | dbname=regress_doesnotexist | 0/0
+ List of subscriptions
+ Name | Owner | Enabled | Publication | Binary | Streaming | Two-phase commit | Disable on error | Origin | Password required | Run as owner? | Failover | Force alter | Synchronous commit | Conninfo | Skip LSN
+-----------------+---------------------------+---------+-------------+--------+-----------+------------------+------------------+--------+-------------------+---------------+----------+-------------+--------------------+-----------------------------+----------
+ regress_testsub | regress_subscription_user | f | {testpub} | f | off | d | f | any | t | f | f | f | off | dbname=regress_doesnotexist | 0/0
(1 row)
ALTER SUBSCRIPTION regress_testsub SET PUBLICATION testpub2, testpub3 WITH (refresh = false);
@@ -157,10 +157,10 @@ ALTER SUBSCRIPTION regress_testsub SET (slot_name = 'newname');
ALTER SUBSCRIPTION regress_testsub SET (password_required = false);
ALTER SUBSCRIPTION regress_testsub SET (run_as_owner = true);
\dRs+
- List of subscriptions
- Name | Owner | Enabled | Publication | Binary | Streaming | Two-phase commit | Disable on error | Origin | Password required | Run as owner? | Failover | Synchronous commit | Conninfo | Skip LSN
------------------+---------------------------+---------+---------------------+--------+-----------+------------------+------------------+--------+-------------------+---------------+----------+--------------------+------------------------------+----------
- regress_testsub | regress_subscription_user | f | {testpub2,testpub3} | f | off | d | f | any | f | t | f | off | dbname=regress_doesnotexist2 | 0/0
+ List of subscriptions
+ Name | Owner | Enabled | Publication | Binary | Streaming | Two-phase commit | Disable on error | Origin | Password required | Run as owner? | Failover | Force alter | Synchronous commit | Conninfo | Skip LSN
+-----------------+---------------------------+---------+---------------------+--------+-----------+------------------+------------------+--------+-------------------+---------------+----------+-------------+--------------------+------------------------------+----------
+ regress_testsub | regress_subscription_user | f | {testpub2,testpub3} | f | off | d | f | any | f | t | f | f | off | dbname=regress_doesnotexist2 | 0/0
(1 row)
ALTER SUBSCRIPTION regress_testsub SET (password_required = true);
@@ -176,10 +176,10 @@ ERROR: unrecognized subscription parameter: "create_slot"
-- ok
ALTER SUBSCRIPTION regress_testsub SKIP (lsn = '0/12345');
\dRs+
- List of subscriptions
- Name | Owner | Enabled | Publication | Binary | Streaming | Two-phase commit | Disable on error | Origin | Password required | Run as owner? | Failover | Synchronous commit | Conninfo | Skip LSN
------------------+---------------------------+---------+---------------------+--------+-----------+------------------+------------------+--------+-------------------+---------------+----------+--------------------+------------------------------+----------
- regress_testsub | regress_subscription_user | f | {testpub2,testpub3} | f | off | d | f | any | t | f | f | off | dbname=regress_doesnotexist2 | 0/12345
+ List of subscriptions
+ Name | Owner | Enabled | Publication | Binary | Streaming | Two-phase commit | Disable on error | Origin | Password required | Run as owner? | Failover | Force alter | Synchronous commit | Conninfo | Skip LSN
+-----------------+---------------------------+---------+---------------------+--------+-----------+------------------+------------------+--------+-------------------+---------------+----------+-------------+--------------------+------------------------------+----------
+ regress_testsub | regress_subscription_user | f | {testpub2,testpub3} | f | off | d | f | any | t | f | f | f | off | dbname=regress_doesnotexist2 | 0/12345
(1 row)
-- ok - with lsn = NONE
@@ -188,10 +188,10 @@ ALTER SUBSCRIPTION regress_testsub SKIP (lsn = NONE);
ALTER SUBSCRIPTION regress_testsub SKIP (lsn = '0/0');
ERROR: invalid WAL location (LSN): 0/0
\dRs+
- List of subscriptions
- Name | Owner | Enabled | Publication | Binary | Streaming | Two-phase commit | Disable on error | Origin | Password required | Run as owner? | Failover | Synchronous commit | Conninfo | Skip LSN
------------------+---------------------------+---------+---------------------+--------+-----------+------------------+------------------+--------+-------------------+---------------+----------+--------------------+------------------------------+----------
- regress_testsub | regress_subscription_user | f | {testpub2,testpub3} | f | off | d | f | any | t | f | f | off | dbname=regress_doesnotexist2 | 0/0
+ List of subscriptions
+ Name | Owner | Enabled | Publication | Binary | Streaming | Two-phase commit | Disable on error | Origin | Password required | Run as owner? | Failover | Force alter | Synchronous commit | Conninfo | Skip LSN
+-----------------+---------------------------+---------+---------------------+--------+-----------+------------------+------------------+--------+-------------------+---------------+----------+-------------+--------------------+------------------------------+----------
+ regress_testsub | regress_subscription_user | f | {testpub2,testpub3} | f | off | d | f | any | t | f | f | f | off | dbname=regress_doesnotexist2 | 0/0
(1 row)
BEGIN;
@@ -223,10 +223,10 @@ ALTER SUBSCRIPTION regress_testsub_foo SET (synchronous_commit = foobar);
ERROR: invalid value for parameter "synchronous_commit": "foobar"
HINT: Available values: local, remote_write, remote_apply, on, off.
\dRs+
- List of subscriptions
- Name | Owner | Enabled | Publication | Binary | Streaming | Two-phase commit | Disable on error | Origin | Password required | Run as owner? | Failover | Synchronous commit | Conninfo | Skip LSN
----------------------+---------------------------+---------+---------------------+--------+-----------+------------------+------------------+--------+-------------------+---------------+----------+--------------------+------------------------------+----------
- regress_testsub_foo | regress_subscription_user | f | {testpub2,testpub3} | f | off | d | f | any | t | f | f | local | dbname=regress_doesnotexist2 | 0/0
+ List of subscriptions
+ Name | Owner | Enabled | Publication | Binary | Streaming | Two-phase commit | Disable on error | Origin | Password required | Run as owner? | Failover | Force alter | Synchronous commit | Conninfo | Skip LSN
+---------------------+---------------------------+---------+---------------------+--------+-----------+------------------+------------------+--------+-------------------+---------------+----------+-------------+--------------------+------------------------------+----------
+ regress_testsub_foo | regress_subscription_user | f | {testpub2,testpub3} | f | off | d | f | any | t | f | f | f | local | dbname=regress_doesnotexist2 | 0/0
(1 row)
-- rename back to keep the rest simple
@@ -255,19 +255,19 @@ CREATE SUBSCRIPTION regress_testsub CONNECTION 'dbname=regress_doesnotexist' PUB
WARNING: subscription was created, but is not connected
HINT: To initiate replication, you must manually create the replication slot, enable the subscription, and refresh the subscription.
\dRs+
- List of subscriptions
- Name | Owner | Enabled | Publication | Binary | Streaming | Two-phase commit | Disable on error | Origin | Password required | Run as owner? | Failover | Synchronous commit | Conninfo | Skip LSN
------------------+---------------------------+---------+-------------+--------+-----------+------------------+------------------+--------+-------------------+---------------+----------+--------------------+-----------------------------+----------
- regress_testsub | regress_subscription_user | f | {testpub} | t | off | d | f | any | t | f | f | off | dbname=regress_doesnotexist | 0/0
+ List of subscriptions
+ Name | Owner | Enabled | Publication | Binary | Streaming | Two-phase commit | Disable on error | Origin | Password required | Run as owner? | Failover | Force alter | Synchronous commit | Conninfo | Skip LSN
+-----------------+---------------------------+---------+-------------+--------+-----------+------------------+------------------+--------+-------------------+---------------+----------+-------------+--------------------+-----------------------------+----------
+ regress_testsub | regress_subscription_user | f | {testpub} | t | off | d | f | any | t | f | f | f | off | dbname=regress_doesnotexist | 0/0
(1 row)
ALTER SUBSCRIPTION regress_testsub SET (binary = false);
ALTER SUBSCRIPTION regress_testsub SET (slot_name = NONE);
\dRs+
- List of subscriptions
- Name | Owner | Enabled | Publication | Binary | Streaming | Two-phase commit | Disable on error | Origin | Password required | Run as owner? | Failover | Synchronous commit | Conninfo | Skip LSN
------------------+---------------------------+---------+-------------+--------+-----------+------------------+------------------+--------+-------------------+---------------+----------+--------------------+-----------------------------+----------
- regress_testsub | regress_subscription_user | f | {testpub} | f | off | d | f | any | t | f | f | off | dbname=regress_doesnotexist | 0/0
+ List of subscriptions
+ Name | Owner | Enabled | Publication | Binary | Streaming | Two-phase commit | Disable on error | Origin | Password required | Run as owner? | Failover | Force alter | Synchronous commit | Conninfo | Skip LSN
+-----------------+---------------------------+---------+-------------+--------+-----------+------------------+------------------+--------+-------------------+---------------+----------+-------------+--------------------+-----------------------------+----------
+ regress_testsub | regress_subscription_user | f | {testpub} | f | off | d | f | any | t | f | f | f | off | dbname=regress_doesnotexist | 0/0
(1 row)
DROP SUBSCRIPTION regress_testsub;
@@ -279,27 +279,27 @@ CREATE SUBSCRIPTION regress_testsub CONNECTION 'dbname=regress_doesnotexist' PUB
WARNING: subscription was created, but is not connected
HINT: To initiate replication, you must manually create the replication slot, enable the subscription, and refresh the subscription.
\dRs+
- List of subscriptions
- Name | Owner | Enabled | Publication | Binary | Streaming | Two-phase commit | Disable on error | Origin | Password required | Run as owner? | Failover | Synchronous commit | Conninfo | Skip LSN
------------------+---------------------------+---------+-------------+--------+-----------+------------------+------------------+--------+-------------------+---------------+----------+--------------------+-----------------------------+----------
- regress_testsub | regress_subscription_user | f | {testpub} | f | on | d | f | any | t | f | f | off | dbname=regress_doesnotexist | 0/0
+ List of subscriptions
+ Name | Owner | Enabled | Publication | Binary | Streaming | Two-phase commit | Disable on error | Origin | Password required | Run as owner? | Failover | Force alter | Synchronous commit | Conninfo | Skip LSN
+-----------------+---------------------------+---------+-------------+--------+-----------+------------------+------------------+--------+-------------------+---------------+----------+-------------+--------------------+-----------------------------+----------
+ regress_testsub | regress_subscription_user | f | {testpub} | f | on | d | f | any | t | f | f | f | off | dbname=regress_doesnotexist | 0/0
(1 row)
ALTER SUBSCRIPTION regress_testsub SET (streaming = parallel);
\dRs+
- List of subscriptions
- Name | Owner | Enabled | Publication | Binary | Streaming | Two-phase commit | Disable on error | Origin | Password required | Run as owner? | Failover | Synchronous commit | Conninfo | Skip LSN
------------------+---------------------------+---------+-------------+--------+-----------+------------------+------------------+--------+-------------------+---------------+----------+--------------------+-----------------------------+----------
- regress_testsub | regress_subscription_user | f | {testpub} | f | parallel | d | f | any | t | f | f | off | dbname=regress_doesnotexist | 0/0
+ List of subscriptions
+ Name | Owner | Enabled | Publication | Binary | Streaming | Two-phase commit | Disable on error | Origin | Password required | Run as owner? | Failover | Force alter | Synchronous commit | Conninfo | Skip LSN
+-----------------+---------------------------+---------+-------------+--------+-----------+------------------+------------------+--------+-------------------+---------------+----------+-------------+--------------------+-----------------------------+----------
+ regress_testsub | regress_subscription_user | f | {testpub} | f | parallel | d | f | any | t | f | f | f | off | dbname=regress_doesnotexist | 0/0
(1 row)
ALTER SUBSCRIPTION regress_testsub SET (streaming = false);
ALTER SUBSCRIPTION regress_testsub SET (slot_name = NONE);
\dRs+
- List of subscriptions
- Name | Owner | Enabled | Publication | Binary | Streaming | Two-phase commit | Disable on error | Origin | Password required | Run as owner? | Failover | Synchronous commit | Conninfo | Skip LSN
------------------+---------------------------+---------+-------------+--------+-----------+------------------+------------------+--------+-------------------+---------------+----------+--------------------+-----------------------------+----------
- regress_testsub | regress_subscription_user | f | {testpub} | f | off | d | f | any | t | f | f | off | dbname=regress_doesnotexist | 0/0
+ List of subscriptions
+ Name | Owner | Enabled | Publication | Binary | Streaming | Two-phase commit | Disable on error | Origin | Password required | Run as owner? | Failover | Force alter | Synchronous commit | Conninfo | Skip LSN
+-----------------+---------------------------+---------+-------------+--------+-----------+------------------+------------------+--------+-------------------+---------------+----------+-------------+--------------------+-----------------------------+----------
+ regress_testsub | regress_subscription_user | f | {testpub} | f | off | d | f | any | t | f | f | f | off | dbname=regress_doesnotexist | 0/0
(1 row)
-- fail - publication already exists
@@ -314,10 +314,10 @@ ALTER SUBSCRIPTION regress_testsub ADD PUBLICATION testpub1, testpub2 WITH (refr
ALTER SUBSCRIPTION regress_testsub ADD PUBLICATION testpub1, testpub2 WITH (refresh = false);
ERROR: publication "testpub1" is already in subscription "regress_testsub"
\dRs+
- List of subscriptions
- Name | Owner | Enabled | Publication | Binary | Streaming | Two-phase commit | Disable on error | Origin | Password required | Run as owner? | Failover | Synchronous commit | Conninfo | Skip LSN
------------------+---------------------------+---------+-----------------------------+--------+-----------+------------------+------------------+--------+-------------------+---------------+----------+--------------------+-----------------------------+----------
- regress_testsub | regress_subscription_user | f | {testpub,testpub1,testpub2} | f | off | d | f | any | t | f | f | off | dbname=regress_doesnotexist | 0/0
+ List of subscriptions
+ Name | Owner | Enabled | Publication | Binary | Streaming | Two-phase commit | Disable on error | Origin | Password required | Run as owner? | Failover | Force alter | Synchronous commit | Conninfo | Skip LSN
+-----------------+---------------------------+---------+-----------------------------+--------+-----------+------------------+------------------+--------+-------------------+---------------+----------+-------------+--------------------+-----------------------------+----------
+ regress_testsub | regress_subscription_user | f | {testpub,testpub1,testpub2} | f | off | d | f | any | t | f | f | f | off | dbname=regress_doesnotexist | 0/0
(1 row)
-- fail - publication used more than once
@@ -332,10 +332,10 @@ ERROR: publication "testpub3" is not in subscription "regress_testsub"
-- ok - delete publications
ALTER SUBSCRIPTION regress_testsub DROP PUBLICATION testpub1, testpub2 WITH (refresh = false);
\dRs+
- List of subscriptions
- Name | Owner | Enabled | Publication | Binary | Streaming | Two-phase commit | Disable on error | Origin | Password required | Run as owner? | Failover | Synchronous commit | Conninfo | Skip LSN
------------------+---------------------------+---------+-------------+--------+-----------+------------------+------------------+--------+-------------------+---------------+----------+--------------------+-----------------------------+----------
- regress_testsub | regress_subscription_user | f | {testpub} | f | off | d | f | any | t | f | f | off | dbname=regress_doesnotexist | 0/0
+ List of subscriptions
+ Name | Owner | Enabled | Publication | Binary | Streaming | Two-phase commit | Disable on error | Origin | Password required | Run as owner? | Failover | Force alter | Synchronous commit | Conninfo | Skip LSN
+-----------------+---------------------------+---------+-------------+--------+-----------+------------------+------------------+--------+-------------------+---------------+----------+-------------+--------------------+-----------------------------+----------
+ regress_testsub | regress_subscription_user | f | {testpub} | f | off | d | f | any | t | f | f | f | off | dbname=regress_doesnotexist | 0/0
(1 row)
DROP SUBSCRIPTION regress_testsub;
@@ -371,19 +371,19 @@ CREATE SUBSCRIPTION regress_testsub CONNECTION 'dbname=regress_doesnotexist' PUB
WARNING: subscription was created, but is not connected
HINT: To initiate replication, you must manually create the replication slot, enable the subscription, and refresh the subscription.
\dRs+
- List of subscriptions
- Name | Owner | Enabled | Publication | Binary | Streaming | Two-phase commit | Disable on error | Origin | Password required | Run as owner? | Failover | Synchronous commit | Conninfo | Skip LSN
------------------+---------------------------+---------+-------------+--------+-----------+------------------+------------------+--------+-------------------+---------------+----------+--------------------+-----------------------------+----------
- regress_testsub | regress_subscription_user | f | {testpub} | f | off | p | f | any | t | f | f | off | dbname=regress_doesnotexist | 0/0
+ List of subscriptions
+ Name | Owner | Enabled | Publication | Binary | Streaming | Two-phase commit | Disable on error | Origin | Password required | Run as owner? | Failover | Force alter | Synchronous commit | Conninfo | Skip LSN
+-----------------+---------------------------+---------+-------------+--------+-----------+------------------+------------------+--------+-------------------+---------------+----------+-------------+--------------------+-----------------------------+----------
+ regress_testsub | regress_subscription_user | f | {testpub} | f | off | p | f | any | t | f | f | f | off | dbname=regress_doesnotexist | 0/0
(1 row)
-- We can alter streaming when two_phase enabled
ALTER SUBSCRIPTION regress_testsub SET (streaming = true);
\dRs+
- List of subscriptions
- Name | Owner | Enabled | Publication | Binary | Streaming | Two-phase commit | Disable on error | Origin | Password required | Run as owner? | Failover | Synchronous commit | Conninfo | Skip LSN
------------------+---------------------------+---------+-------------+--------+-----------+------------------+------------------+--------+-------------------+---------------+----------+--------------------+-----------------------------+----------
- regress_testsub | regress_subscription_user | f | {testpub} | f | on | p | f | any | t | f | f | off | dbname=regress_doesnotexist | 0/0
+ List of subscriptions
+ Name | Owner | Enabled | Publication | Binary | Streaming | Two-phase commit | Disable on error | Origin | Password required | Run as owner? | Failover | Force alter | Synchronous commit | Conninfo | Skip LSN
+-----------------+---------------------------+---------+-------------+--------+-----------+------------------+------------------+--------+-------------------+---------------+----------+-------------+--------------------+-----------------------------+----------
+ regress_testsub | regress_subscription_user | f | {testpub} | f | on | p | f | any | t | f | f | f | off | dbname=regress_doesnotexist | 0/0
(1 row)
ALTER SUBSCRIPTION regress_testsub SET (slot_name = NONE);
@@ -393,10 +393,10 @@ CREATE SUBSCRIPTION regress_testsub CONNECTION 'dbname=regress_doesnotexist' PUB
WARNING: subscription was created, but is not connected
HINT: To initiate replication, you must manually create the replication slot, enable the subscription, and refresh the subscription.
\dRs+
- List of subscriptions
- Name | Owner | Enabled | Publication | Binary | Streaming | Two-phase commit | Disable on error | Origin | Password required | Run as owner? | Failover | Synchronous commit | Conninfo | Skip LSN
------------------+---------------------------+---------+-------------+--------+-----------+------------------+------------------+--------+-------------------+---------------+----------+--------------------+-----------------------------+----------
- regress_testsub | regress_subscription_user | f | {testpub} | f | on | p | f | any | t | f | f | off | dbname=regress_doesnotexist | 0/0
+ List of subscriptions
+ Name | Owner | Enabled | Publication | Binary | Streaming | Two-phase commit | Disable on error | Origin | Password required | Run as owner? | Failover | Force alter | Synchronous commit | Conninfo | Skip LSN
+-----------------+---------------------------+---------+-------------+--------+-----------+------------------+------------------+--------+-------------------+---------------+----------+-------------+--------------------+-----------------------------+----------
+ regress_testsub | regress_subscription_user | f | {testpub} | f | on | p | f | any | t | f | f | f | off | dbname=regress_doesnotexist | 0/0
(1 row)
ALTER SUBSCRIPTION regress_testsub SET (slot_name = NONE);
@@ -409,18 +409,18 @@ CREATE SUBSCRIPTION regress_testsub CONNECTION 'dbname=regress_doesnotexist' PUB
WARNING: subscription was created, but is not connected
HINT: To initiate replication, you must manually create the replication slot, enable the subscription, and refresh the subscription.
