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help / color / mirror / Atom feedFrom: Jelte Fennema <[email protected]>
To: Michael Banck <[email protected]>
Cc: Maxim Orlov <[email protected]>
Cc: Aleksander Alekseev <[email protected]>
Cc: [email protected] <[email protected]>
Subject: Re: [EXTERNAL] Re: Support load balancing in libpq
Date: Mon, 9 Jan 2023 13:00:01 +0000
Message-ID: <DBBPR83MB05079A565E6AB609104D3F9DF7FE9@DBBPR83MB0507.EURPRD83.prod.outlook.com> (raw)
In-Reply-To: <[email protected]>
References: <PR3PR83MB04768E2FF04818EEB2179949F7A69@PR3PR83MB0476.EURPRD83.prod.outlook.com>
<CAJ7c6TNkG1EMqtvCOt2t06J+Bep6VsZ+NtmuPr89TXWxr614JQ@mail.gmail.com>
<PR3PR83MB0476EC95BA95CE33F952F80AF7B39@PR3PR83MB0476.EURPRD83.prod.outlook.com>
<[email protected]>
<DBBPR83MB05074E85346C3041109E2353F7449@DBBPR83MB0507.EURPRD83.prod.outlook.com>
<CACG=ezYazYUj3TQVSPL-G5Bhea0hApTbknhAbCX=yNDdu=gpyw@mail.gmail.com>
<[email protected]>
<DBBPR83MB0507F1883B6B0E4BA2E60195F75B9@DBBPR83MB0507.EURPRD83.prod.outlook.com>
<DBBPR83MB05074EEEA8AB347BB70A687CF7129@DBBPR83MB0507.EURPRD83.prod.outlook.com>
<[email protected]>
Attached an updated patch which should address your feedback and
I updated the commit message.
> I wonder whether making the parameter a boolean will paint us into a
> corner
I made it a string option, just like target_session_attrs. I'm pretty sure a
round-robin load balancing policy could be implemented in the future
given certain constraints, like connections being made within the same
process. I adjusted the docs accordingly.
> > +typedef struct
> > +{
> > + int family;
> > + SockAddr addr;
> > +} AddrInfo;
>
> That last line looks weirdly indented compared to SockAddr; in the
> struct above.
Yes I agree, but for some reason pgindent really badly wants it formatted
that way. I now undid the changes made by pgindent manually.
> I wonder whether this needs to be documented if it is mostly a
> development/testing parameter?
I also wasn't sure whether it should be documented or not. I'm fine with
either, I'll leave it in for now and let a committer decide if it's wanted or not.
> A bit unclear why you put the variables at this point in the list, but
> the list doesn't seem to be ordered strictly anyway; still, maybe they
> would fit best at the bottom below target_session_attrs?
Good point, I added them after target_session_attrs now and also moved
docs/parsing accordingly. This makes conceptually to me as well, since
target_session_attrs and load_balance_hosts have some interesting
sense contextually too.
P.S. I also attached the same pgindent run patch that I added in
https://www.postgresql.org/message-id/flat/[email protected]...
Attachments:
[application/octet-stream] v6-0001-libpq-Run-pgindent-after-a9e9a9f32b3.patch (39.3K, ../DBBPR83MB05079A565E6AB609104D3F9DF7FE9@DBBPR83MB0507.EURPRD83.prod.outlook.com/2-v6-0001-libpq-Run-pgindent-after-a9e9a9f32b3.patch)
download | inline diff:
From beb005477c16af285df7fc068bfc2def70e5acf8 Mon Sep 17 00:00:00 2001
From: Jelte Fennema <[email protected]>
Date: Wed, 30 Nov 2022 10:07:19 +0100
Subject: [PATCH v6 1/2] libpq: Run pgindent after a9e9a9f32b3
It seems that pgindent was not run after the error handling refactor in
commit a9e9a9f32b35edf129c88e8b929ef223f8511f59. This fixes that and
also addresses a few other things pgindent wanted to change in libpq.
---
src/interfaces/libpq/fe-auth-scram.c | 2 +-
src/interfaces/libpq/fe-auth.c | 8 +-
src/interfaces/libpq/fe-connect.c | 124 +++++++++++------------
src/interfaces/libpq/fe-exec.c | 16 +--
src/interfaces/libpq/fe-lobj.c | 42 ++++----
src/interfaces/libpq/fe-misc.c | 10 +-
src/interfaces/libpq/fe-protocol3.c | 2 +-
src/interfaces/libpq/fe-secure-common.c | 6 +-
src/interfaces/libpq/fe-secure-gssapi.c | 12 +--
src/interfaces/libpq/fe-secure-openssl.c | 64 ++++++------
src/interfaces/libpq/fe-secure.c | 8 +-
src/interfaces/libpq/libpq-int.h | 4 +-
12 files changed, 149 insertions(+), 149 deletions(-)
diff --git a/src/interfaces/libpq/fe-auth-scram.c b/src/interfaces/libpq/fe-auth-scram.c
index 9c42ea4f81..12c3d0bc33 100644
--- a/src/interfaces/libpq/fe-auth-scram.c
+++ b/src/interfaces/libpq/fe-auth-scram.c
@@ -716,7 +716,7 @@ read_server_final_message(fe_scram_state *state, char *input)
return false;
}
libpq_append_conn_error(conn, "error received from server in SCRAM exchange: %s",
- errmsg);
+ errmsg);
return false;
}
diff --git a/src/interfaces/libpq/fe-auth.c b/src/interfaces/libpq/fe-auth.c
index 9afc6f19b9..ab454e6cd0 100644
--- a/src/interfaces/libpq/fe-auth.c
+++ b/src/interfaces/libpq/fe-auth.c
@@ -73,7 +73,7 @@ pg_GSS_continue(PGconn *conn, int payloadlen)
if (!ginbuf.value)
{
libpq_append_conn_error(conn, "out of memory allocating GSSAPI buffer (%d)",
- payloadlen);
+ payloadlen);
return STATUS_ERROR;
}
if (pqGetnchar(ginbuf.value, payloadlen, conn))
@@ -223,7 +223,7 @@ pg_SSPI_continue(PGconn *conn, int payloadlen)
if (!inputbuf)
{
libpq_append_conn_error(conn, "out of memory allocating SSPI buffer (%d)",
- payloadlen);
+ payloadlen);
return STATUS_ERROR;
}
if (pqGetnchar(inputbuf, payloadlen, conn))
@@ -623,7 +623,7 @@ pg_SASL_continue(PGconn *conn, int payloadlen, bool final)
if (!challenge)
{
libpq_append_conn_error(conn, "out of memory allocating SASL buffer (%d)",
- payloadlen);
+ payloadlen);
return STATUS_ERROR;
}
@@ -1277,7 +1277,7 @@ PQencryptPasswordConn(PGconn *conn, const char *passwd, const char *user,
else
{
libpq_append_conn_error(conn, "unrecognized password encryption algorithm \"%s\"",
- algorithm);
+ algorithm);
return NULL;
}
diff --git a/src/interfaces/libpq/fe-connect.c b/src/interfaces/libpq/fe-connect.c
index 50b5df3490..773e9e1f3a 100644
--- a/src/interfaces/libpq/fe-connect.c
+++ b/src/interfaces/libpq/fe-connect.c
@@ -1079,7 +1079,7 @@ connectOptions2(PGconn *conn)
{
conn->status = CONNECTION_BAD;
libpq_append_conn_error(conn, "could not match %d host names to %d hostaddr values",
- count_comma_separated_elems(conn->pghost), conn->nconnhost);
+ count_comma_separated_elems(conn->pghost), conn->nconnhost);
return false;
}
}
@@ -1159,7 +1159,7 @@ connectOptions2(PGconn *conn)
{
conn->status = CONNECTION_BAD;
libpq_append_conn_error(conn, "could not match %d port numbers to %d hosts",
- count_comma_separated_elems(conn->pgport), conn->nconnhost);
+ count_comma_separated_elems(conn->pgport), conn->nconnhost);
return false;
}
}
@@ -1248,7 +1248,7 @@ connectOptions2(PGconn *conn)
{
conn->status = CONNECTION_BAD;
libpq_append_conn_error(conn, "invalid %s value: \"%s\"",
- "channel_binding", conn->channel_binding);
+ "channel_binding", conn->channel_binding);
return false;
}
}
@@ -1273,7 +1273,7 @@ connectOptions2(PGconn *conn)
{
conn->status = CONNECTION_BAD;
libpq_append_conn_error(conn, "invalid %s value: \"%s\"",
- "sslmode", conn->sslmode);
+ "sslmode", conn->sslmode);
return false;
}
@@ -1293,7 +1293,7 @@ connectOptions2(PGconn *conn)
case 'v': /* "verify-ca" or "verify-full" */
conn->status = CONNECTION_BAD;
libpq_append_conn_error(conn, "sslmode value \"%s\" invalid when SSL support is not compiled in",
- conn->sslmode);
+ conn->sslmode);
return false;
}
#endif
@@ -1313,16 +1313,16 @@ connectOptions2(PGconn *conn)
{
conn->status = CONNECTION_BAD;
libpq_append_conn_error(conn, "invalid %s value: \"%s\"",
- "ssl_min_protocol_version",
- conn->ssl_min_protocol_version);
+ "ssl_min_protocol_version",
+ conn->ssl_min_protocol_version);
return false;
}
if (!sslVerifyProtocolVersion(conn->ssl_max_protocol_version))
{
conn->status = CONNECTION_BAD;
libpq_append_conn_error(conn, "invalid %s value: \"%s\"",
- "ssl_max_protocol_version",
- conn->ssl_max_protocol_version);
+ "ssl_max_protocol_version",
+ conn->ssl_max_protocol_version);
return false;
}
@@ -1359,7 +1359,7 @@ connectOptions2(PGconn *conn)
{
conn->status = CONNECTION_BAD;
libpq_append_conn_error(conn, "gssencmode value \"%s\" invalid when GSSAPI support is not compiled in",
- conn->gssencmode);
+ conn->gssencmode);
return false;
}
#endif
@@ -1392,8 +1392,8 @@ connectOptions2(PGconn *conn)
{
conn->status = CONNECTION_BAD;
libpq_append_conn_error(conn, "invalid %s value: \"%s\"",
- "target_session_attrs",
- conn->target_session_attrs);
+ "target_session_attrs",
+ conn->target_session_attrs);
return false;
}
}
@@ -1609,7 +1609,7 @@ connectNoDelay(PGconn *conn)
char sebuf[PG_STRERROR_R_BUFLEN];