\dRs+
- List of subscriptions
- Name | Owner | Enabled | Publication | Binary | Streaming | Two-phase commit | Disable on error | Origin | Password required | Run as owner? | Failover | Synchronous commit | Conninfo | Skip LSN
------------------+---------------------------+---------+-------------+--------+-----------+------------------+------------------+--------+-------------------+---------------+----------+--------------------+-----------------------------+----------
- regress_testsub | regress_subscription_user | f | {testpub} | f | off | d | f | any | t | f | f | off | dbname=regress_doesnotexist | 0/0
+ List of subscriptions
+ Name | Owner | Enabled | Publication | Binary | Streaming | Two-phase commit | Disable on error | Origin | Password required | Run as owner? | Failover | Force alter | Synchronous commit | Conninfo | Skip LSN
+-----------------+---------------------------+---------+-------------+--------+-----------+------------------+------------------+--------+-------------------+---------------+----------+-------------+--------------------+-----------------------------+----------
+ regress_testsub | regress_subscription_user | f | {testpub} | f | off | d | f | any | t | f | f | f | off | dbname=regress_doesnotexist | 0/0
(1 row)
ALTER SUBSCRIPTION regress_testsub SET (disable_on_error = true);
\dRs+
- List of subscriptions
- Name | Owner | Enabled | Publication | Binary | Streaming | Two-phase commit | Disable on error | Origin | Password required | Run as owner? | Failover | Synchronous commit | Conninfo | Skip LSN
------------------+---------------------------+---------+-------------+--------+-----------+------------------+------------------+--------+-------------------+---------------+----------+--------------------+-----------------------------+----------
- regress_testsub | regress_subscription_user | f | {testpub} | f | off | d | t | any | t | f | f | off | dbname=regress_doesnotexist | 0/0
+ List of subscriptions
+ Name | Owner | Enabled | Publication | Binary | Streaming | Two-phase commit | Disable on error | Origin | Password required | Run as owner? | Failover | Force alter | Synchronous commit | Conninfo | Skip LSN
+-----------------+---------------------------+---------+-------------+--------+-----------+------------------+------------------+--------+-------------------+---------------+----------+-------------+--------------------+-----------------------------+----------
+ regress_testsub | regress_subscription_user | f | {testpub} | f | off | d | t | any | t | f | f | f | off | dbname=regress_doesnotexist | 0/0
(1 row)
ALTER SUBSCRIPTION regress_testsub SET (slot_name = NONE);
diff --git a/src/test/subscription/t/099_twophase_added.pl b/src/test/subscription/t/099_twophase_added.pl
index 7abe1c37d5..188a3fa7a3 100644
--- a/src/test/subscription/t/099_twophase_added.pl
+++ b/src/test/subscription/t/099_twophase_added.pl
@@ -97,7 +97,8 @@ is($result, q(5),
# Check the case that prepared transactions exist on the subscriber node
#
# If the two_phase is altering from "on" to "off" and there are prepared
-# transactions on the subscriber, they must be aborted. This test checks it.
+# transactions on the subscriber, we must error out or abort all prepared
+# transactions. Below part checks both cases.
# Prepare a transaction to insert some tuples into the table
$node_publisher->safe_psql(
@@ -114,15 +115,39 @@ $result = $node_subscriber->safe_psql('postgres',
"SELECT count(*) FROM pg_prepared_xacts;");
is($result, q(1), "transaction has been prepared on subscriber");
-# Toggle the two_phase to "off" before the COMMIT PREPARED
-$node_subscriber->safe_psql(
- 'postgres', "
- ALTER SUBSCRIPTION regress_sub DISABLE;
- ALTER SUBSCRIPTION regress_sub SET (two_phase = off);
- ALTER SUBSCRIPTION regress_sub ENABLE;");
+# Disable the subscription to alter the two_phase option
+$node_subscriber->safe_psql('postgres', "ALTER SUBSCRIPTION regress_sub DISABLE;");
+
+# Try altering the two_phase option to "off." The command will fail since there
+# is a prepared transaction and the 'force_alter' option is not specified as
+# true.
+my $stdout;
+my $stderr;
+
+($result, $stdout, $stderr) = $node_subscriber->psql(
+ 'postgres', "ALTER SUBSCRIPTION regress_sub SET (two_phase = false);");
+ok($stderr =~ /cannot alter two_phase = false when there are prepared transactions/,
+ 'ALTER SUBSCRIPTION failed');
+
+# Verify the prepared transaction still exists
+$result = $node_subscriber->safe_psql('postgres',
+ "SELECT count(*) FROM pg_prepared_xacts;");
+is($result, q(1), "prepared transaction still exists");
+
+$log_offset = -s $node_subscriber->logfile;
+
+# Alter the two_phase with the force_alter option. Apart from the the last
+# ALTER SUBSCRIPTION command, the command will abort the prepared transaction
+# and succeed.
+$node_subscriber->safe_psql('postgres',
+ "ALTER SUBSCRIPTION regress_sub SET (two_phase = off, force_alter = true);");
+$node_subscriber->safe_psql('postgres', "ALTER SUBSCRIPTION regress_sub ENABLE;");
+
+# Verify the started worker recognized two_phase was disabled
+$node_subscriber->wait_for_log(
+ 'logical replication apply worker for subscription "regress_sub" two_phase is DISABLED', $log_offset);
-# Verify any prepared transactions are aborted because two_phase is changed to
-# "off".
+# Verify the prepared transaction was aborted
$result = $node_subscriber->safe_psql('postgres',
"SELECT count(*) FROM pg_prepared_xacts;");
is($result, q(0), "prepared transaction done by worker is aborted");
--
2.43.0
^ permalink raw reply [nested|flat] 25+ messages in thread
* Re: Slow catchup of 2PC (twophase) transactions on replica in LR
@ 2024-05-15 05:02 Peter Smith <[email protected]>
parent: Hayato Kuroda (Fujitsu) <[email protected]>
1 sibling, 1 reply; 25+ messages in thread
From: Peter Smith @ 2024-05-15 05:02 UTC (permalink / raw)
To: Hayato Kuroda (Fujitsu) <[email protected]>; +Cc: [email protected] <[email protected]>; Amit Kapila <[email protected]>; Ajin Cherian <[email protected]>; Давыдов Виталий <[email protected]>
Hi Kuroda-san. Here are my review comments for latest v10* patches.
//////////
patch v10-0001
//////////
No changes. No comments.
//////////
patch v10-0002
//////////
======
Commit message
2.1.
Regarding the false->true case, the backend process alters the subtwophase to
LOGICALREP_TWOPHASE_STATE_PENDING once. After the subscription is enabled, a new
logical replication worker requests to change the two_phase option of its slot
from pending to true after the initial data synchronization is done. The code
path is the same as the case in which two_phase is initially set to true, so
there is no need to do something remarkable. However, for the true->false case,
the backend must connect to the publisher and expressly change the parameter
because the apply worker does not alter the option to false. The
operation cannot
be rolled back, and altering the parameter from "true" to "false" within a
transaction is prohibited.
~
BEFORE
The operation cannot be rolled back, and altering the parameter from
"true" to "false" within a transaction is prohibited.
SUGGESTION
Because this operation cannot be rolled back, altering the two_phase
parameter from "true" to "false" within a transaction is prohibited.
======
doc/src/sgml/ref/alter_subscription.sgml
2.2.
<command>ALTER SUBSCRIPTION ... SET (failover = on|off)</command> and
- <command>ALTER SUBSCRIPTION ... SET (two_phase = on|off)</command>
+ <command>ALTER SUBSCRIPTION ... SET (two_phase = off)</command>
I wasn't sure why you chose to keep on|off here instead of true|false,
since in subsequence patch 0003 you changed it true/false everywhere
as discussed in previous reviews.
OTOH if you only did this to be consistent with the "failover=on|off"
then that is OK; but in that case I might raise a separate hackers
thread to propose those should also be changed to true|false for
consistency with the parameer listed on the CREATE SUBSCRIPTION page.
What do you think?
======
src/backend/commands/subscriptioncmds.c
2.3.
/*
- * The changed two_phase option of the slot can't be rolled
- * back.
+ * Altering the parameter from "true" to "false" within a
+ * transaction is prohibited. Since the apply worker does
+ * not alter the slot option to false, the backend must
+ * connect to the publisher and expressly change the
+ * parameter.
+ *
+ * There is no need to do something remarkable regarding
+ * the "false" to "true" case; the backend process alters
+ * subtwophase to LOGICALREP_TWOPHASE_STATE_PENDING once.
+ * After the subscription is enabled, a new logical
+ * replication worker requests to change the two_phase
+ * option of its slot when the initial data synchronization
+ * is done. The code path is the same as the case in which
+ * two_phase is initially set to true.
*/
BEFORE
...worker requests to change the two_phase option of its slot when...
SUGGESTION
...worker requests to change the two_phase option of its slot from
pending to true when...
======
src/test/subscription/t/099_twophase_added.pl
2.4.
+#####################
+# Check the case that prepared transactions exist on the publisher node.
+#
+# Since the two_phase is "off", then normally, this PREPARE will do nothing
+# until the COMMIT PREPARED, but in this test, we toggle the two_phase to
+# "true" again before the COMMIT PREPARED happens.
/Since the two_phase is "off"/Since the two_phase is "false"/
//////////
patch v10-0003
//////////
======
src/backend/commands/subscriptioncmds.c
3.1. AlterSubscription
+ * If two_phase was enabled, there is a possibility that
+ * transactions have already been PREPARE'd. They must be
+ * checked and rolled back.
*/
if (!opts.twophase)
I think it will less ambiguous if you modify this to say "If two_phase
was previously enabled"
~~~
3.2.
if (!opts.twophase)
{
List *prepared_xacts;
/*
* Altering the parameter from "true" to "false" within
* a transaction is prohibited. Since the apply worker
* does not alter the slot option to false, the backend
* must connect to the publisher and expressly change
* the parameter.
*
* There is no need to do something remarkable
* regarding the "false" to "true" case; the backend
* process alters subtwophase to
* LOGICALREP_TWOPHASE_STATE_PENDING once. After the
* subscription is enabled, a new logical replication
* worker requests to change the two_phase option of
* its slot when the initial data synchronization is
* done. The code path is the same as the case in which
* two_phase is initially set to true.
*/
if (!opts.twophase)
PreventInTransactionBlock(isTopLevel,
"ALTER SUBSCRIPTION ... SET (two_phase = false)");
/*
* To prevent prepared transactions from being
* isolated, they must manually be aborted.
*/
if (sub->twophasestate == LOGICALREP_TWOPHASE_STATE_ENABLED &&
(prepared_xacts = GetGidListBySubid(subid)) != NIL)
{
/* Abort all listed transactions */
foreach_ptr(char, gid, prepared_xacts)
FinishPreparedTransaction(gid, false);
list_free_deep(prepared_xacts);
}
}
/* Change system catalog acoordingly */
values[Anum_pg_subscription_subtwophasestate - 1] =
CharGetDatum(opts.twophase ?
LOGICALREP_TWOPHASE_STATE_PENDING :
LOGICALREP_TWOPHASE_STATE_DISABLED);
replaces[Anum_pg_subscription_subtwophasestate - 1] = true;
}
~
Why is "if (!opts.twophase)" being checked at the top and then
immediately being checed again here:
+ if (!opts.twophase)
+ PreventInTransactionBlock(isTopLevel,
+ "ALTER SUBSCRIPTION ... SET (two_phase = false)");
And then again here:
CharGetDatum(opts.twophase ?
LOGICALREP_TWOPHASE_STATE_PENDING :
LOGICALREP_TWOPHASE_STATE_DISABLED);
There is no need to re-check a flag that was already checked, so
clearly some of this logic/code is either wrong or redundant.
======
src/test/subscription/t/099_twophase_added.pl
(Let's change these on|off to true|false to match what you did already
in patch 0002).
3.3.
+#####################
+# Check the case that prepared transactions exist on the subscriber node
+#
+# If the two_phase is altering from "on" to "off" and there are prepared
+# transactions on the subscriber, they must be aborted. This test checks it.
/off/false/
/on/true/
~~~
3.4.
+# Verify the prepared transaction has been replicated to the subscriber because
+# two_phase is set to "on".
/on/true/
~~~
3.5.
+# Toggle the two_phase to "off" before the COMMIT PREPARED
+$node_subscriber->safe_psql(
+ 'postgres', "
+ ALTER SUBSCRIPTION regress_sub DISABLE;
+ ALTER SUBSCRIPTION regress_sub SET (two_phase = off);
+ ALTER SUBSCRIPTION regress_sub ENABLE;");
/off/false/
/two_phase = off/two_phase = false/
~~~
3.6.
+# Verify any prepared transactions are aborted because two_phase is changed to
+# "off".
/off/false/
//////////
patch v10-0004
//////////
======
4.g1. GENERAL - document rendering fails
FYI - The document failed to build after I apply patch 0003. Did you try it?
In my environment it reported some unbalanced tags:
ref/create_subscription.sgml:448: parser error : Opening and ending
tag mismatch: link line 436 and para
</para>
^
ref/create_subscription.sgml:449: parser error : Opening and ending
tag mismatch: para line 435 and listitem
</listitem>
etc.
======
doc/src/sgml/ref/alter_subscription.sgml
4.1.
<para>
The <literal>two_phase</literal> parameter can only be altered when the
- subscription is disabled. When altering the parameter from
<literal>true</literal>
- to <literal>false</literal>, the backend process checks for any
incomplete
- prepared transactions done by the logical replication worker (from when
- <literal>two_phase</literal> parameter was still <literal>true</literal>)
- and, if any are found, those are aborted.
+ subscription is disabled. Altering the parameter from
<literal>true</literal>
+ to <literal>false</literal> will give an error when when there are
+ prepared transactions done by the logical replication worker. If you want
+ to alter the parameter forcibly in this case,
+ <link linkend="sql-createsubscription-params-with-force-alter"><literal>force_alter</literal></link>
+ option must be set to <literal>true</literal> at the same time.
</para>
TYPO: "when when"
Why is necessary to say "at the same time"?
======
doc/src/sgml/ref/create_subscription.sgml
4.2.
+ <varlistentry id="sql-createsubscription-params-with-force-alter">
+ <term><literal>force_alter</literal> (<type>boolean</type>)</term>
+ <listitem>
+ <para>
+ Specifies if the <link
linkend="sql-altersubscription"><command>ALTER SUBSCRIPTION</command>
+ can be forced to proceed instead of giving an error. There is
+ currently only one scenario where this parameter has any effect: When
+ altering <literal>two_phase</literal> option from
<literal>true</literal>
+ to <literal>false</literal> it is possible for there to be incomplete
+ prepared transactions done by the logical replication worker (from
+ when <literal>two_phase</literal> parameter was still
<literal>true</literal>).
+ If <literal>force_alter</literal> is <literal>false</literal>, then
+ this will give an error; if <literal>force_alter</literal> is
+ <literal>true</literal>, then the incomplete prepared transactions
+ are aborted and the alter will proceed.
+ The default is <literal>false</literal>.
+ </para>
+ </listitem>
+ </varlistentry>
IMO this will be better broken into multiple paragraphs.
1. Specifies...
2. There is...
3. The default is...
======
src/test/subscription/t/099_twophase_added.pl
(Let's change all the on|off to true|false like you already did in patch 0002.
4.3.
+# Try altering the two_phase option to "off." The command will fail since there
+# is a prepared transaction and the 'force_alter' option is not specified as
+# true.
+my $stdout;
+my $stderr;
/off./false/
======
Kind Regards,
Peter Smith.
Fujitsu Australia
^ permalink raw reply [nested|flat] 25+ messages in thread
* Re: Slow catchup of 2PC (twophase) transactions on replica in LR
@ 2024-05-15 05:12 Peter Smith <[email protected]>
parent: Hayato Kuroda (Fujitsu) <[email protected]>
1 sibling, 1 reply; 25+ messages in thread
From: Peter Smith @ 2024-05-15 05:12 UTC (permalink / raw)
To: Hayato Kuroda (Fujitsu) <[email protected]>; +Cc: [email protected] <[email protected]>; Amit Kapila <[email protected]>; Ajin Cherian <[email protected]>; Давыдов Виталий <[email protected]>
On Tue, May 14, 2024 at 10:03 PM Hayato Kuroda (Fujitsu)
<[email protected]> wrote:
>
> Dear Peter,
>
...
> > 4.11.
> >
> > +# Alter the two_phase with the force_alter option. Apart from the the last
> > +# ALTER SUBSCRIPTION command, the command will abort the prepared
> > transaction
> > +# and succeed.
> >
> > There is typo "the the" and the wording is a bit strange. Why not just say:
> >
> > SUGGESTION
> > Alter the two_phase true to false with the force_alter option enabled.
> > This command will succeed after aborting the prepared transaction.
>
> Fixed.
>
You wrote "Fixed" for that patch v9-0004 suggestion but I don't think
anything was changed at all. Accidentally missed?
======
Kind Regards,
Peter Smith.
Futjisu Australia
^ permalink raw reply [nested|flat] 25+ messages in thread
* RE: Slow catchup of 2PC (twophase) transactions on replica in LR
@ 2024-05-16 05:02 Hayato Kuroda (Fujitsu) <[email protected]>
parent: Peter Smith <[email protected]>
0 siblings, 1 reply; 25+ messages in thread
From: Hayato Kuroda (Fujitsu) @ 2024-05-16 05:02 UTC (permalink / raw)
To: 'Peter Smith' <[email protected]>; +Cc: [email protected] <[email protected]>; Amit Kapila <[email protected]>; Ajin Cherian <[email protected]>; Давыдов Виталий <[email protected]>
Dear Peter,
Thanks for reviewing! Here are new patches.
>
> //////////
> patch v10-0002
> //////////
>
> ======
> Commit message
>
> 2.1.
> Regarding the false->true case, the backend process alters the subtwophase to
> LOGICALREP_TWOPHASE_STATE_PENDING once. After the subscription is
> enabled, a new
> logical replication worker requests to change the two_phase option of its slot
> from pending to true after the initial data synchronization is done. The code
> path is the same as the case in which two_phase is initially set to true, so
> there is no need to do something remarkable. However, for the true->false case,
> the backend must connect to the publisher and expressly change the parameter
> because the apply worker does not alter the option to false. The
> operation cannot
> be rolled back, and altering the parameter from "true" to "false" within a
> transaction is prohibited.
>
> ~
>
> BEFORE
> The operation cannot be rolled back, and altering the parameter from
> "true" to "false" within a transaction is prohibited.
>
> SUGGESTION
> Because this operation cannot be rolled back, altering the two_phase
> parameter from "true" to "false" within a transaction is prohibited.
Fixed.
>
> ======
> doc/src/sgml/ref/alter_subscription.sgml
>
> 2.2.
> <command>ALTER SUBSCRIPTION ... SET (failover = on|off)</command>
> and
> - <command>ALTER SUBSCRIPTION ... SET (two_phase =
> on|off)</command>
> + <command>ALTER SUBSCRIPTION ... SET (two_phase = off)</command>
>
> I wasn't sure why you chose to keep on|off here instead of true|false,
> since in subsequence patch 0003 you changed it true/false everywhere
> as discussed in previous reviews.
>
> OTOH if you only did this to be consistent with the "failover=on|off"
> then that is OK; but in that case I might raise a separate hackers
> thread to propose those should also be changed to true|false for
> consistency with the parameer listed on the CREATE SUBSCRIPTION page.
> What do you think?