libpq_append_conn_error(conn, "could not set socket to TCP no delay mode: %s",
- SOCK_STRERROR(SOCK_ERRNO, sebuf, sizeof(sebuf)));
+ SOCK_STRERROR(SOCK_ERRNO, sebuf, sizeof(sebuf)));
return 0;
}
#endif
@@ -1787,7 +1787,7 @@ parse_int_param(const char *value, int *result, PGconn *conn,
error:
libpq_append_conn_error(conn, "invalid integer value \"%s\" for connection option \"%s\"",
- value, context);
+ value, context);
return false;
}
@@ -1816,9 +1816,9 @@ setKeepalivesIdle(PGconn *conn)
char sebuf[PG_STRERROR_R_BUFLEN];
libpq_append_conn_error(conn, "%s(%s) failed: %s",
- "setsockopt",
- PG_TCP_KEEPALIVE_IDLE_STR,
- SOCK_STRERROR(SOCK_ERRNO, sebuf, sizeof(sebuf)));
+ "setsockopt",
+ PG_TCP_KEEPALIVE_IDLE_STR,
+ SOCK_STRERROR(SOCK_ERRNO, sebuf, sizeof(sebuf)));
return 0;
}
#endif
@@ -1850,9 +1850,9 @@ setKeepalivesInterval(PGconn *conn)
char sebuf[PG_STRERROR_R_BUFLEN];
libpq_append_conn_error(conn, "%s(%s) failed: %s",
- "setsockopt",
- "TCP_KEEPINTVL",
- SOCK_STRERROR(SOCK_ERRNO, sebuf, sizeof(sebuf)));
+ "setsockopt",
+ "TCP_KEEPINTVL",
+ SOCK_STRERROR(SOCK_ERRNO, sebuf, sizeof(sebuf)));
return 0;
}
#endif
@@ -1885,9 +1885,9 @@ setKeepalivesCount(PGconn *conn)
char sebuf[PG_STRERROR_R_BUFLEN];
libpq_append_conn_error(conn, "%s(%s) failed: %s",
- "setsockopt",
- "TCP_KEEPCNT",
- SOCK_STRERROR(SOCK_ERRNO, sebuf, sizeof(sebuf)));
+ "setsockopt",
+ "TCP_KEEPCNT",
+ SOCK_STRERROR(SOCK_ERRNO, sebuf, sizeof(sebuf)));
return 0;
}
#endif
@@ -1949,8 +1949,8 @@ prepKeepalivesWin32(PGconn *conn)
if (!setKeepalivesWin32(conn->sock, idle, interval))
{
libpq_append_conn_error(conn, "%s(%s) failed: error code %d",
- "WSAIoctl", "SIO_KEEPALIVE_VALS",
- WSAGetLastError());
+ "WSAIoctl", "SIO_KEEPALIVE_VALS",
+ WSAGetLastError());
return 0;
}
return 1;
@@ -1983,9 +1983,9 @@ setTCPUserTimeout(PGconn *conn)
char sebuf[256];
libpq_append_conn_error(conn, "%s(%s) failed: %s",
- "setsockopt",
- "TCP_USER_TIMEOUT",
- SOCK_STRERROR(SOCK_ERRNO, sebuf, sizeof(sebuf)));
+ "setsockopt",
+ "TCP_USER_TIMEOUT",
+ SOCK_STRERROR(SOCK_ERRNO, sebuf, sizeof(sebuf)));
return 0;
}
#endif
@@ -2354,7 +2354,7 @@ keep_going: /* We will come back to here until there is
if (ret || !conn->addrlist)
{
libpq_append_conn_error(conn, "could not translate host name \"%s\" to address: %s",
- ch->host, gai_strerror(ret));
+ ch->host, gai_strerror(ret));
goto keep_going;
}
break;
@@ -2366,7 +2366,7 @@ keep_going: /* We will come back to here until there is
if (ret || !conn->addrlist)
{
libpq_append_conn_error(conn, "could not parse network address \"%s\": %s",
- ch->hostaddr, gai_strerror(ret));
+ ch->hostaddr, gai_strerror(ret));
goto keep_going;
}
break;
@@ -2377,8 +2377,8 @@ keep_going: /* We will come back to here until there is
if (strlen(portstr) >= UNIXSOCK_PATH_BUFLEN)
{
libpq_append_conn_error(conn, "Unix-domain socket path \"%s\" is too long (maximum %d bytes)",
- portstr,
- (int) (UNIXSOCK_PATH_BUFLEN - 1));
+ portstr,
+ (int) (UNIXSOCK_PATH_BUFLEN - 1));
goto keep_going;
}
@@ -2391,7 +2391,7 @@ keep_going: /* We will come back to here until there is
if (ret || !conn->addrlist)
{
libpq_append_conn_error(conn, "could not translate Unix-domain socket path \"%s\" to address: %s",
- portstr, gai_strerror(ret));
+ portstr, gai_strerror(ret));
goto keep_going;
}
break;
@@ -2513,7 +2513,7 @@ keep_going: /* We will come back to here until there is
}
emitHostIdentityInfo(conn, host_addr);
libpq_append_conn_error(conn, "could not create socket: %s",
- SOCK_STRERROR(errorno, sebuf, sizeof(sebuf)));
+ SOCK_STRERROR(errorno, sebuf, sizeof(sebuf)));
goto error_return;
}
@@ -2543,7 +2543,7 @@ keep_going: /* We will come back to here until there is
if (!pg_set_noblock(conn->sock))
{
libpq_append_conn_error(conn, "could not set socket to nonblocking mode: %s",
- SOCK_STRERROR(SOCK_ERRNO, sebuf, sizeof(sebuf)));
+ SOCK_STRERROR(SOCK_ERRNO, sebuf, sizeof(sebuf)));
conn->try_next_addr = true;
goto keep_going;
}
@@ -2552,7 +2552,7 @@ keep_going: /* We will come back to here until there is
if (fcntl(conn->sock, F_SETFD, FD_CLOEXEC) == -1)
{
libpq_append_conn_error(conn, "could not set socket to close-on-exec mode: %s",
- SOCK_STRERROR(SOCK_ERRNO, sebuf, sizeof(sebuf)));
+ SOCK_STRERROR(SOCK_ERRNO, sebuf, sizeof(sebuf)));
conn->try_next_addr = true;
goto keep_going;
}
@@ -2581,9 +2581,9 @@ keep_going: /* We will come back to here until there is
(char *) &on, sizeof(on)) < 0)
{
libpq_append_conn_error(conn, "%s(%s) failed: %s",
- "setsockopt",
- "SO_KEEPALIVE",
- SOCK_STRERROR(SOCK_ERRNO, sebuf, sizeof(sebuf)));
+ "setsockopt",
+ "SO_KEEPALIVE",
+ SOCK_STRERROR(SOCK_ERRNO, sebuf, sizeof(sebuf)));
err = 1;
}
else if (!setKeepalivesIdle(conn)
@@ -2708,7 +2708,7 @@ keep_going: /* We will come back to here until there is
(char *) &optval, &optlen) == -1)
{
libpq_append_conn_error(conn, "could not get socket error status: %s",
- SOCK_STRERROR(SOCK_ERRNO, sebuf, sizeof(sebuf)));
+ SOCK_STRERROR(SOCK_ERRNO, sebuf, sizeof(sebuf)));
goto error_return;
}
else if (optval != 0)
@@ -2735,7 +2735,7 @@ keep_going: /* We will come back to here until there is
&conn->laddr.salen) < 0)
{
libpq_append_conn_error(conn, "could not get client address from socket: %s",
- SOCK_STRERROR(SOCK_ERRNO, sebuf, sizeof(sebuf)));
+ SOCK_STRERROR(SOCK_ERRNO, sebuf, sizeof(sebuf)));
goto error_return;
}
@@ -2775,7 +2775,7 @@ keep_going: /* We will come back to here until there is
libpq_append_conn_error(conn, "requirepeer parameter is not supported on this platform");
else
libpq_append_conn_error(conn, "could not get peer credentials: %s",
- strerror_r(errno, sebuf, sizeof(sebuf)));
+ strerror_r(errno, sebuf, sizeof(sebuf)));
goto error_return;
}
@@ -2788,7 +2788,7 @@ keep_going: /* We will come back to here until there is
if (strcmp(remote_username, conn->requirepeer) != 0)
{
libpq_append_conn_error(conn, "requirepeer specifies \"%s\", but actual peer user name is \"%s\"",
- conn->requirepeer, remote_username);
+ conn->requirepeer, remote_username);
free(remote_username);
goto error_return;
}
@@ -2829,7 +2829,7 @@ keep_going: /* We will come back to here until there is
if (pqPacketSend(conn, 0, &pv, sizeof(pv)) != STATUS_OK)
{
libpq_append_conn_error(conn, "could not send GSSAPI negotiation packet: %s",
- SOCK_STRERROR(SOCK_ERRNO, sebuf, sizeof(sebuf)));
+ SOCK_STRERROR(SOCK_ERRNO, sebuf, sizeof(sebuf)));
goto error_return;
}
@@ -2840,7 +2840,7 @@ keep_going: /* We will come back to here until there is
else if (!conn->gctx && conn->gssencmode[0] == 'r')
{
libpq_append_conn_error(conn,
- "GSSAPI encryption required but was impossible (possibly no credential cache, no server support, or using a local socket)");
+ "GSSAPI encryption required but was impossible (possibly no credential cache, no server support, or using a local socket)");
goto error_return;
}
#endif
@@ -2882,7 +2882,7 @@ keep_going: /* We will come back to here until there is
if (pqPacketSend(conn, 0, &pv, sizeof(pv)) != STATUS_OK)
{
libpq_append_conn_error(conn, "could not send SSL negotiation packet: %s",
- SOCK_STRERROR(SOCK_ERRNO, sebuf, sizeof(sebuf)));
+ SOCK_STRERROR(SOCK_ERRNO, sebuf, sizeof(sebuf)));
goto error_return;
}
/* Ok, wait for response */
@@ -2911,7 +2911,7 @@ keep_going: /* We will come back to here until there is
if (pqPacketSend(conn, 0, startpacket, packetlen) != STATUS_OK)
{
libpq_append_conn_error(conn, "could not send startup packet: %s",
- SOCK_STRERROR(SOCK_ERRNO, sebuf, sizeof(sebuf)));
+ SOCK_STRERROR(SOCK_ERRNO, sebuf, sizeof(sebuf)));
free(startpacket);
goto error_return;
}
@@ -3012,7 +3012,7 @@ keep_going: /* We will come back to here until there is
else
{
libpq_append_conn_error(conn, "received invalid response to SSL negotiation: %c",
- SSLok);
+ SSLok);
goto error_return;
}
}
@@ -3123,7 +3123,7 @@ keep_going: /* We will come back to here until there is
else if (gss_ok != 'G')
{
libpq_append_conn_error(conn, "received invalid response to GSSAPI negotiation: %c",
- gss_ok);
+ gss_ok);
goto error_return;
}
}
@@ -3201,7 +3201,7 @@ keep_going: /* We will come back to here until there is
if (!(beresp == 'R' || beresp == 'v' || beresp == 'E'))
{
libpq_append_conn_error(conn, "expected authentication request from server, but received %c",
- beresp);
+ beresp);
goto error_return;
}
@@ -3216,17 +3216,17 @@ keep_going: /* We will come back to here until there is
* Try to validate message length before using it.