Yeah, I did not change here, because other parameters were notated as
on/off. I found you started the forked thread [1] so I will revise the patch
after it was accepted.
>
> ======
> src/backend/commands/subscriptioncmds.c
>
> 2.3.
> /*
> - * The changed two_phase option of the slot can't be rolled
> - * back.
> + * Altering the parameter from "true" to "false" within a
> + * transaction is prohibited. Since the apply worker does
> + * not alter the slot option to false, the backend must
> + * connect to the publisher and expressly change the
> + * parameter.
> + *
> + * There is no need to do something remarkable regarding
> + * the "false" to "true" case; the backend process alters
> + * subtwophase to LOGICALREP_TWOPHASE_STATE_PENDING once.
> + * After the subscription is enabled, a new logical
> + * replication worker requests to change the two_phase
> + * option of its slot when the initial data synchronization
> + * is done. The code path is the same as the case in which
> + * two_phase is initially set to true.
> */
>
> BEFORE
> ...worker requests to change the two_phase option of its slot when...
>
> SUGGESTION
> ...worker requests to change the two_phase option of its slot from
> pending to true when...
Fixed.
>
> ======
> src/test/subscription/t/099_twophase_added.pl
>
> 2.4.
> +#####################
> +# Check the case that prepared transactions exist on the publisher node.
> +#
> +# Since the two_phase is "off", then normally, this PREPARE will do nothing
> +# until the COMMIT PREPARED, but in this test, we toggle the two_phase to
> +# "true" again before the COMMIT PREPARED happens.
>
> /Since the two_phase is "off"/Since the two_phase is "false"/
Fixed.
>
> //////////
> patch v10-0003
> //////////
>
> ======
> src/backend/commands/subscriptioncmds.c
>
> 3.1. AlterSubscription
>
> + * If two_phase was enabled, there is a possibility that
> + * transactions have already been PREPARE'd. They must be
> + * checked and rolled back.
> */
> if (!opts.twophase)
>
> I think it will less ambiguous if you modify this to say "If two_phase
> was previously enabled"
Fixed.
>
> ~~~
>
> 3.2.
> if (!opts.twophase)
> {
> List *prepared_xacts;
>
> /*
> * Altering the parameter from "true" to "false" within
> * a transaction is prohibited. Since the apply worker
> * does not alter the slot option to false, the backend
> * must connect to the publisher and expressly change
> * the parameter.
> *
> * There is no need to do something remarkable
> * regarding the "false" to "true" case; the backend
> * process alters subtwophase to
> * LOGICALREP_TWOPHASE_STATE_PENDING once. After the
> * subscription is enabled, a new logical replication
> * worker requests to change the two_phase option of
> * its slot when the initial data synchronization is
> * done. The code path is the same as the case in which
> * two_phase is initially set to true.
> */
> if (!opts.twophase)
> PreventInTransactionBlock(isTopLevel,
> "ALTER SUBSCRIPTION ... SET (two_phase = false)");
>
> /*
> * To prevent prepared transactions from being
> * isolated, they must manually be aborted.
> */
> if (sub->twophasestate == LOGICALREP_TWOPHASE_STATE_ENABLED &&
> (prepared_xacts = GetGidListBySubid(subid)) != NIL)
> {
> /* Abort all listed transactions */
> foreach_ptr(char, gid, prepared_xacts)
> FinishPreparedTransaction(gid, false);
>
> list_free_deep(prepared_xacts);
> }
> }
>
> /* Change system catalog acoordingly */
> values[Anum_pg_subscription_subtwophasestate - 1] =
> CharGetDatum(opts.twophase ?
> LOGICALREP_TWOPHASE_STATE_PENDING :
> LOGICALREP_TWOPHASE_STATE_DISABLED);
> replaces[Anum_pg_subscription_subtwophasestate - 1] = true;
> }
>
> ~
>
> Why is "if (!opts.twophase)" being checked at the top and then
> immediately being checed again here:
> + if (!opts.twophase)
> + PreventInTransactionBlock(isTopLevel,
> + "ALTER SUBSCRIPTION ... SET (two_phase = false)");
Oh, this was caused by wrong git operations.
> And then again here:
> CharGetDatum(opts.twophase ?
> LOGICALREP_TWOPHASE_STATE_PENDING :
> LOGICALREP_TWOPHASE_STATE_DISABLED);
>
> There is no need to re-check a flag that was already checked, so
> clearly some of this logic/code is either wrong or redundant.
Right. I added a new variable to store the value to be changed. Thouth?
>
> ======
> src/test/subscription/t/099_twophase_added.pl
>
> (Let's change these on|off to true|false to match what you did already
> in patch 0002).
>
> 3.3.
> +#####################
> +# Check the case that prepared transactions exist on the subscriber node
> +#
> +# If the two_phase is altering from "on" to "off" and there are prepared
> +# transactions on the subscriber, they must be aborted. This test checks it.
>
>
> /off/false/
>
> /on/true/
Fixed.
>
> ~~~
>
> 3.4.
> +# Verify the prepared transaction has been replicated to the subscriber because
> +# two_phase is set to "on".
>
> /on/true/
Fixed.
>
> ~~~
>
> 3.5.
> +# Toggle the two_phase to "off" before the COMMIT PREPARED
> +$node_subscriber->safe_psql(
> + 'postgres', "
> + ALTER SUBSCRIPTION regress_sub DISABLE;
> + ALTER SUBSCRIPTION regress_sub SET (two_phase = off);
> + ALTER SUBSCRIPTION regress_sub ENABLE;");
>
> /off/false/
>
> /two_phase = off/two_phase = false/
Fixed.
>
> ~~~
>
> 3.6.
> +# Verify any prepared transactions are aborted because two_phase is changed
> to
> +# "off".
>
> /off/false/
Fixed.
>
> //////////
> patch v10-0004
> //////////
>
> ======
> 4.g1. GENERAL - document rendering fails
>
> FYI - The document failed to build after I apply patch 0003. Did you try it?
>
> In my environment it reported some unbalanced tags:
>
> ref/create_subscription.sgml:448: parser error : Opening and ending
> tag mismatch: link line 436 and para
> </para>
> ^
> ref/create_subscription.sgml:449: parser error : Opening and ending
> tag mismatch: para line 435 and listitem
> </listitem>
>
> etc.
Oh, I forgot to run `make check`. Sorry. It seemed that I missed to close <link> tag.
>
> ======
> doc/src/sgml/ref/alter_subscription.sgml
>
> 4.1.
> <para>
> The <literal>two_phase</literal> parameter can only be altered when
> the
> - subscription is disabled. When altering the parameter from
> <literal>true</literal>
> - to <literal>false</literal>, the backend process checks for any
> incomplete
> - prepared transactions done by the logical replication worker (from when
> - <literal>two_phase</literal> parameter was still
> <literal>true</literal>)
> - and, if any are found, those are aborted.
> + subscription is disabled. Altering the parameter from
> <literal>true</literal>
> + to <literal>false</literal> will give an error when when there are
> + prepared transactions done by the logical replication worker. If you want
> + to alter the parameter forcibly in this case,
> + <link
> linkend="sql-createsubscription-params-with-force-alter"><literal>force_alter
> </literal></link>
> + option must be set to <literal>true</literal> at the same time.
> </para>
>
> TYPO: "when when"
Removed.
> Why is necessary to say "at the same time"?
Not needed. Fixed.
>
> ======
> doc/src/sgml/ref/create_subscription.sgml
>
> 4.2.
> + <varlistentry id="sql-createsubscription-params-with-force-alter">
> + <term><literal>force_alter</literal>
> (<type>boolean</type>)</term>
> + <listitem>
> + <para>
> + Specifies if the <link
> linkend="sql-altersubscription"><command>ALTER
> SUBSCRIPTION</command>
> + can be forced to proceed instead of giving an error. There is
> + currently only one scenario where this parameter has any effect:
> When
> + altering <literal>two_phase</literal> option from
> <literal>true</literal>
> + to <literal>false</literal> it is possible for there to be incomplete
> + prepared transactions done by the logical replication worker (from
> + when <literal>two_phase</literal> parameter was still
> <literal>true</literal>).
> + If <literal>force_alter</literal> is <literal>false</literal>, then
> + this will give an error; if <literal>force_alter</literal> is
> + <literal>true</literal>, then the incomplete prepared transactions
> + are aborted and the alter will proceed.
> + The default is <literal>false</literal>.
> + </para>
> + </listitem>
> + </varlistentry>
>
> IMO this will be better broken into multiple paragraphs.
>
> 1. Specifies...
> 2. There is...
> 3. The default is...
Separated.
>
> ======
> src/test/subscription/t/099_twophase_added.pl
>
> (Let's change all the on|off to true|false like you already did in patch 0002.
>
> 4.3.
> +# Try altering the two_phase option to "off." The command will fail since there
> +# is a prepared transaction and the 'force_alter' option is not specified as
> +# true.
> +my $stdout;
> +my $stderr;
>
> /off./false/
Fixed.
[1]: https://www.postgresql.org/message-id/CAHut%2BPs-RqrggaJU5w85BbeQzw9CLmmLgADVJoJ%3Dxx_4D5CWvw%40mail...
Best Regards,
Hayato Kuroda
FUJITSU LIMITED
https://www.fujitsu.com/
Attachments:
[application/octet-stream] v11-0001-Allow-altering-of-two_phase-option-of-a-SUBSCRIP.patch (25.5K, ../../OSBPR01MB25522052F9F3E3AAD3BA2A8CF5ED2@OSBPR01MB2552.jpnprd01.prod.outlook.com/2-v11-0001-Allow-altering-of-two_phase-option-of-a-SUBSCRIP.patch)
download | inline diff:
From bd3ff2c6e88a7dd5578cfd266848b824c1ff8546 Mon Sep 17 00:00:00 2001
From: Ajin Cherian <[email protected]>
Date: Fri, 5 Apr 2024 06:47:18 -0400
Subject: [PATCH v11 1/4] Allow altering of two_phase option of a SUBSCRIPTION
This patch allows the user to alter the 'two_phase' option of a subscriber provided no
uncommitted prepared transactions are pending on that subscription.
Author: Cherian Ajin, Hayato Kuroda
---
doc/src/sgml/ref/alter_subscription.sgml | 12 ++--
src/backend/access/transam/twophase.c | 62 ++++++++++++++++
src/backend/commands/subscriptioncmds.c | 67 +++++++++++++----
.../libpqwalreceiver/libpqwalreceiver.c | 9 +--
src/backend/replication/logical/launcher.c | 22 ++++++
src/backend/replication/logical/worker.c | 21 +-----
src/backend/replication/slot.c | 18 ++++-
src/backend/replication/walsender.c | 18 ++++-
src/bin/psql/tab-complete.c | 2 +-
src/include/access/twophase.h | 5 ++
src/include/replication/slot.h | 3 +-
src/include/replication/walreceiver.h | 11 +--
src/include/replication/worker_internal.h | 1 +
src/test/regress/expected/subscription.out | 5 +-
src/test/regress/sql/subscription.sql | 5 +-
src/test/subscription/t/021_twophase.pl | 71 ++++++++++++++++++-
16 files changed, 269 insertions(+), 63 deletions(-)
diff --git a/doc/src/sgml/ref/alter_subscription.sgml b/doc/src/sgml/ref/alter_subscription.sgml
index a78c1c3a47..88e9a72147 100644
--- a/doc/src/sgml/ref/alter_subscription.sgml
+++ b/doc/src/sgml/ref/alter_subscription.sgml
@@ -68,8 +68,9 @@ ALTER SUBSCRIPTION <replaceable class="parameter">name</replaceable> RENAME TO <
<para>
Commands <command>ALTER SUBSCRIPTION ... REFRESH PUBLICATION</command>,
<command>ALTER SUBSCRIPTION ... {SET|ADD|DROP} PUBLICATION ...</command>
- with <literal>refresh</literal> option as <literal>true</literal> and
- <command>ALTER SUBSCRIPTION ... SET (failover = on|off)</command>
+ with <literal>refresh</literal> option as <literal>true</literal>,
+ <command>ALTER SUBSCRIPTION ... SET (failover = on|off)</command> and
+ <command>ALTER SUBSCRIPTION ... SET (two_phase = on|off)</command>
cannot be executed inside a transaction block.
These commands also cannot be executed when the subscription has
@@ -228,9 +229,12 @@ ALTER SUBSCRIPTION <replaceable class="parameter">name</replaceable> RENAME TO <
<link linkend="sql-createsubscription-params-with-disable-on-error"><literal>disable_on_error</literal></link>,
<link linkend="sql-createsubscription-params-with-password-required"><literal>password_required</literal></link>,
<link linkend="sql-createsubscription-params-with-run-as-owner"><literal>run_as_owner</literal></link>,
- <link linkend="sql-createsubscription-params-with-origin"><literal>origin</literal></link>, and
- <link linkend="sql-createsubscription-params-with-failover"><literal>failover</literal></link>.
+ <link linkend="sql-createsubscription-params-with-origin"><literal>origin</literal></link>,
+ <link linkend="sql-createsubscription-params-with-failover"><literal>failover</literal></link>, and
+ <link linkend="sql-createsubscription-params-with-two-phase"><literal>two_phase</literal></link>.
Only a superuser can set <literal>password_required = false</literal>.
+ The <literal>two_phase</literal> parameter can only be altered when the
+ subscription is disabled.
</para>
<para>
diff --git a/src/backend/access/transam/twophase.c b/src/backend/access/transam/twophase.c
index 8090ac9fc1..66fa591eb5 100644
--- a/src/backend/access/transam/twophase.c
+++ b/src/backend/access/transam/twophase.c
@@ -2682,3 +2682,65 @@ LookupGXact(const char *gid, XLogRecPtr prepare_end_lsn,
LWLockRelease(TwoPhaseStateLock);
return found;
}
+
+/*
+ * TwoPhaseTransactionGid
+ * Form the prepared transaction GID for two_phase transactions.
+ *
+ * Return the GID in the supplied buffer.
+ */
+void
+TwoPhaseTransactionGid(Oid subid, TransactionId xid, char *gid, int szgid)
+{
+ Assert(subid != InvalidRepOriginId);
+
+ if (!TransactionIdIsValid(xid))
+ ereport(ERROR,
+ (errcode(ERRCODE_PROTOCOL_VIOLATION),
+ errmsg_internal("invalid two-phase transaction ID")));
+
+ snprintf(gid, szgid, "pg_gid_%u_%u", subid, xid);
+}
+
+/*
+ * IsTwoPhaseTransactionGidForSubid
+ * Check whether the given GID (as formed by TwoPhaseTransactionGid) is
+ * for the specified 'subid'.
+ */
+static bool
+IsTwoPhaseTransactionGidForSubid(Oid subid, char *gid)
+{
+ int ret;
+ Oid subid_written;
+ TransactionId xid;
+
+ ret = sscanf(gid, "pg_gid_%u_%u", &subid_written, &xid);
+
+ return (ret == 2 && subid == subid_written);
+}
+
+/*
+ * LookupGXactBySubid
+ * Check if the prepared transaction done by apply worker exists.
+ */
+bool
+LookupGXactBySubid(Oid subid)
+{
+ bool found = false;
+
+ LWLockAcquire(TwoPhaseStateLock, LW_SHARED);
+ for (int i = 0; i < TwoPhaseState->numPrepXacts; i++)
+ {
+ GlobalTransaction gxact = TwoPhaseState->prepXacts[i];
+
+ /* Ignore not-yet-valid GIDs. */
+ if (gxact->valid &&
+ IsTwoPhaseTransactionGidForSubid(subid, gxact->gid))
+ {
+ found = true;
+ break;
+ }
+ }
+ LWLockRelease(TwoPhaseStateLock);
+ return found;
+}
diff --git a/src/backend/commands/subscriptioncmds.c b/src/backend/commands/subscriptioncmds.c
index e407428dbc..90d967eb7c 100644
--- a/src/backend/commands/subscriptioncmds.c
+++ b/src/backend/commands/subscriptioncmds.c
@@ -16,6 +16,7 @@
#include "access/htup_details.h"
#include "access/table.h"
+#include "access/twophase.h"
#include "access/xact.h"
#include "catalog/catalog.h"
#include "catalog/dependency.h"
@@ -1143,7 +1144,8 @@ AlterSubscription(ParseState *pstate, AlterSubscriptionStmt *stmt,
{
supported_opts = (SUBOPT_SLOT_NAME |
SUBOPT_SYNCHRONOUS_COMMIT | SUBOPT_BINARY |
- SUBOPT_STREAMING | SUBOPT_DISABLE_ON_ERR |
+ SUBOPT_STREAMING | SUBOPT_TWOPHASE_COMMIT |
+ SUBOPT_DISABLE_ON_ERR |
SUBOPT_PASSWORD_REQUIRED |
SUBOPT_RUN_AS_OWNER | SUBOPT_FAILOVER |
SUBOPT_ORIGIN);
@@ -1151,6 +1153,52 @@ AlterSubscription(ParseState *pstate, AlterSubscriptionStmt *stmt,
parse_subscription_options(pstate, stmt->options,
supported_opts, &opts);
+ if (IsSet(opts.specified_opts, SUBOPT_TWOPHASE_COMMIT))
+ {
+ /*
+ * Do not allow changing the two_phase option if the
+ * subscription is enabled. This is because the two_phase
+ * option of the slot on the publisher cannot be modified
+ * if the slot is currently acquired by the apply worker.
+ */
+ if (form->subenabled)
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("cannot set %s for enabled subscription",
+ "two_phase")));
+
+ /*
+ * Stop all the subscription workers, just in case. Workers
+ * may still survive even if the subscription is disabled.
+ */
+ logicalrep_workers_stop(subid);
+
+ /*
+ * two_phase cannot be disabled if there are any
+ * uncommitted prepared transactions present.
+ */
+ if (!opts.twophase &&
+ form->subtwophasestate == LOGICALREP_TWOPHASE_STATE_ENABLED &&
+ LookupGXactBySubid(subid))
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("cannot disable two_phase when uncommitted prepared transactions present"),
+ errhint("Resolve these transactions and try again")));
+
+ /*
+ * The changed two_phase option of the slot can't be rolled
+ * back.
+ */
+ PreventInTransactionBlock(isTopLevel, "ALTER SUBSCRIPTION ... SET (two_phase)");
+
+ /* Change system catalog acoordingly */
+ values[Anum_pg_subscription_subtwophasestate - 1] =
+ CharGetDatum(opts.twophase ?
+ LOGICALREP_TWOPHASE_STATE_PENDING :
+ LOGICALREP_TWOPHASE_STATE_DISABLED);
+ replaces[Anum_pg_subscription_subtwophasestate - 1] = true;
+ }
+
if (IsSet(opts.specified_opts, SUBOPT_SLOT_NAME))
{
/*
@@ -1505,7 +1553,8 @@ AlterSubscription(ParseState *pstate, AlterSubscriptionStmt *stmt,
* doing the database operations we won't be able to rollback altered
* slot.
*/
- if (replaces[Anum_pg_subscription_subfailover - 1])
+ if (replaces[Anum_pg_subscription_subfailover - 1] ||
+ replaces[Anum_pg_subscription_subtwophasestate - 1])
{
bool must_use_password;
char *err;
@@ -1525,7 +1574,7 @@ AlterSubscription(ParseState *pstate, AlterSubscriptionStmt *stmt,
PG_TRY();
{
- walrcv_alter_slot(wrconn, sub->slotname, opts.failover);
+ walrcv_alter_slot(wrconn, sub->slotname, opts.failover, opts.twophase);
}
PG_FINALLY();
{
@@ -1562,7 +1611,6 @@ DropSubscription(DropSubscriptionStmt *stmt, bool isTopLevel)
char *subname;
char *conninfo;
char *slotname;
- List *subworkers;
ListCell *lc;
char originname[NAMEDATALEN];
char *err = NULL;
@@ -1672,16 +1720,7 @@ DropSubscription(DropSubscriptionStmt *stmt, bool isTopLevel)
* New workers won't be started because we hold an exclusive lock on the
* subscription till the end of the transaction.
*/
- LWLockAcquire(LogicalRepWorkerLock, LW_SHARED);
- subworkers = logicalrep_workers_find(subid, false);
- LWLockRelease(LogicalRepWorkerLock);
- foreach(lc, subworkers)
- {
- LogicalRepWorker *w = (LogicalRepWorker *) lfirst(lc);
-
- logicalrep_worker_stop(w->subid, w->relid);
- }
- list_free(subworkers);
+ logicalrep_workers_stop(subid);
/*
* Remove the no-longer-useful entry in the launcher's table of apply
diff --git a/src/backend/replication/libpqwalreceiver/libpqwalreceiver.c b/src/backend/replication/libpqwalreceiver/libpqwalreceiver.c
index 3c2b1bb496..998bbd517a 100644
--- a/src/backend/replication/libpqwalreceiver/libpqwalreceiver.c
+++ b/src/backend/replication/libpqwalreceiver/libpqwalreceiver.c
@@ -80,7 +80,7 @@ static char *libpqrcv_create_slot(WalReceiverConn *conn,
CRSSnapshotAction snapshot_action,
XLogRecPtr *lsn);
static void libpqrcv_alter_slot(WalReceiverConn *conn, const char *slotname,
- bool failover);
+ bool failover, bool two_phase);
static pid_t libpqrcv_get_backend_pid(WalReceiverConn *conn);
static WalRcvExecResult *libpqrcv_exec(WalReceiverConn *conn,
const char *query,
@@ -1121,15 +1121,16 @@ libpqrcv_create_slot(WalReceiverConn *conn, const char *slotname,
*/
static void
libpqrcv_alter_slot(WalReceiverConn *conn, const char *slotname,
- bool failover)
+ bool failover, bool two_phase)
{
StringInfoData cmd;
PGresult *res;
initStringInfo(&cmd);
- appendStringInfo(&cmd, "ALTER_REPLICATION_SLOT %s ( FAILOVER %s )",
+ appendStringInfo(&cmd, "ALTER_REPLICATION_SLOT %s ( FAILOVER %s, TWO_PHASE %s )",
quote_identifier(slotname),
- failover ? "true" : "false");
+ failover ? "true" : "false",
+ two_phase ? "true" : "false");
res = libpqrcv_PQexec(conn->streamConn, cmd.data);
pfree(cmd.data);
diff --git a/src/backend/replication/logical/launcher.c b/src/backend/replication/logical/launcher.c
index 66070e9131..548f6e0edb 100644
--- a/src/backend/replication/logical/launcher.c
+++ b/src/backend/replication/logical/launcher.c
@@ -623,6 +623,28 @@ logicalrep_worker_stop(Oid subid, Oid relid)
LWLockRelease(LogicalRepWorkerLock);
}
+/*
+ * Stop all the subscription workers.
+ */
+void
+logicalrep_workers_stop(Oid subid)
+{
+ List *subworkers;
+ ListCell *lc;
+
+ LWLockAcquire(LogicalRepWorkerLock, LW_SHARED);
+ /* XXX clarify the reason why not only running workers are listed. */
+ subworkers = logicalrep_workers_find(subid, false);
+ LWLockRelease(LogicalRepWorkerLock);
+ foreach(lc, subworkers)
+ {
+ LogicalRepWorker *w = (LogicalRepWorker *) lfirst(lc);
+
+ logicalrep_worker_stop(w->subid, w->relid);
+ }
+ list_free(subworkers);
+}
+
/*
* Stop the given logical replication parallel apply worker.
*
diff --git a/src/backend/replication/logical/worker.c b/src/backend/replication/logical/worker.c
index b5a80fe3e8..dcf656fd45 100644
--- a/src/backend/replication/logical/worker.c
+++ b/src/backend/replication/logical/worker.c
@@ -402,7 +402,6 @@ static void apply_handle_tuple_routing(ApplyExecutionData *edata,
CmdType operation);
/* Compute GID for two_phase transactions */
-static void TwoPhaseTransactionGid(Oid subid, TransactionId xid, char *gid, int szgid);
/* Functions for skipping changes */
static void maybe_start_skipping_changes(XLogRecPtr finish_lsn);
@@ -3911,7 +3910,7 @@ maybe_reread_subscription(void)
/* !slotname should never happen when enabled is true. */
Assert(newsub->slotname);
- /* two-phase should not be altered */
+ /* two-phase cannot be altered while the worker exists */
Assert(newsub->twophasestate == MySubscription->twophasestate);
/*
@@ -4396,24 +4395,6 @@ cleanup_subxact_info()
subxact_data.nsubxacts_max = 0;
}
-/*
- * Form the prepared transaction GID for two_phase transactions.
- *
- * Return the GID in the supplied buffer.
- */
-static void
-TwoPhaseTransactionGid(Oid subid, TransactionId xid, char *gid, int szgid)
-{
- Assert(subid != InvalidRepOriginId);
-
- if (!TransactionIdIsValid(xid))
- ereport(ERROR,
- (errcode(ERRCODE_PROTOCOL_VIOLATION),
- errmsg_internal("invalid two-phase transaction ID")));
-
- snprintf(gid, szgid, "pg_gid_%u_%u", subid, xid);
-}
-
/*
* Common function to run the apply loop with error handling. Disable the
* subscription, if necessary.
diff --git a/src/backend/replication/slot.c b/src/backend/replication/slot.c
index aa4ea387da..d0c8d5a4df 100644
--- a/src/backend/replication/slot.c
+++ b/src/backend/replication/slot.c
@@ -804,8 +804,10 @@ ReplicationSlotDrop(const char *name, bool nowait)
* Change the definition of the slot identified by the specified name.
*/
void
-ReplicationSlotAlter(const char *name, bool failover)
+ReplicationSlotAlter(const char *name, bool failover, bool two_phase)
{
+ bool update_slot = false;
+
Assert(MyReplicationSlot == NULL);
ReplicationSlotAcquire(name, false);
@@ -854,6 +856,20 @@ ReplicationSlotAlter(const char *name, bool failover)
MyReplicationSlot->data.failover = failover;
SpinLockRelease(&MyReplicationSlot->mutex);
+ update_slot = true;
+ }
+
+ if (MyReplicationSlot->data.two_phase != two_phase)
+ {
+ SpinLockAcquire(&MyReplicationSlot->mutex);
+ MyReplicationSlot->data.two_phase = two_phase;
+ SpinLockRelease(&MyReplicationSlot->mutex);
+
+ update_slot = true;
+ }
+
+ if (update_slot)
+ {
ReplicationSlotMarkDirty();
ReplicationSlotSave();
}
diff --git a/src/backend/replication/walsender.c b/src/backend/replication/walsender.c
index c623b07cf0..2e6ca35049 100644
--- a/src/backend/replication/walsender.c
+++ b/src/backend/replication/walsender.c
@@ -1411,9 +1411,11 @@ DropReplicationSlot(DropReplicationSlotCmd *cmd)
* Process extra options given to ALTER_REPLICATION_SLOT.
*/
static void
-ParseAlterReplSlotOptions(AlterReplicationSlotCmd *cmd, bool *failover)
+ParseAlterReplSlotOptions(AlterReplicationSlotCmd *cmd,
+ bool *failover, bool *two_phase)
{
bool failover_given = false;
+ bool two_phase_given = false;
/* Parse options */
foreach_ptr(DefElem, defel, cmd->options)
@@ -1427,6 +1429,15 @@ ParseAlterReplSlotOptions(AlterReplicationSlotCmd *cmd, bool *failover)
failover_given = true;
*failover = defGetBoolean(defel);
}
+ else if (strcmp(defel->defname, "two_phase") == 0)
+ {
+ if (two_phase_given)
+ ereport(ERROR,
+ (errcode(ERRCODE_SYNTAX_ERROR),
+ errmsg("conflicting or redundant options")));
+ two_phase_given = true;
+ *two_phase = defGetBoolean(defel);
+ }
else
elog(ERROR, "unrecognized option: %s", defel->defname);
}
@@ -1439,9 +1450,10 @@ static void
AlterReplicationSlot(AlterReplicationSlotCmd *cmd)
{
bool failover = false;
+ bool two_phase = false;
- ParseAlterReplSlotOptions(cmd, &failover);
- ReplicationSlotAlter(cmd->slotname, failover);
+ ParseAlterReplSlotOptions(cmd, &failover, &two_phase);
+ ReplicationSlotAlter(cmd->slotname, failover, two_phase);
}
/*
diff --git a/src/bin/psql/tab-complete.c b/src/bin/psql/tab-complete.c
index d453e224d9..891face1b6 100644
--- a/src/bin/psql/tab-complete.c
+++ b/src/bin/psql/tab-complete.c
@@ -1948,7 +1948,7 @@ psql_completion(const char *text, int start, int end)
else if (HeadMatches("ALTER", "SUBSCRIPTION", MatchAny) && TailMatches("SET", "("))
COMPLETE_WITH("binary", "disable_on_error", "failover", "origin",
"password_required", "run_as_owner", "slot_name",
- "streaming", "synchronous_commit");
+ "streaming", "synchronous_commit", "two_phase");
/* ALTER SUBSCRIPTION <name> SKIP ( */
else if (HeadMatches("ALTER", "SUBSCRIPTION", MatchAny) && TailMatches("SKIP", "("))
COMPLETE_WITH("lsn");
diff --git a/src/include/access/twophase.h b/src/include/access/twophase.h
index 56248c0006..d37e06fdee 100644
--- a/src/include/access/twophase.h
+++ b/src/include/access/twophase.h
@@ -62,4 +62,9 @@ extern void PrepareRedoRemove(TransactionId xid, bool giveWarning);
extern void restoreTwoPhaseData(void);
extern bool LookupGXact(const char *gid, XLogRecPtr prepare_end_lsn,
TimestampTz origin_prepare_timestamp);
+
+extern void TwoPhaseTransactionGid(Oid subid, TransactionId xid, char *gid,
+ int szgid);
+extern bool LookupGXactBySubid(Oid subid);
+
#endif /* TWOPHASE_H */
diff --git a/src/include/replication/slot.h b/src/include/replication/slot.h
index 1bc80960ef..014e216cf5 100644
--- a/src/include/replication/slot.h
+++ b/src/include/replication/slot.h
@@ -243,7 +243,8 @@ extern void ReplicationSlotCreate(const char *name, bool db_specific,
extern void ReplicationSlotPersist(void);
extern void ReplicationSlotDrop(const char *name, bool nowait);
extern void ReplicationSlotDropAcquired(void);
-extern void ReplicationSlotAlter(const char *name, bool failover);
+extern void ReplicationSlotAlter(const char *name, bool failover,
+ bool two_phase);
extern void ReplicationSlotAcquire(const char *name, bool nowait);
extern void ReplicationSlotRelease(void);
diff --git a/src/include/replication/walreceiver.h b/src/include/replication/walreceiver.h
index 12f71fa99b..31fa1257ec 100644
--- a/src/include/replication/walreceiver.h
+++ b/src/include/replication/walreceiver.h
@@ -372,12 +372,13 @@ typedef char *(*walrcv_create_slot_fn) (WalReceiverConn *conn,
/*
* walrcv_alter_slot_fn
*
- * Change the definition of a replication slot. Currently, it only supports
- * changing the failover property of the slot.
+ * Change the definition of a replication slot. Currently, it supports
+ * changing the failover and the two_phase property of the slot.
*/
typedef void (*walrcv_alter_slot_fn) (WalReceiverConn *conn,
const char *slotname,
- bool failover);
+ bool failover,
+ bool two_phase);
/*
* walrcv_get_backend_pid_fn
@@ -455,8 +456,8 @@ extern PGDLLIMPORT WalReceiverFunctionsType *WalReceiverFunctions;
WalReceiverFunctions->walrcv_send(conn, buffer, nbytes)
#define walrcv_create_slot(conn, slotname, temporary, two_phase, failover, snapshot_action, lsn) \
WalReceiverFunctions->walrcv_create_slot(conn, slotname, temporary, two_phase, failover, snapshot_action, lsn)
-#define walrcv_alter_slot(conn, slotname, failover) \
- WalReceiverFunctions->walrcv_alter_slot(conn, slotname, failover)
+#define walrcv_alter_slot(conn, slotname, failover, two_phase) \
+ WalReceiverFunctions->walrcv_alter_slot(conn, slotname, failover, two_phase)
#define walrcv_get_backend_pid(conn) \
WalReceiverFunctions->walrcv_get_backend_pid(conn)
#define walrcv_exec(conn, exec, nRetTypes, retTypes) \
diff --git a/src/include/replication/worker_internal.h b/src/include/replication/worker_internal.h
index 515aefd519..d5428263c1 100644
--- a/src/include/replication/worker_internal.h
+++ b/src/include/replication/worker_internal.h
@@ -246,6 +246,7 @@ extern bool logicalrep_worker_launch(LogicalRepWorkerType wtype,
Oid userid, Oid relid,
dsm_handle subworker_dsm);
extern void logicalrep_worker_stop(Oid subid, Oid relid);
+extern void logicalrep_workers_stop(Oid subid);
extern void logicalrep_pa_worker_stop(ParallelApplyWorkerInfo *winfo);
extern void logicalrep_worker_wakeup(Oid subid, Oid relid);
extern void logicalrep_worker_wakeup_ptr(LogicalRepWorker *worker);
diff --git a/src/test/regress/expected/subscription.out b/src/test/regress/expected/subscription.out
index 0f2a25cdc1..51fa4b9690 100644
--- a/src/test/regress/expected/subscription.out
+++ b/src/test/regress/expected/subscription.out
@@ -377,10 +377,7 @@ HINT: To initiate replication, you must manually create the replication slot, e
regress_testsub | regress_subscription_user | f | {testpub} | f | off | p | f | any | t | f | f | off | dbname=regress_doesnotexist | 0/0
(1 row)
---fail - alter of two_phase option not supported.
-ALTER SUBSCRIPTION regress_testsub SET (two_phase = false);
-ERROR: unrecognized subscription parameter: "two_phase"
--- but can alter streaming when two_phase enabled
+-- We can alter streaming when two_phase enabled
ALTER SUBSCRIPTION regress_testsub SET (streaming = true);
\dRs+
List of subscriptions
diff --git a/src/test/regress/sql/subscription.sql b/src/test/regress/sql/subscription.sql
index 3e5ba4cb8c..a3886d79ca 100644
--- a/src/test/regress/sql/subscription.sql
+++ b/src/test/regress/sql/subscription.sql
@@ -256,10 +256,7 @@ CREATE SUBSCRIPTION regress_testsub CONNECTION 'dbname=regress_doesnotexist' PUB
CREATE SUBSCRIPTION regress_testsub CONNECTION 'dbname=regress_doesnotexist' PUBLICATION testpub WITH (connect = false, two_phase = true);
\dRs+
---fail - alter of two_phase option not supported.
-ALTER SUBSCRIPTION regress_testsub SET (two_phase = false);
-
--- but can alter streaming when two_phase enabled
+-- We can alter streaming when two_phase enabled
ALTER SUBSCRIPTION regress_testsub SET (streaming = true);
\dRs+
diff --git a/src/test/subscription/t/021_twophase.pl b/src/test/subscription/t/021_twophase.pl
index 9437cd4c3b..72df258000 100644
--- a/src/test/subscription/t/021_twophase.pl
+++ b/src/test/subscription/t/021_twophase.pl
@@ -367,6 +367,75 @@ $result =
$node_subscriber->safe_psql('postgres', "SELECT count(*) FROM tab_copy;");
is($result, qq(2), 'replicated data in subscriber table');
+# Clean up
+$node_subscriber->safe_psql('postgres', "DROP SUBSCRIPTION tap_sub");
+
+###############################
+# Disable the subscription and alter it to two_phase = false,
+# then verify that the altered subscription reflects the two_phase option.
+###############################
+
+# Alter subscription two_phase to false
+$node_subscriber->safe_psql('postgres',
+ "ALTER SUBSCRIPTION tap_sub_copy DISABLE");
+$node_subscriber->safe_psql('postgres',
+ "ALTER SUBSCRIPTION tap_sub_copy SET (two_phase = false)");
+$node_subscriber->safe_psql('postgres',
+ "ALTER SUBSCRIPTION tap_sub_copy ENABLE");
+
+# Wait for subscription startup
+$node_subscriber->wait_for_subscription_sync($node_publisher, $appname_copy);
+
+# Make sure that the two-phase is disabled on the subscriber
+$result = $node_subscriber->safe_psql('postgres',
+ "SELECT subtwophasestate FROM pg_subscription WHERE subname = 'tap_sub_copy';"
+);
+is($result, qq(d), 'two-phase should be disabled');
+
+# Now do a prepare on the publisher and make sure that it is not replicated.
+$node_publisher->safe_psql(
+ 'postgres', qq{
+ BEGIN;
+ INSERT INTO tab_copy VALUES (100);
+ PREPARE TRANSACTION 'newgid';
+ });
+
+# Wait for the subscriber to catchup
+$node_publisher->wait_for_catchup($appname_copy);
+
+# Make sure there are no prepared transactions on the subscriber
+$result = $node_subscriber->safe_psql('postgres',
+ "SELECT count(*) FROM pg_prepared_xacts;");
+is($result, qq(0), 'should be no prepared transactions on subscriber');
+
+# Now commit the insert and verify that it IS replicated
+$node_publisher->safe_psql('postgres', "COMMIT PREPARED 'newgid';");
+
+# Wait for the subscriber to catchup
+$node_publisher->wait_for_catchup($appname_copy);
+
+# Make sure that the committed transaction is replicated.
+$result =
+ $node_subscriber->safe_psql('postgres', "SELECT count(*) FROM tab_copy;");
+is($result, qq(3), 'replicated data in subscriber table');
+
+# Alter subscription two_phase to true
+$node_subscriber->safe_psql('postgres',
+ "ALTER SUBSCRIPTION tap_sub_copy DISABLE");
+$node_subscriber->safe_psql('postgres',
+ "ALTER SUBSCRIPTION tap_sub_copy SET (two_phase = true)");
+$node_subscriber->safe_psql('postgres',
+ "ALTER SUBSCRIPTION tap_sub_copy ENABLE");
+
+# Wait for subscription startup
+$node_subscriber->wait_for_subscription_sync($node_publisher, $appname_copy);
+
+# Make sure that the two-phase is enabled on the subscriber
+$result = $node_subscriber->safe_psql('postgres',
+ "SELECT subtwophasestate FROM pg_subscription WHERE subname = 'tap_sub_copy';"
+);
+is($result, qq(e), 'two-phase should be enabled');
+
$node_subscriber->safe_psql('postgres', "DROP SUBSCRIPTION tap_sub_copy;");
$node_publisher->safe_psql('postgres', "DROP PUBLICATION tap_pub_copy;");
@@ -374,8 +443,6 @@ $node_publisher->safe_psql('postgres', "DROP PUBLICATION tap_pub_copy;");
# check all the cleanup
###############################
-$node_subscriber->safe_psql('postgres', "DROP SUBSCRIPTION tap_sub");
-
$result = $node_subscriber->safe_psql('postgres',
"SELECT count(*) FROM pg_subscription");
is($result, qq(0), 'check subscription was dropped on subscriber');
--
2.43.0
[application/octet-stream] v11-0002-Alter-slot-option-two_phase-only-when-altering-t.patch (12.3K, ../../OSBPR01MB25522052F9F3E3AAD3BA2A8CF5ED2@OSBPR01MB2552.jpnprd01.prod.outlook.com/3-v11-0002-Alter-slot-option-two_phase-only-when-altering-t.patch)
download | inline diff:
From c2e94d34ae70a07030bb549e6f29530ccee443ad Mon Sep 17 00:00:00 2001
From: Hayato Kuroda <[email protected]>
Date: Wed, 17 Apr 2024 06:18:23 +0000
Subject: [PATCH v11 2/4] Alter slot option two_phase only when altering "true"
to "false"
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit
Since the two_phase option is controlled by both the publisher (as a slot option)
and the subscriber (as a subscription option), the slot option must also be
modified.