* Authentication requests can't be very large, although GSS
* auth requests may not be that small. Same for
- * NegotiateProtocolVersion. Errors can be a
- * little larger, but not huge. If we see a large apparent
- * length in an error, it means we're really talking to a
- * pre-3.0-protocol server; cope. (Before version 14, the
- * server also used the old protocol for errors that happened
- * before processing the startup packet.)
+ * NegotiateProtocolVersion. Errors can be a little larger,
+ * but not huge. If we see a large apparent length in an
+ * error, it means we're really talking to a pre-3.0-protocol
+ * server; cope. (Before version 14, the server also used the
+ * old protocol for errors that happened before processing the
+ * startup packet.)
*/
if ((beresp == 'R' || beresp == 'v') && (msgLength < 8 || msgLength > 2000))
{
libpq_append_conn_error(conn, "expected authentication request from server, but received %c",
- beresp);
+ beresp);
goto error_return;
}
@@ -3705,7 +3705,7 @@ keep_going: /* We will come back to here until there is
/* Append error report to conn->errorMessage. */
libpq_append_conn_error(conn, "\"%s\" failed",
- "SHOW transaction_read_only");
+ "SHOW transaction_read_only");
/* Close connection politely. */
conn->status = CONNECTION_OK;
@@ -3755,7 +3755,7 @@ keep_going: /* We will come back to here until there is
/* Append error report to conn->errorMessage. */
libpq_append_conn_error(conn, "\"%s\" failed",
- "SELECT pg_is_in_recovery()");
+ "SELECT pg_is_in_recovery()");
/* Close connection politely. */
conn->status = CONNECTION_OK;
@@ -3768,8 +3768,8 @@ keep_going: /* We will come back to here until there is
default:
libpq_append_conn_error(conn,
- "invalid connection state %d, probably indicative of memory corruption",
- conn->status);
+ "invalid connection state %d, probably indicative of memory corruption",
+ conn->status);
goto error_return;
}
@@ -7148,7 +7148,7 @@ pgpassfileWarning(PGconn *conn)
if (sqlstate && strcmp(sqlstate, ERRCODE_INVALID_PASSWORD) == 0)
libpq_append_conn_error(conn, "password retrieved from file \"%s\"",
- conn->pgpassfile);
+ conn->pgpassfile);
}
}
diff --git a/src/interfaces/libpq/fe-exec.c b/src/interfaces/libpq/fe-exec.c
index ec62550e38..0c2dae6ed9 100644
--- a/src/interfaces/libpq/fe-exec.c
+++ b/src/interfaces/libpq/fe-exec.c
@@ -1444,7 +1444,7 @@ PQsendQueryInternal(PGconn *conn, const char *query, bool newQuery)
if (conn->pipelineStatus != PQ_PIPELINE_OFF)
{
libpq_append_conn_error(conn, "%s not allowed in pipeline mode",
- "PQsendQuery");
+ "PQsendQuery");
return 0;
}
@@ -1512,7 +1512,7 @@ PQsendQueryParams(PGconn *conn,
if (nParams < 0 || nParams > PQ_QUERY_PARAM_MAX_LIMIT)
{
libpq_append_conn_error(conn, "number of parameters must be between 0 and %d",
- PQ_QUERY_PARAM_MAX_LIMIT);
+ PQ_QUERY_PARAM_MAX_LIMIT);
return 0;
}
@@ -1558,7 +1558,7 @@ PQsendPrepare(PGconn *conn,
if (nParams < 0 || nParams > PQ_QUERY_PARAM_MAX_LIMIT)
{
libpq_append_conn_error(conn, "number of parameters must be between 0 and %d",
- PQ_QUERY_PARAM_MAX_LIMIT);
+ PQ_QUERY_PARAM_MAX_LIMIT);
return 0;
}
@@ -1652,7 +1652,7 @@ PQsendQueryPrepared(PGconn *conn,
if (nParams < 0 || nParams > PQ_QUERY_PARAM_MAX_LIMIT)
{
libpq_append_conn_error(conn, "number of parameters must be between 0 and %d",
- PQ_QUERY_PARAM_MAX_LIMIT);
+ PQ_QUERY_PARAM_MAX_LIMIT);
return 0;
}
@@ -2099,10 +2099,9 @@ PQgetResult(PGconn *conn)
/*
* We're about to return the NULL that terminates the round of
- * results from the current query; prepare to send the results
- * of the next query, if any, when we're called next. If there's
- * no next element in the command queue, this gets us in IDLE
- * state.
+ * results from the current query; prepare to send the results of
+ * the next query, if any, when we're called next. If there's no
+ * next element in the command queue, this gets us in IDLE state.
*/
pqPipelineProcessQueue(conn);
res = NULL; /* query is complete */
@@ -3047,6 +3046,7 @@ pqPipelineProcessQueue(PGconn *conn)
return;
case PGASYNC_IDLE:
+
/*
* If we're in IDLE mode and there's some command in the queue,
* get us into PIPELINE_IDLE mode and process normally. Otherwise
diff --git a/src/interfaces/libpq/fe-lobj.c b/src/interfaces/libpq/fe-lobj.c
index 4cb6a46859..206266fd04 100644
--- a/src/interfaces/libpq/fe-lobj.c
+++ b/src/interfaces/libpq/fe-lobj.c
@@ -142,7 +142,7 @@ lo_truncate(PGconn *conn, int fd, size_t len)
if (conn->lobjfuncs->fn_lo_truncate == 0)
{
libpq_append_conn_error(conn, "cannot determine OID of function %s",
- "lo_truncate");
+ "lo_truncate");
return -1;
}
@@ -205,7 +205,7 @@ lo_truncate64(PGconn *conn, int fd, pg_int64 len)
if (conn->lobjfuncs->fn_lo_truncate64 == 0)
{
libpq_append_conn_error(conn, "cannot determine OID of function %s",
- "lo_truncate64");
+ "lo_truncate64");
return -1;
}
@@ -395,7 +395,7 @@ lo_lseek64(PGconn *conn, int fd, pg_int64 offset, int whence)
if (conn->lobjfuncs->fn_lo_lseek64 == 0)
{
libpq_append_conn_error(conn, "cannot determine OID of function %s",
- "lo_lseek64");
+ "lo_lseek64");
return -1;
}
@@ -485,7 +485,7 @@ lo_create(PGconn *conn, Oid lobjId)
if (conn->lobjfuncs->fn_lo_create == 0)
{
libpq_append_conn_error(conn, "cannot determine OID of function %s",
- "lo_create");
+ "lo_create");
return InvalidOid;
}
@@ -558,7 +558,7 @@ lo_tell64(PGconn *conn, int fd)
if (conn->lobjfuncs->fn_lo_tell64 == 0)
{
libpq_append_conn_error(conn, "cannot determine OID of function %s",
- "lo_tell64");
+ "lo_tell64");
return -1;
}
@@ -667,7 +667,7 @@ lo_import_internal(PGconn *conn, const char *filename, Oid oid)
if (fd < 0)
{ /* error */
libpq_append_conn_error(conn, "could not open file \"%s\": %s",
- filename, strerror_r(errno, sebuf, sizeof(sebuf)));
+ filename, strerror_r(errno, sebuf, sizeof(sebuf)));
return InvalidOid;
}
@@ -723,8 +723,8 @@ lo_import_internal(PGconn *conn, const char *filename, Oid oid)
/* deliberately overwrite any error from lo_close */
pqClearConnErrorState(conn);
libpq_append_conn_error(conn, "could not read from file \"%s\": %s",
- filename,
- strerror_r(save_errno, sebuf, sizeof(sebuf)));
+ filename,
+ strerror_r(save_errno, sebuf, sizeof(sebuf)));
return InvalidOid;
}
@@ -778,8 +778,8 @@ lo_export(PGconn *conn, Oid lobjId, const char *filename)
/* deliberately overwrite any error from lo_close */
pqClearConnErrorState(conn);
libpq_append_conn_error(conn, "could not open file \"%s\": %s",
- filename,
- strerror_r(save_errno, sebuf, sizeof(sebuf)));
+ filename,
+ strerror_r(save_errno, sebuf, sizeof(sebuf)));
return -1;
}
@@ -799,8 +799,8 @@ lo_export(PGconn *conn, Oid lobjId, const char *filename)
/* deliberately overwrite any error from lo_close */
pqClearConnErrorState(conn);
libpq_append_conn_error(conn, "could not write to file \"%s\": %s",
- filename,
- strerror_r(save_errno, sebuf, sizeof(sebuf)));
+ filename,
+ strerror_r(save_errno, sebuf, sizeof(sebuf)));
return -1;
}
}
@@ -822,7 +822,7 @@ lo_export(PGconn *conn, Oid lobjId, const char *filename)
if (close(fd) != 0 && result >= 0)
{
libpq_append_conn_error(conn, "could not write to file \"%s\": %s",
- filename, strerror_r(errno, sebuf, sizeof(sebuf)));
+ filename, strerror_r(errno, sebuf, sizeof(sebuf)));
result = -1;
}
@@ -954,56 +954,56 @@ lo_initialize(PGconn *conn)
if (lobjfuncs->fn_lo_open == 0)
{
libpq_append_conn_error(conn, "cannot determine OID of function %s",
- "lo_open");
+ "lo_open");
free(lobjfuncs);
return -1;
}
if (lobjfuncs->fn_lo_close == 0)
{
libpq_append_conn_error(conn, "cannot determine OID of function %s",
- "lo_close");
+ "lo_close");
free(lobjfuncs);
return -1;
}
if (lobjfuncs->fn_lo_creat == 0)
{
libpq_append_conn_error(conn, "cannot determine OID of function %s",
- "lo_creat");
+ "lo_creat");
free(lobjfuncs);
return -1;
}
if (lobjfuncs->fn_lo_unlink == 0)
{
libpq_append_conn_error(conn, "cannot determine OID of function %s",
- "lo_unlink");
+ "lo_unlink");
free(lobjfuncs);
return -1;
}
if (lobjfuncs->fn_lo_lseek == 0)
{
libpq_append_conn_error(conn, "cannot determine OID of function %s",
- "lo_lseek");
+ "lo_lseek");
free(lobjfuncs);
return -1;
}
if (lobjfuncs->fn_lo_tell == 0)
{
libpq_append_conn_error(conn, "cannot determine OID of function %s",
- "lo_tell");
+ "lo_tell");
free(lobjfuncs);
return -1;
}
if (lobjfuncs->fn_lo_read == 0)
{
libpq_append_conn_error(conn, "cannot determine OID of function %s",
- "loread");
+ "loread");
free(lobjfuncs);
return -1;
}
if (lobjfuncs->fn_lo_write == 0)
{
libpq_append_conn_error(conn, "cannot determine OID of function %s",
- "lowrite");
+ "lowrite");
free(lobjfuncs);
return -1;
}
diff --git a/src/interfaces/libpq/fe-misc.c b/src/interfaces/libpq/fe-misc.c
index 3653a1a8a6..660cdec93c 100644
--- a/src/interfaces/libpq/fe-misc.c
+++ b/src/interfaces/libpq/fe-misc.c
@@ -749,8 +749,8 @@ retry4:
*/
definitelyEOF:
libpq_append_conn_error(conn, "server closed the connection unexpectedly\n"
- "\tThis probably means the server terminated abnormally\n"
- "\tbefore or while processing the request.");
+ "\tThis probably means the server terminated abnormally\n"
+ "\tbefore or while processing the request.");
/* Come here if lower-level code already set a suitable errorMessage */
definitelyFailed:
@@ -1067,7 +1067,7 @@ pqSocketCheck(PGconn *conn, int forRead, int forWrite, time_t end_time)
char sebuf[PG_STRERROR_R_BUFLEN];
libpq_append_conn_error(conn, "%s() failed: %s", "select",
- SOCK_STRERROR(SOCK_ERRNO, sebuf, sizeof(sebuf)));
+ SOCK_STRERROR(SOCK_ERRNO, sebuf, sizeof(sebuf)));
}
return result;
@@ -1280,7 +1280,7 @@ libpq_ngettext(const char *msgid, const char *msgid_plural, unsigned long n)
* newline.