Regarding the false->true case, the backend process alters the subtwophase to
LOGICALREP_TWOPHASE_STATE_PENDING once. After the subscription is enabled, a new
logical replication worker requests to change the two_phase option of its slot
from pending to true after the initial data synchronization is done. The code
path is the same as the case in which two_phase is initially set to true, so
there is no need to do something remarkable. However, for the true->false case,
the backend must connect to the publisher and expressly change the parameter
because the apply worker does not alter the option to false. Because this
operation cannot be rolled back, altering the two_phase parameter from "true"
to "false" within a transaction is prohibited.
---
doc/src/sgml/ref/alter_subscription.sgml | 2 +-
src/backend/commands/subscriptioncmds.c | 42 ++++++--
.../libpqwalreceiver/libpqwalreceiver.c | 23 +++--
src/include/replication/walreceiver.h | 5 +-
src/test/subscription/meson.build | 1 +
src/test/subscription/t/099_twophase_added.pl | 96 +++++++++++++++++++
6 files changed, 153 insertions(+), 16 deletions(-)
create mode 100644 src/test/subscription/t/099_twophase_added.pl
diff --git a/doc/src/sgml/ref/alter_subscription.sgml b/doc/src/sgml/ref/alter_subscription.sgml
index 88e9a72147..0c2894a94e 100644
--- a/doc/src/sgml/ref/alter_subscription.sgml
+++ b/doc/src/sgml/ref/alter_subscription.sgml
@@ -70,7 +70,7 @@ ALTER SUBSCRIPTION <replaceable class="parameter">name</replaceable> RENAME TO <
<command>ALTER SUBSCRIPTION ... {SET|ADD|DROP} PUBLICATION ...</command>
with <literal>refresh</literal> option as <literal>true</literal>,
<command>ALTER SUBSCRIPTION ... SET (failover = on|off)</command> and
- <command>ALTER SUBSCRIPTION ... SET (two_phase = on|off)</command>
+ <command>ALTER SUBSCRIPTION ... SET (two_phase = off)</command>
cannot be executed inside a transaction block.
These commands also cannot be executed when the subscription has
diff --git a/src/backend/commands/subscriptioncmds.c b/src/backend/commands/subscriptioncmds.c
index 90d967eb7c..ff733e3810 100644
--- a/src/backend/commands/subscriptioncmds.c
+++ b/src/backend/commands/subscriptioncmds.c
@@ -1097,6 +1097,8 @@ AlterSubscription(ParseState *pstate, AlterSubscriptionStmt *stmt,
Form_pg_subscription form;
bits32 supported_opts;
SubOpts opts = {0};
+ bool update_failover;
+ bool update_two_phase;
rel = table_open(SubscriptionRelationId, RowExclusiveLock);
@@ -1186,10 +1188,24 @@ AlterSubscription(ParseState *pstate, AlterSubscriptionStmt *stmt,
errhint("Resolve these transactions and try again")));
/*
- * The changed two_phase option of the slot can't be rolled
- * back.
+ * Altering the parameter from "true" to "false" within a
+ * transaction is prohibited. Since the apply worker does
+ * not alter the slot option to false, the backend must
+ * connect to the publisher and expressly change the
+ * parameter.
+ *
+ * There is no need to do something remarkable regarding
+ * the "false" to "true" case; the backend process alters
+ * subtwophase to LOGICALREP_TWOPHASE_STATE_PENDING once.
+ * After the subscription is enabled, a new logical
+ * replication worker requests to change the two_phase
+ * option of its slot from pending to true when the initial
+ * data synchronization is done. The code path is the same
+ * as the case in which two_phase is initially set to true.
*/
- PreventInTransactionBlock(isTopLevel, "ALTER SUBSCRIPTION ... SET (two_phase)");
+ if (!opts.twophase)
+ PreventInTransactionBlock(isTopLevel,
+ "ALTER SUBSCRIPTION ... SET (two_phase = false)");
/* Change system catalog acoordingly */
values[Anum_pg_subscription_subtwophasestate - 1] =
@@ -1547,14 +1563,24 @@ AlterSubscription(ParseState *pstate, AlterSubscriptionStmt *stmt,
}
/*
- * Try to acquire the connection necessary for altering slot.
+ * Check the need to alter the replication slot. Failover and two_phase
+ * options are controlled by both the publisher (as a slot option) and the
+ * subscriber (as a subscription option). The slot option must be altered
+ * only when changing "true" to "false". The reason has already been
+ * described in the ALTER_SUBSCRIPTION_OPTIONS section of this function.
+ */
+ update_failover = replaces[Anum_pg_subscription_subfailover - 1];
+ update_two_phase = (replaces[Anum_pg_subscription_subtwophasestate - 1] &&
+ !opts.twophase);
+
+ /*
+ * Try to acquire the connection necessary for altering slot, if needed.
*
* This has to be at the end because otherwise if there is an error while
* doing the database operations we won't be able to rollback altered
* slot.
*/
- if (replaces[Anum_pg_subscription_subfailover - 1] ||
- replaces[Anum_pg_subscription_subtwophasestate - 1])
+ if (update_failover || update_two_phase)
{
bool must_use_password;
char *err;
@@ -1574,7 +1600,9 @@ AlterSubscription(ParseState *pstate, AlterSubscriptionStmt *stmt,
PG_TRY();
{
- walrcv_alter_slot(wrconn, sub->slotname, opts.failover, opts.twophase);
+ walrcv_alter_slot(wrconn, sub->slotname,
+ update_failover ? &opts.failover : NULL,
+ update_two_phase ? &opts.twophase : NULL);
}
PG_FINALLY();
{
diff --git a/src/backend/replication/libpqwalreceiver/libpqwalreceiver.c b/src/backend/replication/libpqwalreceiver/libpqwalreceiver.c
index 998bbd517a..ff013aa987 100644
--- a/src/backend/replication/libpqwalreceiver/libpqwalreceiver.c
+++ b/src/backend/replication/libpqwalreceiver/libpqwalreceiver.c
@@ -80,7 +80,7 @@ static char *libpqrcv_create_slot(WalReceiverConn *conn,
CRSSnapshotAction snapshot_action,
XLogRecPtr *lsn);
static void libpqrcv_alter_slot(WalReceiverConn *conn, const char *slotname,
- bool failover, bool two_phase);
+ const bool *failover, const bool *two_phase);
static pid_t libpqrcv_get_backend_pid(WalReceiverConn *conn);
static WalRcvExecResult *libpqrcv_exec(WalReceiverConn *conn,
const char *query,
@@ -1121,16 +1121,27 @@ libpqrcv_create_slot(WalReceiverConn *conn, const char *slotname,
*/
static void
libpqrcv_alter_slot(WalReceiverConn *conn, const char *slotname,
- bool failover, bool two_phase)
+ const bool *failover, const bool *two_phase)
{
StringInfoData cmd;
PGresult *res;
initStringInfo(&cmd);
- appendStringInfo(&cmd, "ALTER_REPLICATION_SLOT %s ( FAILOVER %s, TWO_PHASE %s )",
- quote_identifier(slotname),
- failover ? "true" : "false",
- two_phase ? "true" : "false");
+ appendStringInfo(&cmd, "ALTER_REPLICATION_SLOT %s ( ",
+ quote_identifier(slotname));
+
+ if (failover)
+ appendStringInfo(&cmd, "FAILOVER %s",
+ *failover ? "true" : "false");
+
+ if (failover && two_phase)
+ appendStringInfo(&cmd, ", ");
+
+ if (two_phase)
+ appendStringInfo(&cmd, "TWO_PHASE %s",
+ *two_phase ? "true" : "false");
+
+ appendStringInfoString(&cmd, " );");
res = libpqrcv_PQexec(conn->streamConn, cmd.data);
pfree(cmd.data);
diff --git a/src/include/replication/walreceiver.h b/src/include/replication/walreceiver.h
index 31fa1257ec..7ffa5a58b3 100644
--- a/src/include/replication/walreceiver.h
+++ b/src/include/replication/walreceiver.h
@@ -377,8 +377,9 @@ typedef char *(*walrcv_create_slot_fn) (WalReceiverConn *conn,
*/
typedef void (*walrcv_alter_slot_fn) (WalReceiverConn *conn,
const char *slotname,
- bool failover,
- bool two_phase);
+ const bool *failover,
+ const bool *two_phase);
+
/*
* walrcv_get_backend_pid_fn
diff --git a/src/test/subscription/meson.build b/src/test/subscription/meson.build
index c591cd7d61..b4bd522c3d 100644
--- a/src/test/subscription/meson.build
+++ b/src/test/subscription/meson.build
@@ -40,6 +40,7 @@ tests += {
't/031_column_list.pl',
't/032_subscribe_use_index.pl',
't/033_run_as_table_owner.pl',
+ 't/099_twophase_added.pl',
't/100_bugs.pl',
],
},
diff --git a/src/test/subscription/t/099_twophase_added.pl b/src/test/subscription/t/099_twophase_added.pl
new file mode 100644
index 0000000000..ac08969b32
--- /dev/null
+++ b/src/test/subscription/t/099_twophase_added.pl
@@ -0,0 +1,96 @@
+# Copyright (c) 2024, PostgreSQL Global Development Group
+
+# Additional tests for altering two_phase option
+use strict;
+use warnings FATAL => 'all';
+use PostgreSQL::Test::Cluster;
+use PostgreSQL::Test::Utils;
+use Test::More;
+
+# Initialize publisher node
+my $node_publisher = PostgreSQL::Test::Cluster->new('publisher');
+$node_publisher->init(allows_streaming => 'logical');
+$node_publisher->append_conf('postgresql.conf',
+ qq(max_prepared_transactions = 10));
+$node_publisher->start;
+
+# Create subscriber node
+my $node_subscriber = PostgreSQL::Test::Cluster->new('subscriber');
+$node_subscriber->init;
+$node_subscriber->append_conf('postgresql.conf',
+ qq(max_prepared_transactions = 10
+ log_min_messages = debug1));
+$node_subscriber->start;
+
+# Define tables on both nodes
+$node_publisher->safe_psql('postgres',
+ "CREATE TABLE tab_full (a int PRIMARY KEY);");
+$node_subscriber->safe_psql('postgres',
+ "CREATE TABLE tab_full (a int PRIMARY KEY)");
+
+# Setup logical replication, with two_phase = "false"
+my $publisher_connstr = $node_publisher->connstr . ' dbname=postgres';
+$node_publisher->safe_psql('postgres',
+ "CREATE PUBLICATION pub FOR ALL TABLES");
+
+my $log_offset = -s $node_subscriber->logfile;
+
+$node_subscriber->safe_psql(
+ 'postgres', "
+ CREATE SUBSCRIPTION regress_sub
+ CONNECTION '$publisher_connstr' PUBLICATION pub
+ WITH (two_phase = false, copy_data = false, failover = false)");
+
+# Verify the started worker recognized two_phase was disabled
+$node_subscriber->wait_for_log(
+ 'logical replication apply worker for subscription "regress_sub" two_phase is DISABLED', $log_offset);
+
+#####################
+# Check the case that prepared transactions exist on the publisher node.
+#
+# Since the two_phase is "false", then normally, this PREPARE will do nothing
+# until the COMMIT PREPARED, but in this test, we toggle the two_phase to
+# "true" again before the COMMIT PREPARED happens.
+
+# Prepare a transaction to insert some tuples into the table
+$node_publisher->safe_psql(
+ 'postgres', "
+ BEGIN;
+ INSERT INTO tab_full VALUES (generate_series(1, 5));
+ PREPARE TRANSACTION 'test_prepared_tab_full';");
+
+$node_publisher->wait_for_catchup('regress_sub');
+
+# Verify the prepared transaction is not yet replicated to the subscriber
+# because two_phase is set to "false".
+my $result = $node_subscriber->safe_psql('postgres',
+ "SELECT count(*) FROM pg_prepared_xacts;");
+is($result, q(0), "transaction is not prepared on subscriber");
+
+$log_offset = -s $node_subscriber->logfile;
+
+# Toggle the two_phase to "true" *before* the COMMIT PREPARED. Since we are the
+# special path for the case where both two_phase and failover are altered, it
+# is also set to "true".
+$node_subscriber->safe_psql(
+ 'postgres', "
+ ALTER SUBSCRIPTION regress_sub DISABLE;
+ ALTER SUBSCRIPTION regress_sub SET (two_phase = true, failover = true);
+ ALTER SUBSCRIPTION regress_sub ENABLE;");
+
+# Verify the started worker recognized two_phase was enabled
+$node_subscriber->wait_for_log(
+ 'logical replication apply worker for subscription "regress_sub" two_phase is ENABLED', $log_offset);
+
+# And do COMMIT PREPARED the prepared transaction
+$node_publisher->safe_psql('postgres',
+ "COMMIT PREPARED 'test_prepared_tab_full';");
+$node_publisher->wait_for_catchup('regress_sub');
+
+# Verify inserted tuples are replicated
+$result = $node_subscriber->safe_psql('postgres',
+ "SELECT count(*) FROM tab_full;");
+is($result, q(5),
+ "prepared transactions done before altering can be replicated");
+
+done_testing();
--
2.43.0
[application/octet-stream] v11-0003-Abort-prepared-transactions-while-altering-two_p.patch (10.2K, ../../OSBPR01MB25522052F9F3E3AAD3BA2A8CF5ED2@OSBPR01MB2552.jpnprd01.prod.outlook.com/4-v11-0003-Abort-prepared-transactions-while-altering-two_p.patch)
download | inline diff:
From 25e0c246fe8d1f770b2b3255e6275cfc5600b98b Mon Sep 17 00:00:00 2001
From: Hayato Kuroda <[email protected]>
Date: Mon, 8 Apr 2024 12:39:12 +0000
Subject: [PATCH v11 3/4] Abort prepared transactions while altering two_phase
to off
If we alter the two_phase parameter from "on" to "off" and there are prepared
transactions on the subscriber, they won't be resolved. To avoid this issue, we
allow the backend to abort all prepared transactions while altering the
subscription.
---
doc/src/sgml/ref/alter_subscription.sgml | 11 ++-
src/backend/access/transam/twophase.c | 17 ++---
src/backend/commands/subscriptioncmds.c | 76 ++++++++++++-------
src/include/access/twophase.h | 3 +-
src/test/subscription/t/099_twophase_added.pl | 45 +++++++++++
5 files changed, 110 insertions(+), 42 deletions(-)
diff --git a/doc/src/sgml/ref/alter_subscription.sgml b/doc/src/sgml/ref/alter_subscription.sgml
index 0c2894a94e..2c6502275a 100644
--- a/doc/src/sgml/ref/alter_subscription.sgml
+++ b/doc/src/sgml/ref/alter_subscription.sgml
@@ -233,8 +233,6 @@ ALTER SUBSCRIPTION <replaceable class="parameter">name</replaceable> RENAME TO <
<link linkend="sql-createsubscription-params-with-failover"><literal>failover</literal></link>, and
<link linkend="sql-createsubscription-params-with-two-phase"><literal>two_phase</literal></link>.
Only a superuser can set <literal>password_required = false</literal>.
- The <literal>two_phase</literal> parameter can only be altered when the
- subscription is disabled.
</para>
<para>
@@ -256,6 +254,15 @@ ALTER SUBSCRIPTION <replaceable class="parameter">name</replaceable> RENAME TO <
<link linkend="sql-createsubscription-params-with-failover"><literal>failover</literal></link>
option is enabled.
</para>
+
+ <para>
+ The <literal>two_phase</literal> parameter can only be altered when the
+ subscription is disabled. When altering the parameter from <literal>true</literal>
+ to <literal>false</literal>, the backend process checks for any incomplete
+ prepared transactions done by the logical replication worker (from when
+ <literal>two_phase</literal> parameter was still <literal>true</literal>)
+ and, if any are found, those are aborted.
+ </para>
</listitem>
</varlistentry>
diff --git a/src/backend/access/transam/twophase.c b/src/backend/access/transam/twophase.c
index 66fa591eb5..f384bd8c0a 100644
--- a/src/backend/access/transam/twophase.c
+++ b/src/backend/access/transam/twophase.c
@@ -2720,13 +2720,13 @@ IsTwoPhaseTransactionGidForSubid(Oid subid, char *gid)
}
/*
- * LookupGXactBySubid
- * Check if the prepared transaction done by apply worker exists.
+ * GetGidListBySubid
+ * Get a list of GIDs which is PREPARE'd by the given subscription.
*/
-bool
-LookupGXactBySubid(Oid subid)
+List *
+GetGidListBySubid(Oid subid)
{
- bool found = false;
+ List *list = NIL;
LWLockAcquire(TwoPhaseStateLock, LW_SHARED);
for (int i = 0; i < TwoPhaseState->numPrepXacts; i++)
@@ -2736,11 +2736,8 @@ LookupGXactBySubid(Oid subid)
/* Ignore not-yet-valid GIDs. */
if (gxact->valid &&
IsTwoPhaseTransactionGidForSubid(subid, gxact->gid))
- {
- found = true;
- break;
- }
+ list = lappend(list, pstrdup(gxact->gid));
}
LWLockRelease(TwoPhaseStateLock);
- return found;
+ return list;
}
diff --git a/src/backend/commands/subscriptioncmds.c b/src/backend/commands/subscriptioncmds.c
index ff733e3810..82cad60547 100644
--- a/src/backend/commands/subscriptioncmds.c
+++ b/src/backend/commands/subscriptioncmds.c
@@ -1157,6 +1157,8 @@ AlterSubscription(ParseState *pstate, AlterSubscriptionStmt *stmt,
if (IsSet(opts.specified_opts, SUBOPT_TWOPHASE_COMMIT))
{
+ char subtwophase;
+
/*
* Do not allow changing the two_phase option if the
* subscription is enabled. This is because the two_phase
@@ -1176,42 +1178,58 @@ AlterSubscription(ParseState *pstate, AlterSubscriptionStmt *stmt,
logicalrep_workers_stop(subid);
/*
- * two_phase cannot be disabled if there are any
- * uncommitted prepared transactions present.
- */
- if (!opts.twophase &&
- form->subtwophasestate == LOGICALREP_TWOPHASE_STATE_ENABLED &&
- LookupGXactBySubid(subid))
- ereport(ERROR,
- (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
- errmsg("cannot disable two_phase when uncommitted prepared transactions present"),
- errhint("Resolve these transactions and try again")));
-
- /*
- * Altering the parameter from "true" to "false" within a
- * transaction is prohibited. Since the apply worker does
- * not alter the slot option to false, the backend must
- * connect to the publisher and expressly change the
- * parameter.
- *
- * There is no need to do something remarkable regarding
- * the "false" to "true" case; the backend process alters
- * subtwophase to LOGICALREP_TWOPHASE_STATE_PENDING once.
- * After the subscription is enabled, a new logical
- * replication worker requests to change the two_phase
- * option of its slot from pending to true when the initial
- * data synchronization is done. The code path is the same
- * as the case in which two_phase is initially set to true.
+ * If two_phase was previously enabled, there is a
+ * possibility that transactions have already been
+ * PREPARE'd. They must be checked and rolled back.
*/
if (!opts.twophase)
+ {
+ List *prepared_xacts;
+
+ /*
+ * Altering the parameter from "true" to "false" within
+ * a transaction is prohibited. Since the apply worker
+ * does not alter the slot option to false, the backend
+ * must connect to the publisher and expressly change
+ * the parameter.
+ *
+ * There is no need to do something remarkable
+ * regarding the "false" to "true" case; the backend
+ * process alters subtwophase to
+ * LOGICALREP_TWOPHASE_STATE_PENDING once. After the
+ * subscription is enabled, a new logical replication
+ * worker requests to change the two_phase option of
+ * its slot from pending to true when the initial data
+ * synchronization is done. The code path is the same
+ * as the case in which two_phase is initially set to
+ * true.
+ */
PreventInTransactionBlock(isTopLevel,
"ALTER SUBSCRIPTION ... SET (two_phase = false)");
+ /*
+ * To prevent prepared transactions from being
+ * isolated, they must manually be aborted.
+ */
+ if (sub->twophasestate == LOGICALREP_TWOPHASE_STATE_ENABLED &&
+ (prepared_xacts = GetGidListBySubid(subid)) != NIL)
+ {
+ /* Abort all listed transactions */
+ foreach_ptr(char, gid, prepared_xacts)
+ FinishPreparedTransaction(gid, false);
+
+ list_free_deep(prepared_xacts);
+ }
+
+ subtwophase = LOGICALREP_TWOPHASE_STATE_DISABLED;
+ }
+ else
+ subtwophase = LOGICALREP_TWOPHASE_STATE_PENDING;
+
+
/* Change system catalog acoordingly */
values[Anum_pg_subscription_subtwophasestate - 1] =
- CharGetDatum(opts.twophase ?
- LOGICALREP_TWOPHASE_STATE_PENDING :
- LOGICALREP_TWOPHASE_STATE_DISABLED);
+ CharGetDatum(subtwophase);
replaces[Anum_pg_subscription_subtwophasestate - 1] = true;
}
diff --git a/src/include/access/twophase.h b/src/include/access/twophase.h
index d37e06fdee..f7a5cf0c12 100644
--- a/src/include/access/twophase.h
+++ b/src/include/access/twophase.h
@@ -18,6 +18,7 @@
#include "access/xlogdefs.h"
#include "datatype/timestamp.h"
#include "storage/lock.h"
+#include "nodes/pg_list.h"
/*
* GlobalTransactionData is defined in twophase.c; other places have no
@@ -65,6 +66,6 @@ extern bool LookupGXact(const char *gid, XLogRecPtr prepare_end_lsn,
extern void TwoPhaseTransactionGid(Oid subid, TransactionId xid, char *gid,
int szgid);
-extern bool LookupGXactBySubid(Oid subid);
+extern List *GetGidListBySubid(Oid subid);
#endif /* TWOPHASE_H */
diff --git a/src/test/subscription/t/099_twophase_added.pl b/src/test/subscription/t/099_twophase_added.pl
index ac08969b32..5a9a6c6476 100644
--- a/src/test/subscription/t/099_twophase_added.pl
+++ b/src/test/subscription/t/099_twophase_added.pl
@@ -93,4 +93,49 @@ $result = $node_subscriber->safe_psql('postgres',
is($result, q(5),
"prepared transactions done before altering can be replicated");
+#####################
+# Check the case that prepared transactions exist on the subscriber node
+#
+# If the two_phase is altering from "true" to "false" and there are prepared
+# transactions on the subscriber, they must be aborted. This test checks it.
+
+# Prepare a transaction to insert some tuples into the table
+$node_publisher->safe_psql(
+ 'postgres', "
+ BEGIN;
+ INSERT INTO tab_full VALUES (generate_series(6, 10));
+ PREPARE TRANSACTION 'test_prepared_tab_full';");
+
+$node_publisher->wait_for_catchup('regress_sub');
+
+# Verify the prepared transaction has been replicated to the subscriber because
+# two_phase is set to "true".
+$result = $node_subscriber->safe_psql('postgres',
+ "SELECT count(*) FROM pg_prepared_xacts;");
+is($result, q(1), "transaction has been prepared on subscriber");
+
+# Toggle the two_phase to "false" before the COMMIT PREPARED
+$node_subscriber->safe_psql(
+ 'postgres', "
+ ALTER SUBSCRIPTION regress_sub DISABLE;
+ ALTER SUBSCRIPTION regress_sub SET (two_phase = false);
+ ALTER SUBSCRIPTION regress_sub ENABLE;");
+
+# Verify any prepared transactions are aborted because two_phase is changed to
+# "false".
+$result = $node_subscriber->safe_psql('postgres',
+ "SELECT count(*) FROM pg_prepared_xacts;");
+is($result, q(0), "prepared transaction done by worker is aborted");
+
+# Do COMMIT PREPARED the prepared transaction
+$node_publisher->safe_psql( 'postgres',
+ "COMMIT PREPARED 'test_prepared_tab_full';");
+$node_publisher->wait_for_catchup('regress_sub');
+
+# Verify inserted tuples are replicated
+$result = $node_subscriber->safe_psql('postgres',
+ "SELECT count(10) FROM tab_full;");
+is($result, q(10),
+ "prepared transactions on publisher can be replicated");
+
done_testing();
--
2.43.0
[application/octet-stream] v11-0004-Add-force_alter-option-for-ALTER-SUBSCRIPTION-.-.patch (56.9K, ../../OSBPR01MB25522052F9F3E3AAD3BA2A8CF5ED2@OSBPR01MB2552.jpnprd01.prod.outlook.com/5-v11-0004-Add-force_alter-option-for-ALTER-SUBSCRIPTION-.-.patch)
download | inline diff:
From e872bcaeedf4c203b5331ad9efb39945d89baa0d Mon Sep 17 00:00:00 2001
From: Hayato Kuroda <[email protected]>
Date: Fri, 19 Apr 2024 11:03:19 +0000
Subject: [PATCH v11 4/4] Add force_alter option for ALTER SUBSCRIPTION ... SET
command
Previously, all prepared transactions on the standby were rolled back when
toggling two_phase from "true" to "false". However, this operation may not be
expected by users. To ensure users understand what happens, we added the
"force_alter" parameter. When two_phase is toggling to "false", and there are
prepared transactions, they will be aborted only when "force_alter" is set to
true. Otherwise, an ERROR occurs.
---
doc/src/sgml/catalogs.sgml | 12 ++
doc/src/sgml/ref/alter_subscription.sgml | 16 +-
doc/src/sgml/ref/create_subscription.sgml | 24 +++
src/backend/catalog/pg_subscription.c | 1 +
src/backend/catalog/system_views.sql | 2 +-
src/backend/commands/subscriptioncmds.c | 36 ++++-
src/bin/pg_dump/pg_dump.c | 14 ++
src/bin/pg_dump/pg_dump.h | 1 +
src/bin/psql/describe.c | 7 +-
src/include/catalog/pg_subscription.h | 13 ++
src/test/regress/expected/subscription.out | 152 +++++++++---------
src/test/subscription/t/099_twophase_added.pl | 39 ++++-
12 files changed, 222 insertions(+), 95 deletions(-)
diff --git a/doc/src/sgml/catalogs.sgml b/doc/src/sgml/catalogs.sgml
index 5a6f65025b..8277475c25 100644
--- a/doc/src/sgml/catalogs.sgml
+++ b/doc/src/sgml/catalogs.sgml
@@ -8049,6 +8049,18 @@ SCRAM-SHA-256$<replaceable><iteration count></replaceable>:<replaceable>&l
</para></entry>
</row>
+ <row>
+ <entry role="catalog_table_entry"><para role="column_definition">
+ <structfield>subforcealter</structfield> <type>bool</type>
+ </para>
+ <para>
+ If true, then the <link linkend="sql-altersubscription"><command>ALTER SUBSCRIPTION</command></link>
+ can disable <literal>two_phase</literal> option, even if there are
+ uncommitted prepared transactions from when <literal>two_phase</literal>
+ was enabled
+ </para></entry>
+ </row>
+
<row>
<entry role="catalog_table_entry"><para role="column_definition">
<structfield>subconninfo</structfield> <type>text</type>
diff --git a/doc/src/sgml/ref/alter_subscription.sgml b/doc/src/sgml/ref/alter_subscription.sgml
index 2c6502275a..35513e7b33 100644
--- a/doc/src/sgml/ref/alter_subscription.sgml
+++ b/doc/src/sgml/ref/alter_subscription.sgml
@@ -230,8 +230,9 @@ ALTER SUBSCRIPTION <replaceable class="parameter">name</replaceable> RENAME TO <
<link linkend="sql-createsubscription-params-with-password-required"><literal>password_required</literal></link>,
<link linkend="sql-createsubscription-params-with-run-as-owner"><literal>run_as_owner</literal></link>,
<link linkend="sql-createsubscription-params-with-origin"><literal>origin</literal></link>,
- <link linkend="sql-createsubscription-params-with-failover"><literal>failover</literal></link>, and
- <link linkend="sql-createsubscription-params-with-two-phase"><literal>two_phase</literal></link>.
+ <link linkend="sql-createsubscription-params-with-failover"><literal>failover</literal></link>,
+ <link linkend="sql-createsubscription-params-with-two-phase"><literal>two_phase</literal></link>, and
+ <link linkend="sql-createsubscription-params-with-force-alter"><literal>force_alter</literal></link>
Only a superuser can set <literal>password_required = false</literal>.
</para>
@@ -257,11 +258,12 @@ ALTER SUBSCRIPTION <replaceable class="parameter">name</replaceable> RENAME TO <
<para>
The <literal>two_phase</literal> parameter can only be altered when the
- subscription is disabled. When altering the parameter from <literal>true</literal>
- to <literal>false</literal>, the backend process checks for any incomplete
- prepared transactions done by the logical replication worker (from when
- <literal>two_phase</literal> parameter was still <literal>true</literal>)
- and, if any are found, those are aborted.
+ subscription is disabled. Altering the parameter from <literal>true</literal>
+ to <literal>false</literal> will give an error when there are prepared
+ transactions done by the logical replication worker. If you want to alter
+ the parameter forcibly in this case,
+ <link linkend="sql-createsubscription-params-with-force-alter"><literal>force_alter</literal></link>
+ option must be set to <literal>true</literal>.
</para>
</listitem>
</varlistentry>
diff --git a/doc/src/sgml/ref/create_subscription.sgml b/doc/src/sgml/ref/create_subscription.sgml
index 740b7d9421..83ac52f865 100644
--- a/doc/src/sgml/ref/create_subscription.sgml
+++ b/doc/src/sgml/ref/create_subscription.sgml
@@ -428,6 +428,30 @@ CREATE SUBSCRIPTION <replaceable class="parameter">subscription_name</replaceabl
</para>
</listitem>
</varlistentry>
+
+ <varlistentry id="sql-createsubscription-params-with-force-alter">
+ <term><literal>force_alter</literal> (<type>boolean</type>)</term>
+ <listitem>
+ <para>
+ Specifies if the <link linkend="sql-altersubscription"><command>ALTER SUBSCRIPTION</command></link>
+ can be forced to proceed instead of giving an error.
+ </para>
+ <para>
+ There is currently only one scenario where this parameter has any
+ effect: When altering <literal>two_phase</literal> option from
+ <literal>true</literal> to <literal>false</literal> it is possible
+ for there to be incomplete prepared transactions done by the logical
+ replication worker (from when <literal>two_phase</literal> parameter
+ was still <literal>true</literal>). If <literal>force_alter</literal>
+ is <literal>false</literal>, then this will give an error; if
+ <literal>force_alter</literal> is <literal>true</literal>, then the
+ incomplete prepared transactions are aborted and the alter will proceed.
+ </para>
+ <para>
+ The default is <literal>false</literal>.
+ </para>
+ </listitem>
+ </varlistentry>
</variablelist></para>
</listitem>
diff --git a/src/backend/catalog/pg_subscription.c b/src/backend/catalog/pg_subscription.c
index 9efc9159f2..b568fe3470 100644
--- a/src/backend/catalog/pg_subscription.c
+++ b/src/backend/catalog/pg_subscription.c
@@ -72,6 +72,7 @@ GetSubscription(Oid subid, bool missing_ok)
sub->passwordrequired = subform->subpasswordrequired;
sub->runasowner = subform->subrunasowner;
sub->failover = subform->subfailover;
+ sub->forcealter = subform->subforcealter;
/* Get conninfo */
datum = SysCacheGetAttrNotNull(SUBSCRIPTIONOID,
diff --git a/src/backend/catalog/system_views.sql b/src/backend/catalog/system_views.sql
index 53047cab5f..de3d3d8f3e 100644
--- a/src/backend/catalog/system_views.sql
+++ b/src/backend/catalog/system_views.sql
@@ -1358,7 +1358,7 @@ REVOKE ALL ON pg_replication_origin_status FROM public;
REVOKE ALL ON pg_subscription FROM public;
GRANT SELECT (oid, subdbid, subskiplsn, subname, subowner, subenabled,
subbinary, substream, subtwophasestate, subdisableonerr,
- subpasswordrequired, subrunasowner, subfailover,
+ subpasswordrequired, subrunasowner, subfailover, subforcealter,
subslotname, subsynccommit, subpublications, suborigin)
ON pg_subscription TO public;
diff --git a/src/backend/commands/subscriptioncmds.c b/src/backend/commands/subscriptioncmds.c
index 82cad60547..778c59736f 100644
--- a/src/backend/commands/subscriptioncmds.c
+++ b/src/backend/commands/subscriptioncmds.c
@@ -73,6 +73,7 @@
#define SUBOPT_FAILOVER 0x00002000
#define SUBOPT_LSN 0x00004000
#define SUBOPT_ORIGIN 0x00008000
+#define SUBOPT_FORCE_ALTER 0x00010000
/* check if the 'val' has 'bits' set */
#define IsSet(val, bits) (((val) & (bits)) == (bits))
@@ -100,6 +101,7 @@ typedef struct SubOpts
bool failover;
char *origin;
XLogRecPtr lsn;
+ bool force_alter;
} SubOpts;
static List *fetch_table_list(WalReceiverConn *wrconn, List *publications);
@@ -162,6 +164,8 @@ parse_subscription_options(ParseState *pstate, List *stmt_options,
opts->failover = false;
if (IsSet(supported_opts, SUBOPT_ORIGIN))
opts->origin = pstrdup(LOGICALREP_ORIGIN_ANY);
+ if (IsSet(supported_opts, SUBOPT_FORCE_ALTER))
+ opts->force_alter = false;
/* Parse options */
foreach(lc, stmt_options)
@@ -367,6 +371,15 @@ parse_subscription_options(ParseState *pstate, List *stmt_options,
opts->specified_opts |= SUBOPT_LSN;
opts->lsn = lsn;
}
+ else if (IsSet(supported_opts, SUBOPT_FORCE_ALTER) &&
+ strcmp(defel->defname, "force_alter") == 0)
+ {
+ if (IsSet(opts->specified_opts, SUBOPT_FORCE_ALTER))
+ errorConflictingDefElem(defel, pstate);
+
+ opts->specified_opts |= SUBOPT_FORCE_ALTER;
+ opts->force_alter = defGetBoolean(defel);
+ }
else
ereport(ERROR,
(errcode(ERRCODE_SYNTAX_ERROR),
@@ -604,7 +617,8 @@ CreateSubscription(ParseState *pstate, CreateSubscriptionStmt *stmt,
SUBOPT_SYNCHRONOUS_COMMIT | SUBOPT_BINARY |
SUBOPT_STREAMING | SUBOPT_TWOPHASE_COMMIT |
SUBOPT_DISABLE_ON_ERR | SUBOPT_PASSWORD_REQUIRED |
- SUBOPT_RUN_AS_OWNER | SUBOPT_FAILOVER | SUBOPT_ORIGIN);
+ SUBOPT_RUN_AS_OWNER | SUBOPT_FAILOVER | SUBOPT_ORIGIN |
+ SUBOPT_FORCE_ALTER);
parse_subscription_options(pstate, stmt->options, supported_opts, &opts);
/*
@@ -711,6 +725,7 @@ CreateSubscription(ParseState *pstate, CreateSubscriptionStmt *stmt,
values[Anum_pg_subscription_subpasswordrequired - 1] = BoolGetDatum(opts.passwordrequired);
values[Anum_pg_subscription_subrunasowner - 1] = BoolGetDatum(opts.runasowner);
values[Anum_pg_subscription_subfailover - 1] = BoolGetDatum(opts.failover);
+ values[Anum_pg_subscription_subforcealter - 1] = BoolGetDatum(opts.force_alter);
values[Anum_pg_subscription_subconninfo - 1] =
CStringGetTextDatum(conninfo);
if (opts.slot_name)
@@ -1150,7 +1165,7 @@ AlterSubscription(ParseState *pstate, AlterSubscriptionStmt *stmt,
SUBOPT_DISABLE_ON_ERR |
SUBOPT_PASSWORD_REQUIRED |
SUBOPT_RUN_AS_OWNER | SUBOPT_FAILOVER |
- SUBOPT_ORIGIN);
+ SUBOPT_ORIGIN | SUBOPT_FORCE_ALTER);
parse_subscription_options(pstate, stmt->options,
supported_opts, &opts);
@@ -1214,6 +1229,23 @@ AlterSubscription(ParseState *pstate, AlterSubscriptionStmt *stmt,
if (sub->twophasestate == LOGICALREP_TWOPHASE_STATE_ENABLED &&
(prepared_xacts = GetGidListBySubid(subid)) != NIL)
{
+ bool raise_error =
+ IsSet(opts.specified_opts, SUBOPT_FORCE_ALTER) ?
+ !opts.force_alter : !sub->forcealter;
+
+ /*
+ * Abort prepared transactions only if
+ * 'force_alter' option is true. Otherwise raise
+ * an ERROR.
+ */
+ if (raise_error)
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("cannot alter %s when there are prepared transactions",
+ "two_phase = false"),
+ errhint("Resolve these transactions or set %s, and then try again.",
+ "force_alter = true")));
+
/* Abort all listed transactions */
foreach_ptr(char, gid, prepared_xacts)
FinishPreparedTransaction(gid, false);
diff --git a/src/bin/pg_dump/pg_dump.c b/src/bin/pg_dump/pg_dump.c
index 5dfa7b3bcb..da45392370 100644
--- a/src/bin/pg_dump/pg_dump.c
+++ b/src/bin/pg_dump/pg_dump.c
@@ -4739,6 +4739,7 @@ getSubscriptions(Archive *fout)
int i_suboriginremotelsn;
int i_subenabled;
int i_subfailover;
+ int i_subforcealter;
int i,
ntups;
@@ -4816,6 +4817,13 @@ getSubscriptions(Archive *fout)
appendPQExpBuffer(query,
" false AS subfailover\n");
+ if (fout->remoteVersion >= 170000)
+ appendPQExpBufferStr(query,
+ " s.subforcealter\n");
+ else
+ appendPQExpBuffer(query,
+ " false AS subforcealter\n");
+
appendPQExpBufferStr(query,
"FROM pg_subscription s\n");
@@ -4854,6 +4862,7 @@ getSubscriptions(Archive *fout)
i_suboriginremotelsn = PQfnumber(res, "suboriginremotelsn");
i_subenabled = PQfnumber(res, "subenabled");
i_subfailover = PQfnumber(res, "subfailover");
+ i_subforcealter = PQfnumber(res, "subforcealter");
subinfo = pg_malloc(ntups * sizeof(SubscriptionInfo));
@@ -4900,6 +4909,8 @@ getSubscriptions(Archive *fout)
pg_strdup(PQgetvalue(res, i, i_subenabled));
subinfo[i].subfailover =
pg_strdup(PQgetvalue(res, i, i_subfailover));
+ subinfo[i].subforcealter =
+ pg_strdup(PQgetvalue(res, i, i_subforcealter));
/* Decide whether we want to dump it */
selectDumpableObject(&(subinfo[i].dobj), fout);
@@ -5140,6 +5151,9 @@ dumpSubscription(Archive *fout, const SubscriptionInfo *subinfo)
if (strcmp(subinfo->subfailover, "t") == 0)
appendPQExpBufferStr(query, ", failover = true");
+ if (strcmp(subinfo->subforcealter, "t") == 0)
+ appendPQExpBufferStr(query, ", force_alter = true");
+
if (strcmp(subinfo->subsynccommit, "off") != 0)
appendPQExpBuffer(query, ", synchronous_commit = %s", fmtId(subinfo->subsynccommit));
diff --git a/src/bin/pg_dump/pg_dump.h b/src/bin/pg_dump/pg_dump.h
index f518a1e6d2..c666b9c113 100644
--- a/src/bin/pg_dump/pg_dump.h
+++ b/src/bin/pg_dump/pg_dump.h
@@ -672,6 +672,7 @@ typedef struct _SubscriptionInfo
char *suborigin;
char *suboriginremotelsn;
char *subfailover;
+ char *subforcealter;
} SubscriptionInfo;
/*
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index 3af44acef1..8e0a0b3b36 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -6537,7 +6537,7 @@ describeSubscriptions(const char *pattern, bool verbose)
printQueryOpt myopt = pset.popt;
static const bool translate_columns[] = {false, false, false, false,
false, false, false, false, false, false, false, false, false, false,
- false};
+ false, false};
if (pset.sversion < 100000)
{
@@ -6606,6 +6606,11 @@ describeSubscriptions(const char *pattern, bool verbose)
", subfailover AS \"%s\"\n",
gettext_noop("Failover"));
+ if (pset.sversion >= 170000)
+ appendPQExpBuffer(&buf,
+ ", subforcealter AS \"%s\"\n",
+ gettext_noop("Force alter"));
+
appendPQExpBuffer(&buf,
", subsynccommit AS \"%s\"\n"
", subconninfo AS \"%s\"\n",
diff --git a/src/include/catalog/pg_subscription.h b/src/include/catalog/pg_subscription.h
index 0aa14ec4a2..c23de43d79 100644
--- a/src/include/catalog/pg_subscription.h
+++ b/src/include/catalog/pg_subscription.h
@@ -98,6 +98,13 @@ CATALOG(pg_subscription,6100,SubscriptionRelationId) BKI_SHARED_RELATION BKI_ROW
* slots) in the upstream database are enabled
* to be synchronized to the standbys. */
+ bool subforcealter; /* True allows the ALTER SUBSCRIPTION command
+ * to proceed under conditions that would
+ * otherwise result in an error. Currently,
+ * 'force_alter' only has an effect when
+ * altering the two_phase option from "true" to
+ * "false". */
+
#ifdef CATALOG_VARLEN /* variable-length fields start here */
/* Connection string to the publisher */
text subconninfo BKI_FORCE_NOT_NULL;
@@ -151,6 +158,12 @@ typedef struct Subscription
* (i.e. the main slot and the table sync
* slots) in the upstream database are enabled
* to be synchronized to the standbys. */
+ bool forcealter; /* True allows the ALTER SUBSCRIPTION command
+ * to proceed under conditions that would
+ * otherwise result in an error. Currently,
+ * 'force_alter' only has an effect when
+ * altering the two_phase option from "true" to
+ * "false". */
char *conninfo; /* Connection string to the publisher */
char *slotname; /* Name of the replication slot */
char *synccommit; /* Synchronous commit setting for worker */
diff --git a/src/test/regress/expected/subscription.out b/src/test/regress/expected/subscription.out
index 51fa4b9690..b36fc6b8f7 100644
--- a/src/test/regress/expected/subscription.out
+++ b/src/test/regress/expected/subscription.out
@@ -116,18 +116,18 @@ CREATE SUBSCRIPTION regress_testsub4 CONNECTION 'dbname=regress_doesnotexist' PU
WARNING: subscription was created, but is not connected
HINT: To initiate replication, you must manually create the replication slot, enable the subscription, and refresh the subscription.