*/
void
-libpq_append_error(PQExpBuffer errorMessage, const char *fmt, ...)
+libpq_append_error(PQExpBuffer errorMessage, const char *fmt,...)
{
int save_errno = errno;
bool done;
@@ -1309,7 +1309,7 @@ libpq_append_error(PQExpBuffer errorMessage, const char *fmt, ...)
* format should not end with a newline.
*/
void
-libpq_append_conn_error(PGconn *conn, const char *fmt, ...)
+libpq_append_conn_error(PGconn *conn, const char *fmt,...)
{
int save_errno = errno;
bool done;
diff --git a/src/interfaces/libpq/fe-protocol3.c b/src/interfaces/libpq/fe-protocol3.c
index 8ab6a88416..b79d74f748 100644
--- a/src/interfaces/libpq/fe-protocol3.c
+++ b/src/interfaces/libpq/fe-protocol3.c
@@ -466,7 +466,7 @@ static void
handleSyncLoss(PGconn *conn, char id, int msgLength)
{
libpq_append_conn_error(conn, "lost synchronization with server: got message type \"%c\", length %d",
- id, msgLength);
+ id, msgLength);
/* build an error result holding the error message */
pqSaveErrorResult(conn);
conn->asyncStatus = PGASYNC_READY; /* drop out of PQgetResult wait loop */
diff --git a/src/interfaces/libpq/fe-secure-common.c b/src/interfaces/libpq/fe-secure-common.c
index de115b3764..3ecc7bf615 100644
--- a/src/interfaces/libpq/fe-secure-common.c
+++ b/src/interfaces/libpq/fe-secure-common.c
@@ -226,7 +226,7 @@ pq_verify_peer_name_matches_certificate_ip(PGconn *conn,
* wrong given the subject matter.
*/
libpq_append_conn_error(conn, "certificate contains IP address with invalid length %zu",
- iplen);
+ iplen);
return -1;
}
@@ -235,7 +235,7 @@ pq_verify_peer_name_matches_certificate_ip(PGconn *conn,
if (!addrstr)
{
libpq_append_conn_error(conn, "could not convert certificate's IP address to string: %s",
- strerror_r(errno, sebuf, sizeof(sebuf)));
+ strerror_r(errno, sebuf, sizeof(sebuf)));
return -1;
}
@@ -292,7 +292,7 @@ pq_verify_peer_name_matches_certificate(PGconn *conn)
else if (names_examined == 1)
{
libpq_append_conn_error(conn, "server certificate for \"%s\" does not match host name \"%s\"",
- first_name, host);
+ first_name, host);
}
else
{
diff --git a/src/interfaces/libpq/fe-secure-gssapi.c b/src/interfaces/libpq/fe-secure-gssapi.c
index 6220e4a101..bed6e62435 100644
--- a/src/interfaces/libpq/fe-secure-gssapi.c
+++ b/src/interfaces/libpq/fe-secure-gssapi.c
@@ -213,8 +213,8 @@ pg_GSS_write(PGconn *conn, const void *ptr, size_t len)
if (output.length > PQ_GSS_SEND_BUFFER_SIZE - sizeof(uint32))
{
libpq_append_conn_error(conn, "client tried to send oversize GSSAPI packet (%zu > %zu)",
- (size_t) output.length,
- PQ_GSS_SEND_BUFFER_SIZE - sizeof(uint32));
+ (size_t) output.length,
+ PQ_GSS_SEND_BUFFER_SIZE - sizeof(uint32));
errno = EIO; /* for lack of a better idea */
goto cleanup;
}
@@ -349,8 +349,8 @@ pg_GSS_read(PGconn *conn, void *ptr, size_t len)
if (input.length > PQ_GSS_RECV_BUFFER_SIZE - sizeof(uint32))
{
libpq_append_conn_error(conn, "oversize GSSAPI packet sent by the server (%zu > %zu)",
- (size_t) input.length,
- PQ_GSS_RECV_BUFFER_SIZE - sizeof(uint32));
+ (size_t) input.length,
+ PQ_GSS_RECV_BUFFER_SIZE - sizeof(uint32));
errno = EIO; /* for lack of a better idea */
return -1;
}
@@ -588,8 +588,8 @@ pqsecure_open_gss(PGconn *conn)
if (input.length > PQ_GSS_RECV_BUFFER_SIZE - sizeof(uint32))
{
libpq_append_conn_error(conn, "oversize GSSAPI packet sent by the server (%zu > %zu)",
- (size_t) input.length,
- PQ_GSS_RECV_BUFFER_SIZE - sizeof(uint32));
+ (size_t) input.length,
+ PQ_GSS_RECV_BUFFER_SIZE - sizeof(uint32));
return PGRES_POLLING_FAILED;
}
diff --git a/src/interfaces/libpq/fe-secure-openssl.c b/src/interfaces/libpq/fe-secure-openssl.c
index 983536de25..ab2cbf045b 100644
--- a/src/interfaces/libpq/fe-secure-openssl.c
+++ b/src/interfaces/libpq/fe-secure-openssl.c
@@ -213,12 +213,12 @@ rloop:
if (result_errno == EPIPE ||
result_errno == ECONNRESET)
libpq_append_conn_error(conn, "server closed the connection unexpectedly\n"
- "\tThis probably means the server terminated abnormally\n"
- "\tbefore or while processing the request.");
+ "\tThis probably means the server terminated abnormally\n"
+ "\tbefore or while processing the request.");
else
libpq_append_conn_error(conn, "SSL SYSCALL error: %s",
- SOCK_STRERROR(result_errno,
- sebuf, sizeof(sebuf)));
+ SOCK_STRERROR(result_errno,
+ sebuf, sizeof(sebuf)));
}
else
{
@@ -313,12 +313,12 @@ pgtls_write(PGconn *conn, const void *ptr, size_t len)
result_errno = SOCK_ERRNO;
if (result_errno == EPIPE || result_errno == ECONNRESET)
libpq_append_conn_error(conn, "server closed the connection unexpectedly\n"
- "\tThis probably means the server terminated abnormally\n"
- "\tbefore or while processing the request.");
+ "\tThis probably means the server terminated abnormally\n"
+ "\tbefore or while processing the request.");
else
libpq_append_conn_error(conn, "SSL SYSCALL error: %s",
- SOCK_STRERROR(result_errno,
- sebuf, sizeof(sebuf)));
+ SOCK_STRERROR(result_errno,
+ sebuf, sizeof(sebuf)));
}
else
{
@@ -410,7 +410,7 @@ pgtls_get_peer_certificate_hash(PGconn *conn, size_t *len)
if (algo_type == NULL)
{
libpq_append_conn_error(conn, "could not find digest for NID %s",
- OBJ_nid2sn(algo_nid));
+ OBJ_nid2sn(algo_nid));
return NULL;
}
break;
@@ -962,7 +962,7 @@ initialize_SSL(PGconn *conn)
if (ssl_min_ver == -1)
{
libpq_append_conn_error(conn, "invalid value \"%s\" for minimum SSL protocol version",
- conn->ssl_min_protocol_version);
+ conn->ssl_min_protocol_version);
SSL_CTX_free(SSL_context);
return -1;
}
@@ -988,7 +988,7 @@ initialize_SSL(PGconn *conn)
if (ssl_max_ver == -1)
{
libpq_append_conn_error(conn, "invalid value \"%s\" for maximum SSL protocol version",
- conn->ssl_max_protocol_version);
+ conn->ssl_max_protocol_version);
SSL_CTX_free(SSL_context);
return -1;
}
@@ -1032,7 +1032,7 @@ initialize_SSL(PGconn *conn)
char *err = SSLerrmessage(ERR_get_error());
libpq_append_conn_error(conn, "could not read root certificate file \"%s\": %s",
- fnbuf, err);
+ fnbuf, err);
SSLerrfree(err);
SSL_CTX_free(SSL_context);
return -1;
@@ -1084,10 +1084,10 @@ initialize_SSL(PGconn *conn)
*/
if (fnbuf[0] == '\0')
libpq_append_conn_error(conn, "could not get home directory to locate root certificate file\n"
- "Either provide the file or change sslmode to disable server certificate verification.");
+ "Either provide the file or change sslmode to disable server certificate verification.");
else
libpq_append_conn_error(conn, "root certificate file \"%s\" does not exist\n"
- "Either provide the file or change sslmode to disable server certificate verification.", fnbuf);
+ "Either provide the file or change sslmode to disable server certificate verification.", fnbuf);
SSL_CTX_free(SSL_context);
return -1;
}
@@ -1117,7 +1117,7 @@ initialize_SSL(PGconn *conn)
if (errno != ENOENT && errno != ENOTDIR)
{
libpq_append_conn_error(conn, "could not open certificate file \"%s\": %s",
- fnbuf, strerror_r(errno, sebuf, sizeof(sebuf)));
+ fnbuf, strerror_r(errno, sebuf, sizeof(sebuf)));
SSL_CTX_free(SSL_context);