\dRs+ regress_testsub4
- List of subscriptions
- Name | Owner | Enabled | Publication | Binary | Streaming | Two-phase commit | Disable on error | Origin | Password required | Run as owner? | Failover | Synchronous commit | Conninfo | Skip LSN
-------------------+---------------------------+---------+-------------+--------+-----------+------------------+------------------+--------+-------------------+---------------+----------+--------------------+-----------------------------+----------
- regress_testsub4 | regress_subscription_user | f | {testpub} | f | off | d | f | none | t | f | f | off | dbname=regress_doesnotexist | 0/0
+ List of subscriptions
+ Name | Owner | Enabled | Publication | Binary | Streaming | Two-phase commit | Disable on error | Origin | Password required | Run as owner? | Failover | Force alter | Synchronous commit | Conninfo | Skip LSN
+------------------+---------------------------+---------+-------------+--------+-----------+------------------+------------------+--------+-------------------+---------------+----------+-------------+--------------------+-----------------------------+----------
+ regress_testsub4 | regress_subscription_user | f | {testpub} | f | off | d | f | none | t | f | f | f | off | dbname=regress_doesnotexist | 0/0
(1 row)
ALTER SUBSCRIPTION regress_testsub4 SET (origin = any);
\dRs+ regress_testsub4
- List of subscriptions
- Name | Owner | Enabled | Publication | Binary | Streaming | Two-phase commit | Disable on error | Origin | Password required | Run as owner? | Failover | Synchronous commit | Conninfo | Skip LSN
-------------------+---------------------------+---------+-------------+--------+-----------+------------------+------------------+--------+-------------------+---------------+----------+--------------------+-----------------------------+----------
- regress_testsub4 | regress_subscription_user | f | {testpub} | f | off | d | f | any | t | f | f | off | dbname=regress_doesnotexist | 0/0
+ List of subscriptions
+ Name | Owner | Enabled | Publication | Binary | Streaming | Two-phase commit | Disable on error | Origin | Password required | Run as owner? | Failover | Force alter | Synchronous commit | Conninfo | Skip LSN
+------------------+---------------------------+---------+-------------+--------+-----------+------------------+------------------+--------+-------------------+---------------+----------+-------------+--------------------+-----------------------------+----------
+ regress_testsub4 | regress_subscription_user | f | {testpub} | f | off | d | f | any | t | f | f | f | off | dbname=regress_doesnotexist | 0/0
(1 row)
DROP SUBSCRIPTION regress_testsub3;
@@ -145,10 +145,10 @@ ALTER SUBSCRIPTION regress_testsub CONNECTION 'foobar';
ERROR: invalid connection string syntax: missing "=" after "foobar" in connection info string
\dRs+
- List of subscriptions
- Name | Owner | Enabled | Publication | Binary | Streaming | Two-phase commit | Disable on error | Origin | Password required | Run as owner? | Failover | Synchronous commit | Conninfo | Skip LSN
------------------+---------------------------+---------+-------------+--------+-----------+------------------+------------------+--------+-------------------+---------------+----------+--------------------+-----------------------------+----------
- regress_testsub | regress_subscription_user | f | {testpub} | f | off | d | f | any | t | f | f | off | dbname=regress_doesnotexist | 0/0
+ List of subscriptions
+ Name | Owner | Enabled | Publication | Binary | Streaming | Two-phase commit | Disable on error | Origin | Password required | Run as owner? | Failover | Force alter | Synchronous commit | Conninfo | Skip LSN
+-----------------+---------------------------+---------+-------------+--------+-----------+------------------+------------------+--------+-------------------+---------------+----------+-------------+--------------------+-----------------------------+----------
+ regress_testsub | regress_subscription_user | f | {testpub} | f | off | d | f | any | t | f | f | f | off | dbname=regress_doesnotexist | 0/0
(1 row)
ALTER SUBSCRIPTION regress_testsub SET PUBLICATION testpub2, testpub3 WITH (refresh = false);
@@ -157,10 +157,10 @@ ALTER SUBSCRIPTION regress_testsub SET (slot_name = 'newname');
ALTER SUBSCRIPTION regress_testsub SET (password_required = false);
ALTER SUBSCRIPTION regress_testsub SET (run_as_owner = true);
\dRs+
- List of subscriptions
- Name | Owner | Enabled | Publication | Binary | Streaming | Two-phase commit | Disable on error | Origin | Password required | Run as owner? | Failover | Synchronous commit | Conninfo | Skip LSN
------------------+---------------------------+---------+---------------------+--------+-----------+------------------+------------------+--------+-------------------+---------------+----------+--------------------+------------------------------+----------
- regress_testsub | regress_subscription_user | f | {testpub2,testpub3} | f | off | d | f | any | f | t | f | off | dbname=regress_doesnotexist2 | 0/0
+ List of subscriptions
+ Name | Owner | Enabled | Publication | Binary | Streaming | Two-phase commit | Disable on error | Origin | Password required | Run as owner? | Failover | Force alter | Synchronous commit | Conninfo | Skip LSN
+-----------------+---------------------------+---------+---------------------+--------+-----------+------------------+------------------+--------+-------------------+---------------+----------+-------------+--------------------+------------------------------+----------
+ regress_testsub | regress_subscription_user | f | {testpub2,testpub3} | f | off | d | f | any | f | t | f | f | off | dbname=regress_doesnotexist2 | 0/0
(1 row)
ALTER SUBSCRIPTION regress_testsub SET (password_required = true);
@@ -176,10 +176,10 @@ ERROR: unrecognized subscription parameter: "create_slot"
-- ok
ALTER SUBSCRIPTION regress_testsub SKIP (lsn = '0/12345');
\dRs+
- List of subscriptions
- Name | Owner | Enabled | Publication | Binary | Streaming | Two-phase commit | Disable on error | Origin | Password required | Run as owner? | Failover | Synchronous commit | Conninfo | Skip LSN
------------------+---------------------------+---------+---------------------+--------+-----------+------------------+------------------+--------+-------------------+---------------+----------+--------------------+------------------------------+----------
- regress_testsub | regress_subscription_user | f | {testpub2,testpub3} | f | off | d | f | any | t | f | f | off | dbname=regress_doesnotexist2 | 0/12345
+ List of subscriptions
+ Name | Owner | Enabled | Publication | Binary | Streaming | Two-phase commit | Disable on error | Origin | Password required | Run as owner? | Failover | Force alter | Synchronous commit | Conninfo | Skip LSN
+-----------------+---------------------------+---------+---------------------+--------+-----------+------------------+------------------+--------+-------------------+---------------+----------+-------------+--------------------+------------------------------+----------
+ regress_testsub | regress_subscription_user | f | {testpub2,testpub3} | f | off | d | f | any | t | f | f | f | off | dbname=regress_doesnotexist2 | 0/12345
(1 row)
-- ok - with lsn = NONE
@@ -188,10 +188,10 @@ ALTER SUBSCRIPTION regress_testsub SKIP (lsn = NONE);
ALTER SUBSCRIPTION regress_testsub SKIP (lsn = '0/0');
ERROR: invalid WAL location (LSN): 0/0
\dRs+
- List of subscriptions
- Name | Owner | Enabled | Publication | Binary | Streaming | Two-phase commit | Disable on error | Origin | Password required | Run as owner? | Failover | Synchronous commit | Conninfo | Skip LSN
------------------+---------------------------+---------+---------------------+--------+-----------+------------------+------------------+--------+-------------------+---------------+----------+--------------------+------------------------------+----------
- regress_testsub | regress_subscription_user | f | {testpub2,testpub3} | f | off | d | f | any | t | f | f | off | dbname=regress_doesnotexist2 | 0/0
+ List of subscriptions
+ Name | Owner | Enabled | Publication | Binary | Streaming | Two-phase commit | Disable on error | Origin | Password required | Run as owner? | Failover | Force alter | Synchronous commit | Conninfo | Skip LSN
+-----------------+---------------------------+---------+---------------------+--------+-----------+------------------+------------------+--------+-------------------+---------------+----------+-------------+--------------------+------------------------------+----------
+ regress_testsub | regress_subscription_user | f | {testpub2,testpub3} | f | off | d | f | any | t | f | f | f | off | dbname=regress_doesnotexist2 | 0/0
(1 row)
BEGIN;
@@ -223,10 +223,10 @@ ALTER SUBSCRIPTION regress_testsub_foo SET (synchronous_commit = foobar);
ERROR: invalid value for parameter "synchronous_commit": "foobar"
HINT: Available values: local, remote_write, remote_apply, on, off.
\dRs+
- List of subscriptions
- Name | Owner | Enabled | Publication | Binary | Streaming | Two-phase commit | Disable on error | Origin | Password required | Run as owner? | Failover | Synchronous commit | Conninfo | Skip LSN
----------------------+---------------------------+---------+---------------------+--------+-----------+------------------+------------------+--------+-------------------+---------------+----------+--------------------+------------------------------+----------
- regress_testsub_foo | regress_subscription_user | f | {testpub2,testpub3} | f | off | d | f | any | t | f | f | local | dbname=regress_doesnotexist2 | 0/0
+ List of subscriptions
+ Name | Owner | Enabled | Publication | Binary | Streaming | Two-phase commit | Disable on error | Origin | Password required | Run as owner? | Failover | Force alter | Synchronous commit | Conninfo | Skip LSN
+---------------------+---------------------------+---------+---------------------+--------+-----------+------------------+------------------+--------+-------------------+---------------+----------+-------------+--------------------+------------------------------+----------
+ regress_testsub_foo | regress_subscription_user | f | {testpub2,testpub3} | f | off | d | f | any | t | f | f | f | local | dbname=regress_doesnotexist2 | 0/0
(1 row)
-- rename back to keep the rest simple
@@ -255,19 +255,19 @@ CREATE SUBSCRIPTION regress_testsub CONNECTION 'dbname=regress_doesnotexist' PUB
WARNING: subscription was created, but is not connected
HINT: To initiate replication, you must manually create the replication slot, enable the subscription, and refresh the subscription.
\dRs+
- List of subscriptions
- Name | Owner | Enabled | Publication | Binary | Streaming | Two-phase commit | Disable on error | Origin | Password required | Run as owner? | Failover | Synchronous commit | Conninfo | Skip LSN
------------------+---------------------------+---------+-------------+--------+-----------+------------------+------------------+--------+-------------------+---------------+----------+--------------------+-----------------------------+----------
- regress_testsub | regress_subscription_user | f | {testpub} | t | off | d | f | any | t | f | f | off | dbname=regress_doesnotexist | 0/0
+ List of subscriptions
+ Name | Owner | Enabled | Publication | Binary | Streaming | Two-phase commit | Disable on error | Origin | Password required | Run as owner? | Failover | Force alter | Synchronous commit | Conninfo | Skip LSN
+-----------------+---------------------------+---------+-------------+--------+-----------+------------------+------------------+--------+-------------------+---------------+----------+-------------+--------------------+-----------------------------+----------
+ regress_testsub | regress_subscription_user | f | {testpub} | t | off | d | f | any | t | f | f | f | off | dbname=regress_doesnotexist | 0/0
(1 row)
ALTER SUBSCRIPTION regress_testsub SET (binary = false);
ALTER SUBSCRIPTION regress_testsub SET (slot_name = NONE);
\dRs+
- List of subscriptions
- Name | Owner | Enabled | Publication | Binary | Streaming | Two-phase commit | Disable on error | Origin | Password required | Run as owner? | Failover | Synchronous commit | Conninfo | Skip LSN
------------------+---------------------------+---------+-------------+--------+-----------+------------------+------------------+--------+-------------------+---------------+----------+--------------------+-----------------------------+----------
- regress_testsub | regress_subscription_user | f | {testpub} | f | off | d | f | any | t | f | f | off | dbname=regress_doesnotexist | 0/0
+ List of subscriptions
+ Name | Owner | Enabled | Publication | Binary | Streaming | Two-phase commit | Disable on error | Origin | Password required | Run as owner? | Failover | Force alter | Synchronous commit | Conninfo | Skip LSN
+-----------------+---------------------------+---------+-------------+--------+-----------+------------------+------------------+--------+-------------------+---------------+----------+-------------+--------------------+-----------------------------+----------
+ regress_testsub | regress_subscription_user | f | {testpub} | f | off | d | f | any | t | f | f | f | off | dbname=regress_doesnotexist | 0/0
(1 row)
DROP SUBSCRIPTION regress_testsub;
@@ -279,27 +279,27 @@ CREATE SUBSCRIPTION regress_testsub CONNECTION 'dbname=regress_doesnotexist' PUB
WARNING: subscription was created, but is not connected
HINT: To initiate replication, you must manually create the replication slot, enable the subscription, and refresh the subscription.
\dRs+
- List of subscriptions
- Name | Owner | Enabled | Publication | Binary | Streaming | Two-phase commit | Disable on error | Origin | Password required | Run as owner? | Failover | Synchronous commit | Conninfo | Skip LSN
------------------+---------------------------+---------+-------------+--------+-----------+------------------+------------------+--------+-------------------+---------------+----------+--------------------+-----------------------------+----------
- regress_testsub | regress_subscription_user | f | {testpub} | f | on | d | f | any | t | f | f | off | dbname=regress_doesnotexist | 0/0
+ List of subscriptions
+ Name | Owner | Enabled | Publication | Binary | Streaming | Two-phase commit | Disable on error | Origin | Password required | Run as owner? | Failover | Force alter | Synchronous commit | Conninfo | Skip LSN
+-----------------+---------------------------+---------+-------------+--------+-----------+------------------+------------------+--------+-------------------+---------------+----------+-------------+--------------------+-----------------------------+----------
+ regress_testsub | regress_subscription_user | f | {testpub} | f | on | d | f | any | t | f | f | f | off | dbname=regress_doesnotexist | 0/0
(1 row)
ALTER SUBSCRIPTION regress_testsub SET (streaming = parallel);
\dRs+
- List of subscriptions
- Name | Owner | Enabled | Publication | Binary | Streaming | Two-phase commit | Disable on error | Origin | Password required | Run as owner? | Failover | Synchronous commit | Conninfo | Skip LSN
------------------+---------------------------+---------+-------------+--------+-----------+------------------+------------------+--------+-------------------+---------------+----------+--------------------+-----------------------------+----------
- regress_testsub | regress_subscription_user | f | {testpub} | f | parallel | d | f | any | t | f | f | off | dbname=regress_doesnotexist | 0/0
+ List of subscriptions
+ Name | Owner | Enabled | Publication | Binary | Streaming | Two-phase commit | Disable on error | Origin | Password required | Run as owner? | Failover | Force alter | Synchronous commit | Conninfo | Skip LSN
+-----------------+---------------------------+---------+-------------+--------+-----------+------------------+------------------+--------+-------------------+---------------+----------+-------------+--------------------+-----------------------------+----------
+ regress_testsub | regress_subscription_user | f | {testpub} | f | parallel | d | f | any | t | f | f | f | off | dbname=regress_doesnotexist | 0/0
(1 row)
ALTER SUBSCRIPTION regress_testsub SET (streaming = false);
ALTER SUBSCRIPTION regress_testsub SET (slot_name = NONE);
\dRs+
- List of subscriptions
- Name | Owner | Enabled | Publication | Binary | Streaming | Two-phase commit | Disable on error | Origin | Password required | Run as owner? | Failover | Synchronous commit | Conninfo | Skip LSN
------------------+---------------------------+---------+-------------+--------+-----------+------------------+------------------+--------+-------------------+---------------+----------+--------------------+-----------------------------+----------
- regress_testsub | regress_subscription_user | f | {testpub} | f | off | d | f | any | t | f | f | off | dbname=regress_doesnotexist | 0/0
+ List of subscriptions
+ Name | Owner | Enabled | Publication | Binary | Streaming | Two-phase commit | Disable on error | Origin | Password required | Run as owner? | Failover | Force alter | Synchronous commit | Conninfo | Skip LSN
+-----------------+---------------------------+---------+-------------+--------+-----------+------------------+------------------+--------+-------------------+---------------+----------+-------------+--------------------+-----------------------------+----------
+ regress_testsub | regress_subscription_user | f | {testpub} | f | off | d | f | any | t | f | f | f | off | dbname=regress_doesnotexist | 0/0
(1 row)
-- fail - publication already exists
@@ -314,10 +314,10 @@ ALTER SUBSCRIPTION regress_testsub ADD PUBLICATION testpub1, testpub2 WITH (refr
ALTER SUBSCRIPTION regress_testsub ADD PUBLICATION testpub1, testpub2 WITH (refresh = false);
ERROR: publication "testpub1" is already in subscription "regress_testsub"
\dRs+
- List of subscriptions
- Name | Owner | Enabled | Publication | Binary | Streaming | Two-phase commit | Disable on error | Origin | Password required | Run as owner? | Failover | Synchronous commit | Conninfo | Skip LSN
------------------+---------------------------+---------+-----------------------------+--------+-----------+------------------+------------------+--------+-------------------+---------------+----------+--------------------+-----------------------------+----------
- regress_testsub | regress_subscription_user | f | {testpub,testpub1,testpub2} | f | off | d | f | any | t | f | f | off | dbname=regress_doesnotexist | 0/0
+ List of subscriptions
+ Name | Owner | Enabled | Publication | Binary | Streaming | Two-phase commit | Disable on error | Origin | Password required | Run as owner? | Failover | Force alter | Synchronous commit | Conninfo | Skip LSN
+-----------------+---------------------------+---------+-----------------------------+--------+-----------+------------------+------------------+--------+-------------------+---------------+----------+-------------+--------------------+-----------------------------+----------
+ regress_testsub | regress_subscription_user | f | {testpub,testpub1,testpub2} | f | off | d | f | any | t | f | f | f | off | dbname=regress_doesnotexist | 0/0
(1 row)
-- fail - publication used more than once
@@ -332,10 +332,10 @@ ERROR: publication "testpub3" is not in subscription "regress_testsub"
-- ok - delete publications
ALTER SUBSCRIPTION regress_testsub DROP PUBLICATION testpub1, testpub2 WITH (refresh = false);
\dRs+
- List of subscriptions
- Name | Owner | Enabled | Publication | Binary | Streaming | Two-phase commit | Disable on error | Origin | Password required | Run as owner? | Failover | Synchronous commit | Conninfo | Skip LSN
------------------+---------------------------+---------+-------------+--------+-----------+------------------+------------------+--------+-------------------+---------------+----------+--------------------+-----------------------------+----------
- regress_testsub | regress_subscription_user | f | {testpub} | f | off | d | f | any | t | f | f | off | dbname=regress_doesnotexist | 0/0
+ List of subscriptions
+ Name | Owner | Enabled | Publication | Binary | Streaming | Two-phase commit | Disable on error | Origin | Password required | Run as owner? | Failover | Force alter | Synchronous commit | Conninfo | Skip LSN
+-----------------+---------------------------+---------+-------------+--------+-----------+------------------+------------------+--------+-------------------+---------------+----------+-------------+--------------------+-----------------------------+----------
+ regress_testsub | regress_subscription_user | f | {testpub} | f | off | d | f | any | t | f | f | f | off | dbname=regress_doesnotexist | 0/0
(1 row)
DROP SUBSCRIPTION regress_testsub;
@@ -371,19 +371,19 @@ CREATE SUBSCRIPTION regress_testsub CONNECTION 'dbname=regress_doesnotexist' PUB
WARNING: subscription was created, but is not connected
HINT: To initiate replication, you must manually create the replication slot, enable the subscription, and refresh the subscription.