return -1;
}
@@ -1135,7 +1135,7 @@ initialize_SSL(PGconn *conn)
char *err = SSLerrmessage(ERR_get_error());
libpq_append_conn_error(conn, "could not read certificate file \"%s\": %s",
- fnbuf, err);
+ fnbuf, err);
SSLerrfree(err);
SSL_CTX_free(SSL_context);
return -1;
@@ -1234,7 +1234,7 @@ initialize_SSL(PGconn *conn)
char *err = SSLerrmessage(ERR_get_error());
libpq_append_conn_error(conn, "could not load SSL engine \"%s\": %s",
- engine_str, err);
+ engine_str, err);
SSLerrfree(err);
free(engine_str);
return -1;
@@ -1245,7 +1245,7 @@ initialize_SSL(PGconn *conn)
char *err = SSLerrmessage(ERR_get_error());
libpq_append_conn_error(conn, "could not initialize SSL engine \"%s\": %s",
- engine_str, err);
+ engine_str, err);
SSLerrfree(err);
ENGINE_free(conn->engine);
conn->engine = NULL;
@@ -1260,7 +1260,7 @@ initialize_SSL(PGconn *conn)
char *err = SSLerrmessage(ERR_get_error());
libpq_append_conn_error(conn, "could not read private SSL key \"%s\" from engine \"%s\": %s",
- engine_colon, engine_str, err);
+ engine_colon, engine_str, err);
SSLerrfree(err);
ENGINE_finish(conn->engine);
ENGINE_free(conn->engine);
@@ -1273,7 +1273,7 @@ initialize_SSL(PGconn *conn)
char *err = SSLerrmessage(ERR_get_error());
libpq_append_conn_error(conn, "could not load private SSL key \"%s\" from engine \"%s\": %s",
- engine_colon, engine_str, err);
+ engine_colon, engine_str, err);
SSLerrfree(err);
ENGINE_finish(conn->engine);
ENGINE_free(conn->engine);
@@ -1310,10 +1310,10 @@ initialize_SSL(PGconn *conn)
{
if (errno == ENOENT)
libpq_append_conn_error(conn, "certificate present, but not private key file \"%s\"",
- fnbuf);
+ fnbuf);
else
libpq_append_conn_error(conn, "could not stat private key file \"%s\": %m",
- fnbuf);
+ fnbuf);
return -1;
}
@@ -1321,7 +1321,7 @@ initialize_SSL(PGconn *conn)
if (!S_ISREG(buf.st_mode))
{
libpq_append_conn_error(conn, "private key file \"%s\" is not a regular file",
- fnbuf);
+ fnbuf);
return -1;
}
@@ -1378,7 +1378,7 @@ initialize_SSL(PGconn *conn)
if (SSL_use_PrivateKey_file(conn->ssl, fnbuf, SSL_FILETYPE_ASN1) != 1)
{
libpq_append_conn_error(conn, "could not load private key file \"%s\": %s",
- fnbuf, err);
+ fnbuf, err);
SSLerrfree(err);
return -1;
}
@@ -1394,7 +1394,7 @@ initialize_SSL(PGconn *conn)
char *err = SSLerrmessage(ERR_get_error());
libpq_append_conn_error(conn, "certificate does not match private key file \"%s\": %s",
- fnbuf, err);
+ fnbuf, err);
SSLerrfree(err);
return -1;
}
@@ -1447,7 +1447,7 @@ open_client_SSL(PGconn *conn)
if (r == -1)
libpq_append_conn_error(conn, "SSL SYSCALL error: %s",
- SOCK_STRERROR(SOCK_ERRNO, sebuf, sizeof(sebuf)));
+ SOCK_STRERROR(SOCK_ERRNO, sebuf, sizeof(sebuf)));
else
libpq_append_conn_error(conn, "SSL SYSCALL error: EOF detected");
pgtls_close(conn);
@@ -1489,12 +1489,12 @@ open_client_SSL(PGconn *conn)
case SSL_R_VERSION_TOO_LOW:
#endif
libpq_append_conn_error(conn, "This may indicate that the server does not support any SSL protocol version between %s and %s.",
- conn->ssl_min_protocol_version ?
- conn->ssl_min_protocol_version :
- MIN_OPENSSL_TLS_VERSION,
- conn->ssl_max_protocol_version ?
- conn->ssl_max_protocol_version :
- MAX_OPENSSL_TLS_VERSION);
+ conn->ssl_min_protocol_version ?
+ conn->ssl_min_protocol_version :
+ MIN_OPENSSL_TLS_VERSION,
+ conn->ssl_max_protocol_version ?
+ conn->ssl_max_protocol_version :
+ MAX_OPENSSL_TLS_VERSION);
break;
default:
break;
diff --git a/src/interfaces/libpq/fe-secure.c b/src/interfaces/libpq/fe-secure.c
index 66e401bf3d..8069e38142 100644
--- a/src/interfaces/libpq/fe-secure.c
+++ b/src/interfaces/libpq/fe-secure.c
@@ -255,14 +255,14 @@ pqsecure_raw_read(PGconn *conn, void *ptr, size_t len)
case EPIPE:
case ECONNRESET:
libpq_append_conn_error(conn, "server closed the connection unexpectedly\n"
- "\tThis probably means the server terminated abnormally\n"
- "\tbefore or while processing the request.");
+ "\tThis probably means the server terminated abnormally\n"
+ "\tbefore or while processing the request.");
break;
default:
libpq_append_conn_error(conn, "could not receive data from server: %s",
- SOCK_STRERROR(result_errno,
- sebuf, sizeof(sebuf)));
+ SOCK_STRERROR(result_errno,
+ sebuf, sizeof(sebuf)));
break;
}
}
diff --git a/src/interfaces/libpq/libpq-int.h b/src/interfaces/libpq/libpq-int.h
index d94b648ea5..712d572373 100644
--- a/src/interfaces/libpq/libpq-int.h
+++ b/src/interfaces/libpq/libpq-int.h
@@ -888,8 +888,8 @@ extern char *libpq_ngettext(const char *msgid, const char *msgid_plural, unsigne
*/
#undef _
-extern void libpq_append_error(PQExpBuffer errorMessage, const char *fmt, ...) pg_attribute_printf(2, 3);
-extern void libpq_append_conn_error(PGconn *conn, const char *fmt, ...) pg_attribute_printf(2, 3);
+extern void libpq_append_error(PQExpBuffer errorMessage, const char *fmt,...) pg_attribute_printf(2, 3);
+extern void libpq_append_conn_error(PGconn *conn, const char *fmt,...) pg_attribute_printf(2, 3);
/*
* These macros are needed to let error-handling code be portable between
--
2.34.1
[application/octet-stream] v6-0002-Support-load-balancing-in-libpq.patch (28.7K, ../DBBPR83MB05079A565E6AB609104D3F9DF7FE9@DBBPR83MB0507.EURPRD83.prod.outlook.com/3-v6-0002-Support-load-balancing-in-libpq.patch)
download | inline diff:
From 83d0abde7db0ddd07f62521c15812f73827f3d61 Mon Sep 17 00:00:00 2001
From: Jelte Fennema <[email protected]>
Date: Mon, 12 Sep 2022 09:44:06 +0200
Subject: [PATCH v6 2/2] Support load balancing in libpq
This adds support for load balancing to libpq using the newly added
load_balance_hosts parameter. When setting the load_balance_hosts
parameter to random, hosts and addresses will be connected to in a
random order. This then results in load balancing across these
hosts/addresses if multiple clients do this at the same time.
This patch implements two levels of random load balancing:
1. The given hosts are randomly shuffled, before resolving them
one-by-one.
2. Once a host its addresses get resolved, those addresses are shuffled,
before trying to connect to them one-by-one.
---
.cirrus.yml | 14 ++
doc/src/sgml/libpq.sgml | 69 +++++++
src/include/libpq/pqcomm.h | 6 +
src/interfaces/libpq/fe-connect.c | 215 ++++++++++++++++++----
src/interfaces/libpq/libpq-int.h | 21 ++-
src/interfaces/libpq/meson.build | 1 +
src/interfaces/libpq/t/003_loadbalance.pl | 167 +++++++++++++++++
7 files changed, 460 insertions(+), 33 deletions(-)
create mode 100644 src/interfaces/libpq/t/003_loadbalance.pl
diff --git a/.cirrus.yml b/.cirrus.yml
index 69837bcd5a..f71e93451f 100644
--- a/.cirrus.yml
+++ b/.cirrus.yml
@@ -308,6 +308,14 @@ task:
mkdir -m 770 /tmp/cores
chown root:postgres /tmp/cores
sysctl kernel.core_pattern='/tmp/cores/%e-%s-%p.core'
+
+ setup_hosts_file_script: |
+ cat >> /etc/hosts <<-EOF
+ 127.0.0.1 pg-loadbalancetest
+ 127.0.0.2 pg-loadbalancetest
+ 127.0.0.3 pg-loadbalancetest
+ EOF
+
setup_additional_packages_script: |
#apt-get update
#DEBIAN_FRONTEND=noninteractive apt-get -y install ...
@@ -557,6 +565,12 @@ task:
setup_additional_packages_script: |
REM choco install -y --no-progress ...
+ setup_hosts_file_script: |
+ echo 127.0.0.1 pg-loadbalancetest >> c:\Windows\System32\Drivers\etc\hosts
+ echo 127.0.0.2 pg-loadbalancetest >> c:\Windows\System32\Drivers\etc\hosts
+ echo 127.0.0.3 pg-loadbalancetest >> c:\Windows\System32\Drivers\etc\hosts
+ type c:\Windows\System32\Drivers\etc\hosts
+
# Use /DEBUG:FASTLINK to avoid high memory usage during linking
configure_script: |
vcvarsall x64
diff --git a/doc/src/sgml/libpq.sgml b/doc/src/sgml/libpq.sgml
index af278660eb..03eab1d02e 100644
--- a/doc/src/sgml/libpq.sgml
+++ b/doc/src/sgml/libpq.sgml
@@ -1964,6 +1964,75 @@ postgresql://%2Fvar%2Flib%2Fpostgresql/dbname
</para>
</listitem>
</varlistentry>
+
+ <varlistentry id="libpq-connect-load-balance-hosts" xreflabel="load_balance_hosts">
+ <term><literal>load_balance_hosts</literal></term>
+ <listitem>
+ <para>
+ Controls the order in which the client tries to connect to the available
+ hosts and addresses. It's typically used in combination with multiple
+ host names or a DNS record that returns multiple IPs. This parameter be
+ used in combination with <xref linkend="libpq-connect-target-session-attrs"/>
+ to, for example, load balance over stanby servers only. Once successfully
+ connected, subsequent queries on the returned connection will all be
+ sent to the same server. There are currently two modes:
+ <variablelist>
+ <varlistentry>
+ <term><literal>disable</literal> (default)</term>
+ <listitem>
+ <para>
+ Hosts are tried in the order in which they are provided and
+ addresses are tried in the order they are received from DNS or a
+ hosts file.
+ </para>
+ </listitem>
+ </varlistentry>
+
+ <varlistentry>
+ <term><literal>random</literal></term>
+ <listitem>
+ <para>
+ The provided hosts and the addresses that they resolve to are
+ tried in random order. This value is mostly useful when opening
+ multiple connections at the same time, possibly from different
+ machines. This way connections can be load balanced across multiple
+ Postgres servers.
+ </para>
+ <para>
+ This algorithm uses two levels of random choices: First the hosts
+ will be resolved in random order. Then before resolving the next
+ host, all resolved addresses for the current host will be tried in
+ random order. This behaviour can lead to non-uniform address
+ selection in certain cases, for instance when some hosts resolve to
+ more addresses than others. So if you want uniform load balancing,
+ this is something to keep in mind. However, non-uniform load
+ balancing also can be used to your advantage, e.g. by providing the
+ hostname of a larger server multiple times in the host string so it
+ gets more connections.
+ </para>
+ <para>
+ When using this value it's recommended to also configure a reasonable
+ value for <xref linkend="libpq-connect-connect-timeout"/>. Because then,
+ if one of the nodes that are used for load balancing is not responding,
+ a new node will be tried.
+ </para>
+ </listitem>
+ </varlistentry>
+ </variablelist>
+ </para>
+ </listitem>
+ </varlistentry>
+
+ <varlistentry id="libpq-random-seed" xreflabel="random_seed">
+ <term><literal>random_seed</literal></term>
+ <listitem>
+ <para>
+ Sets the random seed that is used by <xref linkend="libpq-connect-load-balance-hosts"/>
+ to randomize the host order. This option is mostly useful when running
+ tests that require a stable random order.
+ </para>
+ </listitem>
+ </varlistentry>
</variablelist>
</para>
</sect2>
diff --git a/src/include/libpq/pqcomm.h b/src/include/libpq/pqcomm.h
index 66ba359390..ee28e223bd 100644
--- a/src/include/libpq/pqcomm.h
+++ b/src/include/libpq/pqcomm.h
@@ -27,6 +27,12 @@ typedef struct
socklen_t salen;
} SockAddr;
+typedef struct
+{
+ int family;
+ SockAddr addr;
+} AddrInfo;
+
/* Configure the UNIX socket location for the well known port. */
#define UNIXSOCK_PATH(path, port, sockdir) \
diff --git a/src/interfaces/libpq/fe-connect.c b/src/interfaces/libpq/fe-connect.c
index 773e9e1f3a..18a07d810d 100644
--- a/src/interfaces/libpq/fe-connect.c
+++ b/src/interfaces/libpq/fe-connect.c
@@ -123,6 +123,7 @@ static int ldapServiceLookup(const char *purl, PQconninfoOption *options,
#define DefaultChannelBinding "disable"
#endif
#define DefaultTargetSessionAttrs "any"
+#define DefaultLoadBalanceHosts "disable"
#ifdef USE_SSL
#define DefaultSSLMode "prefer"
#else
@@ -341,6 +342,15 @@ static const internalPQconninfoOption PQconninfoOptions[] = {
"Target-Session-Attrs", "", 15, /* sizeof("prefer-standby") = 15 */
offsetof(struct pg_conn, target_session_attrs)},
+ {"load_balance_hosts", "PGLOADBALANCEHOSTS",
+ DefaultLoadBalanceHosts, NULL,
+ "Load-Balance-Hosts", "", 8, /* sizeof("disable") = 8 */
+ offsetof(struct pg_conn, load_balance_hosts)},
+
+ {"random_seed", NULL, NULL, NULL,
+ "Random-Seed", "", 10, /* strlen(INT32_MAX) == 10 */
+ offsetof(struct pg_conn, randomseed)},
+
/* Terminating entry --- MUST BE LAST */
{NULL, NULL, NULL, NULL,
NULL, NULL, 0}
@@ -379,6 +389,7 @@ static bool fillPGconn(PGconn *conn, PQconninfoOption *connOptions);
static void freePGconn(PGconn *conn);
static void closePGconn(PGconn *conn);
static void release_conn_addrinfo(PGconn *conn);
+static bool store_conn_addrinfo(PGconn *conn, struct addrinfo *addrlist);
static void sendTerminateConn(PGconn *conn);
static PQconninfoOption *conninfo_init(PQExpBuffer errorMessage);
static PQconninfoOption *parse_connection_string(const char *connstr,
@@ -424,6 +435,8 @@ static void pgpassfileWarning(PGconn *conn);
static void default_threadlock(int acquire);
static bool sslVerifyProtocolVersion(const char *version);
static bool sslVerifyProtocolRange(const char *min, const char *max);
+static bool parse_int_param(const char *value, int *result, PGconn *conn,
+ const char *context);
/* global variable because fe-auth.c needs to access it */
@@ -1007,6 +1020,44 @@ parse_comma_separated_list(char **startptr, bool *more)
return p;
}
+/*
+ * Initializes the prng_state field of the connection. We want something
+ * unpredictable, so if possible, use high-quality random bits for the
+ * seed. Otherwise, fall back to a seed based on timestamp and PID.
+ */
+static bool
+libpq_prng_init(PGconn *conn)
+{
+ if (unlikely(conn->randomseed))
+ {
+ int rseed;
+
+ if (!parse_int_param(conn->randomseed, &rseed, conn, "random_seed"))
+ return false;
+
+ pg_prng_seed(&conn->prng_state, rseed);
+ }
+ else if (unlikely(!pg_prng_strong_seed(&conn->prng_state)))
+ {
+ uint64 rseed;
+ time_t now = time(NULL);
+
+ /*
+ * Since PIDs and timestamps tend to change more frequently in their
+ * least significant bits, shift the timestamp left to allow a larger
+ * total number of seeds in a given time period. Since that would
+ * leave only 20 bits of the timestamp that cycle every ~1 second,
+ * also mix in some higher bits.