\dRs+
- List of subscriptions
- Name | Owner | Enabled | Publication | Binary | Streaming | Two-phase commit | Disable on error | Origin | Password required | Run as owner? | Failover | Synchronous commit | Conninfo | Skip LSN
------------------+---------------------------+---------+-------------+--------+-----------+------------------+------------------+--------+-------------------+---------------+----------+--------------------+-----------------------------+----------
- regress_testsub | regress_subscription_user | f | {testpub} | f | off | p | f | any | t | f | f | off | dbname=regress_doesnotexist | 0/0
+ List of subscriptions
+ Name | Owner | Enabled | Publication | Binary | Streaming | Two-phase commit | Disable on error | Origin | Password required | Run as owner? | Failover | Force alter | Synchronous commit | Conninfo | Skip LSN
+-----------------+---------------------------+---------+-------------+--------+-----------+------------------+------------------+--------+-------------------+---------------+----------+-------------+--------------------+-----------------------------+----------
+ regress_testsub | regress_subscription_user | f | {testpub} | f | off | p | f | any | t | f | f | f | off | dbname=regress_doesnotexist | 0/0
(1 row)
-- We can alter streaming when two_phase enabled
ALTER SUBSCRIPTION regress_testsub SET (streaming = true);
\dRs+
- List of subscriptions
- Name | Owner | Enabled | Publication | Binary | Streaming | Two-phase commit | Disable on error | Origin | Password required | Run as owner? | Failover | Synchronous commit | Conninfo | Skip LSN
------------------+---------------------------+---------+-------------+--------+-----------+------------------+------------------+--------+-------------------+---------------+----------+--------------------+-----------------------------+----------
- regress_testsub | regress_subscription_user | f | {testpub} | f | on | p | f | any | t | f | f | off | dbname=regress_doesnotexist | 0/0
+ List of subscriptions
+ Name | Owner | Enabled | Publication | Binary | Streaming | Two-phase commit | Disable on error | Origin | Password required | Run as owner? | Failover | Force alter | Synchronous commit | Conninfo | Skip LSN
+-----------------+---------------------------+---------+-------------+--------+-----------+------------------+------------------+--------+-------------------+---------------+----------+-------------+--------------------+-----------------------------+----------
+ regress_testsub | regress_subscription_user | f | {testpub} | f | on | p | f | any | t | f | f | f | off | dbname=regress_doesnotexist | 0/0
(1 row)
ALTER SUBSCRIPTION regress_testsub SET (slot_name = NONE);
@@ -393,10 +393,10 @@ CREATE SUBSCRIPTION regress_testsub CONNECTION 'dbname=regress_doesnotexist' PUB
WARNING: subscription was created, but is not connected
HINT: To initiate replication, you must manually create the replication slot, enable the subscription, and refresh the subscription.
\dRs+
- List of subscriptions
- Name | Owner | Enabled | Publication | Binary | Streaming | Two-phase commit | Disable on error | Origin | Password required | Run as owner? | Failover | Synchronous commit | Conninfo | Skip LSN
------------------+---------------------------+---------+-------------+--------+-----------+------------------+------------------+--------+-------------------+---------------+----------+--------------------+-----------------------------+----------
- regress_testsub | regress_subscription_user | f | {testpub} | f | on | p | f | any | t | f | f | off | dbname=regress_doesnotexist | 0/0
+ List of subscriptions
+ Name | Owner | Enabled | Publication | Binary | Streaming | Two-phase commit | Disable on error | Origin | Password required | Run as owner? | Failover | Force alter | Synchronous commit | Conninfo | Skip LSN
+-----------------+---------------------------+---------+-------------+--------+-----------+------------------+------------------+--------+-------------------+---------------+----------+-------------+--------------------+-----------------------------+----------
+ regress_testsub | regress_subscription_user | f | {testpub} | f | on | p | f | any | t | f | f | f | off | dbname=regress_doesnotexist | 0/0
(1 row)
ALTER SUBSCRIPTION regress_testsub SET (slot_name = NONE);
@@ -409,18 +409,18 @@ CREATE SUBSCRIPTION regress_testsub CONNECTION 'dbname=regress_doesnotexist' PUB
WARNING: subscription was created, but is not connected
HINT: To initiate replication, you must manually create the replication slot, enable the subscription, and refresh the subscription.
\dRs+
- List of subscriptions
- Name | Owner | Enabled | Publication | Binary | Streaming | Two-phase commit | Disable on error | Origin | Password required | Run as owner? | Failover | Synchronous commit | Conninfo | Skip LSN
------------------+---------------------------+---------+-------------+--------+-----------+------------------+------------------+--------+-------------------+---------------+----------+--------------------+-----------------------------+----------
- regress_testsub | regress_subscription_user | f | {testpub} | f | off | d | f | any | t | f | f | off | dbname=regress_doesnotexist | 0/0
+ List of subscriptions
+ Name | Owner | Enabled | Publication | Binary | Streaming | Two-phase commit | Disable on error | Origin | Password required | Run as owner? | Failover | Force alter | Synchronous commit | Conninfo | Skip LSN
+-----------------+---------------------------+---------+-------------+--------+-----------+------------------+------------------+--------+-------------------+---------------+----------+-------------+--------------------+-----------------------------+----------
+ regress_testsub | regress_subscription_user | f | {testpub} | f | off | d | f | any | t | f | f | f | off | dbname=regress_doesnotexist | 0/0
(1 row)
ALTER SUBSCRIPTION regress_testsub SET (disable_on_error = true);
\dRs+
- List of subscriptions
- Name | Owner | Enabled | Publication | Binary | Streaming | Two-phase commit | Disable on error | Origin | Password required | Run as owner? | Failover | Synchronous commit | Conninfo | Skip LSN
------------------+---------------------------+---------+-------------+--------+-----------+------------------+------------------+--------+-------------------+---------------+----------+--------------------+-----------------------------+----------
- regress_testsub | regress_subscription_user | f | {testpub} | f | off | d | t | any | t | f | f | off | dbname=regress_doesnotexist | 0/0
+ List of subscriptions
+ Name | Owner | Enabled | Publication | Binary | Streaming | Two-phase commit | Disable on error | Origin | Password required | Run as owner? | Failover | Force alter | Synchronous commit | Conninfo | Skip LSN
+-----------------+---------------------------+---------+-------------+--------+-----------+------------------+------------------+--------+-------------------+---------------+----------+-------------+--------------------+-----------------------------+----------
+ regress_testsub | regress_subscription_user | f | {testpub} | f | off | d | t | any | t | f | f | f | off | dbname=regress_doesnotexist | 0/0
(1 row)
ALTER SUBSCRIPTION regress_testsub SET (slot_name = NONE);
diff --git a/src/test/subscription/t/099_twophase_added.pl b/src/test/subscription/t/099_twophase_added.pl
index 5a9a6c6476..662ecf308b 100644
--- a/src/test/subscription/t/099_twophase_added.pl
+++ b/src/test/subscription/t/099_twophase_added.pl
@@ -114,15 +114,38 @@ $result = $node_subscriber->safe_psql('postgres',
"SELECT count(*) FROM pg_prepared_xacts;");
is($result, q(1), "transaction has been prepared on subscriber");
-# Toggle the two_phase to "false" before the COMMIT PREPARED
-$node_subscriber->safe_psql(
- 'postgres', "
- ALTER SUBSCRIPTION regress_sub DISABLE;
- ALTER SUBSCRIPTION regress_sub SET (two_phase = false);
- ALTER SUBSCRIPTION regress_sub ENABLE;");
+# Disable the subscription to alter the two_phase option
+$node_subscriber->safe_psql('postgres', "ALTER SUBSCRIPTION regress_sub DISABLE;");
+
+# Try altering the two_phase option to "false". The command will fail since
+# there is a prepared transaction and the 'force_alter' option is not specified
+# as true.
+my $stdout;
+my $stderr;
+
+($result, $stdout, $stderr) = $node_subscriber->psql(
+ 'postgres', "ALTER SUBSCRIPTION regress_sub SET (two_phase = false);");
+ok($stderr =~ /cannot alter two_phase = false when there are prepared transactions/,
+ 'ALTER SUBSCRIPTION failed');
+
+# Verify the prepared transaction still exists
+$result = $node_subscriber->safe_psql('postgres',
+ "SELECT count(*) FROM pg_prepared_xacts;");
+is($result, q(1), "prepared transaction still exists");
+
+$log_offset = -s $node_subscriber->logfile;
+
+# Alter the two_phase true to false with the force_alter option enabled. This
+# command will succeed after aborting the prepared transaction.
+$node_subscriber->safe_psql('postgres',
+ "ALTER SUBSCRIPTION regress_sub SET (two_phase = false, force_alter = true);");
+$node_subscriber->safe_psql('postgres', "ALTER SUBSCRIPTION regress_sub ENABLE;");
+
+# Verify the started worker recognized two_phase was disabled
+$node_subscriber->wait_for_log(
+ 'logical replication apply worker for subscription "regress_sub" two_phase is DISABLED', $log_offset);
-# Verify any prepared transactions are aborted because two_phase is changed to
-# "false".
+# # Verify the prepared transaction was aborted
$result = $node_subscriber->safe_psql('postgres',
"SELECT count(*) FROM pg_prepared_xacts;");
is($result, q(0), "prepared transaction done by worker is aborted");
--
2.43.0
^ permalink raw reply [nested|flat] 25+ messages in thread
* RE: Slow catchup of 2PC (twophase) transactions on replica in LR
@ 2024-05-16 05:04 Hayato Kuroda (Fujitsu) <[email protected]>
parent: Peter Smith <[email protected]>
0 siblings, 0 replies; 25+ messages in thread
From: Hayato Kuroda (Fujitsu) @ 2024-05-16 05:04 UTC (permalink / raw)
To: 'Peter Smith' <[email protected]>; +Cc: [email protected] <[email protected]>; Amit Kapila <[email protected]>; Ajin Cherian <[email protected]>; Давыдов Виталий <[email protected]>
Dear Peter,
> You wrote "Fixed" for that patch v9-0004 suggestion but I don't think
> anything was changed at all. Accidentally missed?
Sorry, I missed to do `git add` after the revision.
The change was also included in new patch [1].
[1]: https://www.postgresql.org/message-id/OSBPR01MB25522052F9F3E3AAD3BA2A8CF5ED2%40OSBPR01MB2552.jpnprd0...
Best Regards,
Hayato Kuroda
FUJITSU LIMITED
https://www.fujitsu.com/
^ permalink raw reply [nested|flat] 25+ messages in thread
* Re: Slow catchup of 2PC (twophase) transactions on replica in LR
@ 2024-05-17 02:20 Peter Smith <[email protected]>
parent: Hayato Kuroda (Fujitsu) <[email protected]>
0 siblings, 0 replies; 25+ messages in thread
From: Peter Smith @ 2024-05-17 02:20 UTC (permalink / raw)
To: Hayato Kuroda (Fujitsu) <[email protected]>; +Cc: [email protected] <[email protected]>; Amit Kapila <[email protected]>; Ajin Cherian <[email protected]>; Давыдов Виталий <[email protected]>
Hi, Here are my remaining review comments for the latest v11* patches.
//////////
v11-0001
//////////
No changes. No comments.
//////////
v11-0002
//////////
======
doc/src/sgml/ref/alter_subscription.sgml
2.1.
<command>ALTER SUBSCRIPTION ... SET (failover = on|off)</command> and
- <command>ALTER SUBSCRIPTION ... SET (two_phase = on|off)</command>
+ <command>ALTER SUBSCRIPTION ... SET (two_phase = off)</command>
My other thread patch has already been pushed [1], so now you can
modify this to say "true|false" as previously suggested.
//////////
v11-0003
//////////
======
src/backend/commands/subscriptioncmds.c
3.1. AlterSubscription
+ subtwophase = LOGICALREP_TWOPHASE_STATE_DISABLED;
+ }
+ else
+ subtwophase = LOGICALREP_TWOPHASE_STATE_PENDING;
+
+
/* Change system catalog acoordingly */
values[Anum_pg_subscription_subtwophasestate - 1] =
- CharGetDatum(opts.twophase ?
- LOGICALREP_TWOPHASE_STATE_PENDING :
- LOGICALREP_TWOPHASE_STATE_DISABLED);
+ CharGetDatum(subtwophase);
replaces[Anum_pg_subscription_subtwophasestate - 1] = true;
Sorry, I don't think that 'subtwophase' change is an improvement --
IMO the existing ternary code was fine as-is.
I only reported the excessive flag checking in the previous v10-0003
review because of some extra "if (!opts.twophase)" code but that was
caused by what you called "wrong git operations." and is already fixed
now.
//////////
v11-0004
//////////
======
src/sgml/catalogs.sgml
4.1.
+ <row>
+ <entry role="catalog_table_entry"><para role="column_definition">
+ <structfield>subforcealter</structfield> <type>bool</type>
+ </para>
+ <para>
+ If true, then the <link
linkend="sql-altersubscription"><command>ALTER
SUBSCRIPTION</command></link>
+ can disable <literal>two_phase</literal> option, even if there are
+ uncommitted prepared transactions from when <literal>two_phase</literal>
+ was enabled
+ </para></entry>
+ </row>
+
I think this description should be changed to say what it *really*
does. IMO, the stuff about 'two_phase' is more like a side-effect.
SUGGESTION (this is just pseudo-code. You can add the CREATE
SUBSCRIPTION 'force_alter' link appropriately)
If true, then the <command>ALTER SUBSCRIPTION</command> command can
sometimes be forced to proceed instead of giving an error. See
<link>force_alter</link> parameter for details about when this might
be useful.
======
[1] https://github.com/postgres/postgres/commit/fa65a022db26bc446fb67ce1d7ac543fa4bb72e4
Kind Regards,
Peter Smith.
Fujitsu Australia
^ permalink raw reply [nested|flat] 25+ messages in thread
end of thread, other threads:[~2024-05-17 02:20 UTC | newest]
Thread overview: 25+ messages (download: mbox mbox.gz follow: Atom feed)
-- links below jump to the message on this page --
2024-03-18 08:34 [PATCH v3] Add "Backpatch" regions in wait_event_names.txt Bertrand Drouvot <[email protected]>
2024-05-08 00:07 Re: Slow catchup of 2PC (twophase) transactions on replica in LR Peter Smith <[email protected]>
2024-05-08 08:26 ` RE: Slow catchup of 2PC (twophase) transactions on replica in LR Hayato Kuroda (Fujitsu) <[email protected]>
2024-05-09 02:14 ` Re: Slow catchup of 2PC (twophase) transactions on replica in LR Peter Smith <[email protected]>
2024-05-09 08:26 ` RE: Slow catchup of 2PC (twophase) transactions on replica in LR Hayato Kuroda (Fujitsu) <[email protected]>
2024-05-09 02:21 ` Re: Slow catchup of 2PC (twophase) transactions on replica in LR Peter Smith <[email protected]>
2024-05-09 08:54 ` RE: Slow catchup of 2PC (twophase) transactions on replica in LR Hayato Kuroda (Fujitsu) <[email protected]>
2024-05-09 06:11 ` Re: Slow catchup of 2PC (twophase) transactions on replica in LR Peter Smith <[email protected]>
2024-05-09 09:10 ` RE: Slow catchup of 2PC (twophase) transactions on replica in LR Hayato Kuroda (Fujitsu) <[email protected]>
2024-05-09 07:28 ` Re: Slow catchup of 2PC (twophase) transactions on replica in LR Peter Smith <[email protected]>
2024-05-09 09:15 ` RE: Slow catchup of 2PC (twophase) transactions on replica in LR Hayato Kuroda (Fujitsu) <[email protected]>
2024-05-13 06:34 ` Re: Slow catchup of 2PC (twophase) transactions on replica in LR Peter Smith <[email protected]>
2024-05-13 12:25 ` RE: Slow catchup of 2PC (twophase) transactions on replica in LR Hayato Kuroda (Fujitsu) <[email protected]>
2024-05-14 04:06 ` Re: Slow catchup of 2PC (twophase) transactions on replica in LR Peter Smith <[email protected]>
2024-05-14 04:18 ` Re: Slow catchup of 2PC (twophase) transactions on replica in LR Peter Smith <[email protected]>
2024-05-14 12:03 ` RE: Slow catchup of 2PC (twophase) transactions on replica in LR Hayato Kuroda (Fujitsu) <[email protected]>
2024-05-15 05:02 ` Re: Slow catchup of 2PC (twophase) transactions on replica in LR Peter Smith <[email protected]>
2024-05-16 05:02 ` RE: Slow catchup of 2PC (twophase) transactions on replica in LR Hayato Kuroda (Fujitsu) <[email protected]>
2024-05-17 02:20 ` Re: Slow catchup of 2PC (twophase) transactions on replica in LR Peter Smith <[email protected]>
2024-05-15 05:12 ` Re: Slow catchup of 2PC (twophase) transactions on replica in LR Peter Smith <[email protected]>
2024-05-16 05:04 ` RE: Slow catchup of 2PC (twophase) transactions on replica in LR Hayato Kuroda (Fujitsu) <[email protected]>
2024-05-13 06:37 ` Re: Slow catchup of 2PC (twophase) transactions on replica in LR Peter Smith <[email protected]>
2024-05-13 12:27 ` RE: Slow catchup of 2PC (twophase) transactions on replica in LR Hayato Kuroda (Fujitsu) <[email protected]>
2024-05-13 06:40 ` Re: Slow catchup of 2PC (twophase) transactions on replica in LR Peter Smith <[email protected]>
2024-05-13 12:28 ` RE: Slow catchup of 2PC (twophase) transactions on replica in LR Hayato Kuroda (Fujitsu) <[email protected]>
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