+ */
+ rseed = ((uint64) getpid()) ^
+ ((uint64) now << 12) ^
+ ((uint64) now >> 20);
+
+ pg_prng_seed(&conn->prng_state, rseed);
+ }
+ return true;
+}
+
/*
* connectOptions2
*
@@ -1400,6 +1451,47 @@ connectOptions2(PGconn *conn)
else
conn->target_server_type = SERVER_TYPE_ANY;
+ /*
+ * validate load_balance_hosts option, and set load_balance_type
+ */
+ if (conn->load_balance_hosts)
+ {
+ if (strcmp(conn->load_balance_hosts, "disable") == 0)
+ conn->load_balance_type = LOAD_BALANCE_DISABLE;
+ else if (strcmp(conn->load_balance_hosts, "random") == 0)
+ conn->load_balance_type = LOAD_BALANCE_RANDOM;
+ else
+ {
+ conn->status = CONNECTION_BAD;
+ libpq_append_conn_error(conn, "invalid %s value: \"%s\"",
+ "load_balance_hosts",
+ conn->load_balance_hosts);
+ return false;
+ }
+ }
+ else
+ conn->load_balance_type = LOAD_BALANCE_DISABLE;
+
+ if (conn->load_balance_type == LOAD_BALANCE_RANDOM)
+ {
+ if (!libpq_prng_init(conn))
+ return false;
+
+ /*
+ * Shuffle connhost with a Durstenfeld/Knuth version of the
+ * Fisher-Yates shuffle. Source:
+ * https://en.wikipedia.org/wiki/Fisher%E2%80%93Yates_shuffle#The_modern_algorithm
+ */
+ for (i = conn->nconnhost - 1; i > 0; i--)
+ {
+ int j = pg_prng_uint64_range(&conn->prng_state, 0, i);
+ pg_conn_host temp = conn->connhost[j];
+
+ conn->connhost[j] = conn->connhost[i];
+ conn->connhost[i] = temp;
+ }
+ }
+
/*
* Resolve special "auto" client_encoding from the locale
*/
@@ -2077,7 +2169,7 @@ connectDBComplete(PGconn *conn)
time_t finish_time = ((time_t) -1);
int timeout = 0;
int last_whichhost = -2; /* certainly different from whichhost */
- struct addrinfo *last_addr_cur = NULL;
+ int last_whichaddr = -2; /* certainly different from whichaddr */
if (conn == NULL || conn->status == CONNECTION_BAD)
return 0;
@@ -2121,11 +2213,11 @@ connectDBComplete(PGconn *conn)
if (flag != PGRES_POLLING_OK &&
timeout > 0 &&
(conn->whichhost != last_whichhost ||
- conn->addr_cur != last_addr_cur))
+ conn->whichaddr != last_whichaddr))
{
finish_time = time(NULL) + timeout;
last_whichhost = conn->whichhost;
- last_addr_cur = conn->addr_cur;
+ last_whichaddr = conn->whichaddr;
}
/*
@@ -2272,9 +2364,9 @@ keep_going: /* We will come back to here until there is
/* Time to advance to next address, or next host if no more addresses? */
if (conn->try_next_addr)
{
- if (conn->addr_cur && conn->addr_cur->ai_next)
+ if (conn->whichaddr < conn->naddr)
{
- conn->addr_cur = conn->addr_cur->ai_next;
+ conn->whichaddr++;
reset_connection_state_machine = true;
}
else
@@ -2287,6 +2379,7 @@ keep_going: /* We will come back to here until there is
{
pg_conn_host *ch;
struct addrinfo hint;
+ struct addrinfo *addrlist;
int thisport;
int ret;
char portstr[MAXPGPATH];
@@ -2327,7 +2420,7 @@ keep_going: /* We will come back to here until there is
/* Initialize hint structure */
MemSet(&hint, 0, sizeof(hint));
hint.ai_socktype = SOCK_STREAM;
- conn->addrlist_family = hint.ai_family = AF_UNSPEC;
+ hint.ai_family = AF_UNSPEC;
/* Figure out the port number we're going to use. */
if (ch->port == NULL || ch->port[0] == '\0')
@@ -2350,8 +2443,8 @@ keep_going: /* We will come back to here until there is
{
case CHT_HOST_NAME:
ret = pg_getaddrinfo_all(ch->host, portstr, &hint,
- &conn->addrlist);
- if (ret || !conn->addrlist)
+ &addrlist);
+ if (ret || !addrlist)
{
libpq_append_conn_error(conn, "could not translate host name \"%s\" to address: %s",
ch->host, gai_strerror(ret));
@@ -2362,8 +2455,8 @@ keep_going: /* We will come back to here until there is
case CHT_HOST_ADDRESS:
hint.ai_flags = AI_NUMERICHOST;
ret = pg_getaddrinfo_all(ch->hostaddr, portstr, &hint,
- &conn->addrlist);
- if (ret || !conn->addrlist)
+ &addrlist);
+ if (ret || !addrlist)
{
libpq_append_conn_error(conn, "could not parse network address \"%s\": %s",
ch->hostaddr, gai_strerror(ret));
@@ -2372,7 +2465,7 @@ keep_going: /* We will come back to here until there is
break;
case CHT_UNIX_SOCKET:
- conn->addrlist_family = hint.ai_family = AF_UNIX;
+ hint.ai_family = AF_UNIX;
UNIXSOCK_PATH(portstr, thisport, ch->host);
if (strlen(portstr) >= UNIXSOCK_PATH_BUFLEN)
{
@@ -2387,8 +2480,8 @@ keep_going: /* We will come back to here until there is
* name as a Unix-domain socket path.
*/
ret = pg_getaddrinfo_all(NULL, portstr, &hint,
- &conn->addrlist);
- if (ret || !conn->addrlist)
+ &addrlist);
+ if (ret || !addrlist)
{
libpq_append_conn_error(conn, "could not translate Unix-domain socket path \"%s\" to address: %s",
portstr, gai_strerror(ret));
@@ -2397,8 +2490,14 @@ keep_going: /* We will come back to here until there is
break;
}
- /* OK, scan this addrlist for a working server address */
- conn->addr_cur = conn->addrlist;
+ if (!store_conn_addrinfo(conn, addrlist))
+ {
+ pg_freeaddrinfo_all(hint.ai_family, addrlist);
+ libpq_append_conn_error(conn, "out of memory");
+ goto error_return;
+ }
+ pg_freeaddrinfo_all(hint.ai_family, addrlist);
+
reset_connection_state_machine = true;
conn->try_next_host = false;
}
@@ -2455,30 +2554,29 @@ keep_going: /* We will come back to here until there is
{
/*
* Try to initiate a connection to one of the addresses
- * returned by pg_getaddrinfo_all(). conn->addr_cur is the
+ * returned by pg_getaddrinfo_all(). conn->whichaddr is the
* next one to try.
*
* The extra level of braces here is historical. It's not
* worth reindenting this whole switch case to remove 'em.
*/
{
- struct addrinfo *addr_cur = conn->addr_cur;
char host_addr[NI_MAXHOST];
+ AddrInfo *addr_cur;
/*
* Advance to next possible host, if we've tried all of
* the addresses for the current host.
*/
- if (addr_cur == NULL)
+ if (conn->whichaddr == conn->naddr)
{
conn->try_next_host = true;
goto keep_going;
}
+ addr_cur = &conn->addr[conn->whichaddr];
/* Remember current address for possible use later */
- memcpy(&conn->raddr.addr, addr_cur->ai_addr,
- addr_cur->ai_addrlen);
- conn->raddr.salen = addr_cur->ai_addrlen;
+ memcpy(&conn->raddr, &addr_cur->addr, sizeof(SockAddr));
/*
* Set connip, too. Note we purposely ignore strdup
@@ -2494,7 +2592,7 @@ keep_going: /* We will come back to here until there is
conn->connip = strdup(host_addr);
/* Try to create the socket */
- conn->sock = socket(addr_cur->ai_family, SOCK_STREAM, 0);
+ conn->sock = socket(addr_cur->family, SOCK_STREAM, 0);
if (conn->sock == PGINVALID_SOCKET)
{
int errorno = SOCK_ERRNO;
@@ -2505,7 +2603,7 @@ keep_going: /* We will come back to here until there is
* cases where the address list includes both IPv4 and
* IPv6 but kernel only accepts one family.
*/
- if (addr_cur->ai_next != NULL ||
+ if (conn->whichaddr < conn->naddr ||
conn->whichhost + 1 < conn->nconnhost)
{
conn->try_next_addr = true;
@@ -2531,7 +2629,7 @@ keep_going: /* We will come back to here until there is
* TCP sockets, nonblock mode, close-on-exec. Try the
* next address if any of this fails.
*/
- if (addr_cur->ai_family != AF_UNIX)
+ if (addr_cur->family != AF_UNIX)
{
if (!connectNoDelay(conn))
{
@@ -2558,7 +2656,7 @@ keep_going: /* We will come back to here until there is
}
#endif /* F_SETFD */
- if (addr_cur->ai_family != AF_UNIX)
+ if (addr_cur->family != AF_UNIX)
{
#ifndef WIN32
int on = 1;
@@ -2650,8 +2748,8 @@ keep_going: /* We will come back to here until there is
* Start/make connection. This should not block, since we
* are in nonblock mode. If it does, well, too bad.
*/
- if (connect(conn->sock, addr_cur->ai_addr,
- addr_cur->ai_addrlen) < 0)
+ if (connect(conn->sock, (struct sockaddr *) &addr_cur->addr.addr,
+ addr_cur->addr.salen) < 0)
{
if (SOCK_ERRNO == EINPROGRESS ||
#ifdef WIN32
@@ -4035,12 +4133,68 @@ freePGconn(PGconn *conn)
free(conn->outBuffer);
free(conn->rowBuf);
free(conn->target_session_attrs);
+ free(conn->load_balance_hosts);
+ free(conn->randomseed);
termPQExpBuffer(&conn->errorMessage);
termPQExpBuffer(&conn->workBuffer);
free(conn);
}
+/*
+ * Copies over the AddrInfos from addrlist to the PGconn.
+ */
+static bool
+store_conn_addrinfo(PGconn *conn, struct addrinfo *addrlist)
+{
+ struct addrinfo *ai = addrlist;
+
+ conn->whichaddr = 0;
+
+ conn->naddr = 0;
+ while (ai)
+ {
+ ai = ai->ai_next;
+ conn->naddr++;
+ }
+
+ conn->addr = calloc(conn->naddr, sizeof(AddrInfo));
+ if (conn->addr == NULL)
+ return false;
+
+ ai = addrlist;
+ for (int i = 0; i < conn->naddr; i++)
+ {
+ conn->addr[i].family = ai->ai_family;
+
+ memcpy(&conn->addr[i].addr.addr, ai->ai_addr,
+ ai->ai_addrlen);
+ conn->addr[i].addr.salen = ai->ai_addrlen;
+ ai = ai->ai_next;
+ }
+
+ if (conn->load_balance_type == LOAD_BALANCE_RANDOM)
+ {
+ /*
+ * Shuffle addr with a Durstenfeld/Knuth version of the Fisher-Yates
+ * shuffle. Source:
+ * https://en.wikipedia.org/wiki/Fisher%E2%80%93Yates_shuffle#The_modern_algorithm
+ *
+ * We don't need to initialize conn->prng_state here, because that
+ * already happened in connectOptions2.
+ */
+ for (int i = conn->naddr - 1; i > 0; i--)
+ {
+ int j = pg_prng_uint64_range(&conn->prng_state, 0, i);
+ AddrInfo temp = conn->addr[j];
+
+ conn->addr[j] = conn->addr[i];
+ conn->addr[i] = temp;
+ }
+ }
+ return true;
+}
+
/*
* release_conn_addrinfo
* - Free any addrinfo list in the PGconn.
@@ -4048,11 +4202,10 @@ freePGconn(PGconn *conn)
static void
release_conn_addrinfo(PGconn *conn)
{
- if (conn->addrlist)
+ if (conn->addr)
{
- pg_freeaddrinfo_all(conn->addrlist_family, conn->addrlist);
- conn->addrlist = NULL;
- conn->addr_cur = NULL; /* for safety */
+ free(conn->addr);
+ conn->addr = NULL;
}
}
diff --git a/src/interfaces/libpq/libpq-int.h b/src/interfaces/libpq/libpq-int.h
index 712d572373..86dd1d6d40 100644
--- a/src/interfaces/libpq/libpq-int.h
+++ b/src/interfaces/libpq/libpq-int.h
@@ -82,6 +82,8 @@ typedef struct
#endif
#endif /* USE_OPENSSL */
+#include "common/pg_prng.h"
+
/*
* POSTGRES backend dependent Constants.
*/
@@ -242,6 +244,13 @@ typedef enum
SERVER_TYPE_PREFER_STANDBY_PASS2 /* second pass - behaves same as ANY */
} PGTargetServerType;
+/* Target server type (decoded value of load_balance_hosts) */
+typedef enum
+{
+ LOAD_BALANCE_DISABLE = 0, /* Use the existing host order (default) */
+ LOAD_BALANCE_RANDOM, /* Read-write server */
+} PGLoadBalanceType;
+
/* Boolean value plus a not-known state, for GUCs we might have to fetch */
typedef enum
{
@@ -396,6 +405,8 @@ struct pg_conn
char *ssl_min_protocol_version; /* minimum TLS protocol version */
char *ssl_max_protocol_version; /* maximum TLS protocol version */
char *target_session_attrs; /* desired session properties */
+ char *load_balance_hosts; /* load balance over hosts */
+ char *randomseed; /* seed for randomization of load balancing */
/* Optional file to write trace info to */
FILE *Pfdebug;
@@ -459,10 +470,14 @@ struct pg_conn
/* Transient state needed while establishing connection */
PGTargetServerType target_server_type; /* desired session properties */
+ PGLoadBalanceType load_balance_type; /* desired load balancing
+ * algorithm */
bool try_next_addr; /* time to advance to next address/host? */
bool try_next_host; /* time to advance to next connhost[]? */
- struct addrinfo *addrlist; /* list of addresses for current connhost */
- struct addrinfo *addr_cur; /* the one currently being tried */
+ int naddr; /* number of addresses returned by getaddrinfo */
+ int whichaddr; /* the address currently being tried */
+ AddrInfo *addr; /* the array of addresses for the currently
+ * tried host */
int addrlist_family; /* needed to know how to free addrlist */
bool send_appname; /* okay to send application_name? */
@@ -477,6 +492,8 @@ struct pg_conn
PGVerbosity verbosity; /* error/notice message verbosity */
PGContextVisibility show_context; /* whether to show CONTEXT field */
PGlobjfuncs *lobjfuncs; /* private state for large-object access fns */
+ pg_prng_state prng_state; /* prng state for load balancing connections */
+
/* Buffer for data received from backend and not yet processed */
char *inBuffer; /* currently allocated buffer */
diff --git a/src/interfaces/libpq/meson.build b/src/interfaces/libpq/meson.build
index 573fd9b6ea..52b327500c 100644
--- a/src/interfaces/libpq/meson.build
+++ b/src/interfaces/libpq/meson.build
@@ -116,6 +116,7 @@ tests += {
'tests': [
't/001_uri.pl',
't/002_api.pl',
+ 't/003_loadbalance.pl',
],
'env': {'with_ssl': get_option('ssl')},
},
diff --git a/src/interfaces/libpq/t/003_loadbalance.pl b/src/interfaces/libpq/t/003_loadbalance.pl
new file mode 100644
index 0000000000..1b4e8fd813
--- /dev/null
+++ b/src/interfaces/libpq/t/003_loadbalance.pl
@@ -0,0 +1,167 @@
+# Copyright (c) 2023, PostgreSQL Global Development Group
+use strict;
+use warnings;
+use Config;
+use PostgreSQL::Test::Utils;
+use PostgreSQL::Test::Cluster;
+use File::Spec::Functions 'catfile';
+use Test::More;
+
+# This tests two different methods of load balancing from libpq
+# 1. Load balancing by providing multiple host and port combinations in the
+# libpq connection string.
+# 2. By using a hosts file where hostname maps to multiple different IP
+# addresses. Regular Postgres users wouldn't usually use such a host file,
+# but this is the easiest way to immitate behaviour of a DNS server that
+# returns multiple IP addresses for the same DNS record.
+#
+# Testing method 1 is supported on all platforms and works out of the box. But
+# testing method 2 has some more requirements, both on the platform and on the
+# initial setup. If any of these requirements are not met, then method 2 is
+# simply not tested.
+#
+# The requirements to test method 2 are as follows:
+# 1. Windows or Linux should be used.
+# 2. The OS hosts file at /etc/hosts or c:\Windows\System32\Drivers\etc\hosts
+# should contain the following contents:
+#
+# 127.0.0.1 pg-loadbalancetest
+# 127.0.0.2 pg-loadbalancetest
+# 127.0.0.3 pg-loadbalancetest
+#
+#
+# Windows or Linux are required to test method 2 because these OSes allow
+# binding to 127.0.0.2 and 127.0.0.3 addresess by default, but other OSes
+# don't. We need to bind to different IP addresses, so that we can use these
+# different IP addresses in the hosts file.
+#
+# The hosts file needs to be prepared before running this test. We don't do it
+# on the fly, because it requires root permissions to change the hosts file. In
+# CI we set up the previously mentioned rules in the hosts file, so that this
+# load balancing method is tested.
+
+
+# Cluster setup which is shared for testing both load balancing methods
+my $can_bind_to_127_0_0_2 = $Config{osname} eq 'linux' || $PostgreSQL::Test::Utils::windows_os;
+
+if ($can_bind_to_127_0_0_2)
+{
+ $PostgreSQL::Test::Cluster::use_tcp = 1;
+ $PostgreSQL::Test::Cluster::test_pghost = '127.0.0.1';
+}
+my $port = PostgreSQL::Test::Cluster::get_free_port();
+my $node1 = PostgreSQL::Test::Cluster->new('node1', port => $port);
+my $node2 = PostgreSQL::Test::Cluster->new('node2', port => $port, own_host => 1);
+my $node3 = PostgreSQL::Test::Cluster->new('node3', port => $port, own_host => 1);
+
+# Create a data directory with initdb
+$node1->init();
+$node2->init();
+$node3->init();
+
+# Start the PostgreSQL server
+$node1->start();
+$node2->start();
+$node3->start();
+
+# Start the tests for load balancing method 1
+my $hostlist = $node1->host . ',' . $node2->host . ',' . $node3->host;
+my $portlist = "$port,$port,$port";
+
+$node1->connect_ok("host=$hostlist port=$portlist load_balance_hosts=random random_seed=123",
+ "seed 123 selects node 1 first",
+ sql => "SELECT 'connect1'",
+ log_like => [qr/statement: SELECT 'connect1'/]);
+
+$node2->connect_ok("host=$hostlist port=$portlist load_balance_hosts=random random_seed=123",
+ "seed 123 does not select node 2 first",
+ sql => "SELECT 'connect1'",
+ log_unlike => [qr/statement: SELECT 'connect1'/]);
+
+$node3->connect_ok("host=$hostlist port=$portlist load_balance_hosts=random random_seed=123",
+ "seed 123 does not select node 3 first",
+ sql => "SELECT 'connect1'",
+ log_unlike => [qr/statement: SELECT 'connect1'/]);
+
+$node3->connect_ok("host=$hostlist port=$portlist load_balance_hosts=random random_seed=42",
+ "seed 42 selects node 3 first",
+ sql => "SELECT 'connect2'",
+ log_like => [qr/statement: SELECT 'connect2'/]);
+
+$node1->connect_ok("host=$hostlist port=$portlist load_balance_hosts=random random_seed=42",
+ "seed 42 does not select node 1 first",
+ sql => "SELECT 'connect2'",
+ log_unlike => [qr/statement: SELECT 'connect2'/]);
+
+$node2->connect_ok("host=$hostlist port=$portlist load_balance_hosts=random random_seed=42",
+ "seed 42 does not select node 2 first",
+ sql => "SELECT 'connect2'",
+ log_unlike => [qr/statement: SELECT 'connect2'/]);
+
+$node3->stop();
+
+$node1->connect_ok("host=$hostlist port=$portlist load_balance_hosts=random random_seed=42",
+ "seed 42 does select node 1 second",
+ sql => "SELECT 'connect3'",
+ log_like => [qr/statement: SELECT 'connect3'/]);
+
+$node2->connect_ok("host=$hostlist port=$portlist load_balance_hosts=random random_seed=42",
+ "seed 42 does not select node 2 second",
+ sql => "SELECT 'connect3'",
+ log_unlike => [qr/statement: SELECT 'connect3'/]);
+
+$node3->start();
+
+# Checks for the requirements for testing load balancing method 2
+if (!$can_bind_to_127_0_0_2) {
+ # The OS requirement is not met
+ done_testing();
+ exit;
+}
+
+my $hosts_path;
+if ($windows_os) {
+ $hosts_path = 'c:\Windows\System32\Drivers\etc\hosts';
+}
+else
+{
+ $hosts_path = '/etc/hosts';
+}
+
+my $hosts_content = PostgreSQL::Test::Utils::slurp_file($hosts_path);
+
+if ($hosts_content !~ m/pg-loadbalancetest/) {
+ # Host file is not prepared for this test
+ done_testing();
+ exit;
+}
+
+# Start the tests for load balancing method 2
+$node2->connect_ok("host=pg-loadbalancetest port=$port load_balance_hosts=random random_seed=44",
+ "seed 44 selects node 2 first",
+ sql => "SELECT 'connect4'",
+ log_like => [qr/statement: SELECT 'connect4'/]);
+
+$node1->connect_ok("host=pg-loadbalancetest port=$port load_balance_hosts=random random_seed=44",
+ "seed 44 does not select node 1 first",
+ sql => "SELECT 'connect4'",
+ log_unlike => [qr/statement: SELECT 'connect4'/]);
+
+$node3->connect_ok("host=pg-loadbalancetest port=$port load_balance_hosts=random random_seed=44",
+ "seed 44 does not select node 3 first",
+ sql => "SELECT 'connect4'",
+ log_unlike => [qr/statement: SELECT 'connect4'/]);
+
+$node2->stop();
+
+$node1->connect_ok("host=pg-loadbalancetest port=$port load_balance_hosts=random random_seed=44",
+ "seed 44 does select node 1 second",
+ sql => "SELECT 'connect5'",
+ log_like => [qr/statement: SELECT 'connect5'/]);
+
+$node3->connect_ok("host=pg-loadbalancetest port=$port load_balance_hosts=random random_seed=44",
+ "seed 44 does not select node 3 second",
+ sql => "SELECT 'connect5'",
+ log_unlike => [qr/statement: SELECT 'connect5'/]);
+
+done_testing();
--
2.34.1
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Subject: Re: [EXTERNAL] Re: Support load balancing in libpq
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