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* hyper slow after upgrade to 8.1.4
@ 2006-07-12 20:41 Medora Schauer <mschauer@fairfield.com>
2006-07-12 22:06 ` Re: hyper slow after upgrade to 8.1.4 Joshua D. Drake <jd@commandprompt.com>
2006-07-13 02:53 ` Re: hyper slow after upgrade to 8.1.4 Bruno Wolff III <bruno@wolff.to>
0 siblings, 2 replies; 7+ messages in thread
From: Medora Schauer @ 2006-07-12 20:41 UTC (permalink / raw)
To: pgsql-performance
I have just upgraded from 7.3.4 to 8.1.4 and now *all* db access calls
are extremely slow. I didn't need to preserve any old data so at this
point all my tables are empty. Just connecting to a db takes several
seconds.
When I was accidentally linking my app with the 7.3.4 libs but running
the 8.1.4 postmaster everything was fine.
I know I'm not giving much to go on but I'm stumped. Can anyone suggest
how I might track down the cause of this problem?
Medora Schauer
^ permalink raw reply [nested|flat] 7+ messages in thread
* Re: hyper slow after upgrade to 8.1.4
2006-07-12 20:41 hyper slow after upgrade to 8.1.4 Medora Schauer <mschauer@fairfield.com>
@ 2006-07-12 22:06 ` Joshua D. Drake <jd@commandprompt.com>
1 sibling, 0 replies; 7+ messages in thread
From: Joshua D. Drake @ 2006-07-12 22:06 UTC (permalink / raw)
To: pgsql-performance; +Cc: Medora Schauer <mschauer@fairfield.com>
On Wednesday 12 July 2006 13:41, Medora Schauer wrote:
> I have just upgraded from 7.3.4 to 8.1.4 and now *all* db access calls
> are extremely slow. I didn't need to preserve any old data so at this
> point all my tables are empty. Just connecting to a db takes several
> seconds.
>
>
>
> When I was accidentally linking my app with the 7.3.4 libs but running
> the 8.1.4 postmaster everything was fine.
>
>
>
> I know I'm not giving much to go on but I'm stumped. Can anyone suggest
> how I might track down the cause of this problem?
analyze?
Sincerely,
Joshua D. Drake
>
>
>
> Medora Schauer
--
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^ permalink raw reply [nested|flat] 7+ messages in thread
* Re: hyper slow after upgrade to 8.1.4
2006-07-12 20:41 hyper slow after upgrade to 8.1.4 Medora Schauer <mschauer@fairfield.com>
@ 2006-07-13 02:53 ` Bruno Wolff III <bruno@wolff.to>
1 sibling, 0 replies; 7+ messages in thread
From: Bruno Wolff III @ 2006-07-13 02:53 UTC (permalink / raw)
To: Medora Schauer <mschauer@fairfield.com>; +Cc: pgsql-performance
On Wed, Jul 12, 2006 at 15:41:14 -0500,
Medora Schauer <mschauer@fairfield.com> wrote:
> I have just upgraded from 7.3.4 to 8.1.4 and now *all* db access calls
> are extremely slow. I didn't need to preserve any old data so at this
> point all my tables are empty. Just connecting to a db takes several
> seconds.
>
> I know I'm not giving much to go on but I'm stumped. Can anyone suggest
> how I might track down the cause of this problem?
That connections are slow makes me think DNS is worth looking at. It might
be that reverse lookups are timing out.
^ permalink raw reply [nested|flat] 7+ messages in thread
* Re: hyper slow after upgrade to 8.1.4
@ 2006-07-13 13:22 Medora Schauer <mschauer@fairfield.com>
2006-07-13 13:54 ` Re: hyper slow after upgrade to 8.1.4 Michael Fuhr <mike@fuhr.org>
0 siblings, 1 reply; 7+ messages in thread
From: Medora Schauer @ 2006-07-13 13:22 UTC (permalink / raw)
To: Bruno Wolff III <bruno@wolff.to>; +Cc: pgsql-performance
> From: Bruno Wolff III [mailto:bruno@wolff.to]
> Sent: Wednesday, July 12, 2006 8:54 PM
> To: Medora Schauer
> Cc: postgresql
> Subject: Re: hyper slow after upgrade to 8.1.4
>
> On Wed, Jul 12, 2006 at 15:41:14 -0500,
> Medora Schauer <mschauer@fairfield.com> wrote:
> > I have just upgraded from 7.3.4 to 8.1.4 and now *all* db access
calls
> > are extremely slow. I didn't need to preserve any old data so at
this
> > point all my tables are empty. Just connecting to a db takes
several
> > seconds.
> >
> > I know I'm not giving much to go on but I'm stumped. Can anyone
suggest
> > how I might track down the cause of this problem?
>
> That connections are slow makes me think DNS is worth looking at. It
might
> be that reverse lookups are timing out.
It does seem to be network related. Using the 8.1.4 psql on a machine
other than the db server connecting to a database takes ~11 secs. Using
it on the db server the connection is virtually instantaneous. Using
the 7.3.4 psql (still the 8.1.4 postmaster) the connection is fast
regardless of what machine I am on.
The pg.log contains the following at the top:
LOG: could not create IPv6 socket: Address family not supported by
protocol
I am using a 2.4.25 linux kernel. For reasons I can't get into I have
no choice but to use this kernel. The config utility for the kernel
shows support for the IPv6 protocol as "experimental" and is not
included in my current build. I can try building a kernel that includes
IPv6 but the "experimental" caveat is scary.
Can it be that the connection delay is because first an IPv6 socket is
trying to be established and when that fails an IPv4 socket is created?
If so, is there any way to make 8.1.4 use only IPv4 sockets?
BTW - The slowness seems to be only during db connection. Once the
connection is established queries seem to execute in a timely manner.
Medora
^ permalink raw reply [nested|flat] 7+ messages in thread
* Re: hyper slow after upgrade to 8.1.4
2006-07-13 13:22 Re: hyper slow after upgrade to 8.1.4 Medora Schauer <mschauer@fairfield.com>
@ 2006-07-13 13:54 ` Michael Fuhr <mike@fuhr.org>
2006-07-13 17:11 ` Re: hyper slow after upgrade to 8.1.4 Tom Lane <tgl@sss.pgh.pa.us>
0 siblings, 1 reply; 7+ messages in thread
From: Michael Fuhr @ 2006-07-13 13:54 UTC (permalink / raw)
To: Medora Schauer <mschauer@fairfield.com>; +Cc: Bruno Wolff III <bruno@wolff.to>; pgsql-performance
On Thu, Jul 13, 2006 at 08:22:46AM -0500, Medora Schauer wrote:
> Can it be that the connection delay is because first an IPv6 socket is
> trying to be established and when that fails an IPv4 socket is created?
A sniffer like tcpdump or ethereal might reveal why connecting is
so slow. The problem might be with DNS queries for AAAA (IPv6)
records prior to queries for A (IPv4) records; see this thread from
almost a year ago:
http://archives.postgresql.org/pgsql-general/2005-08/msg00216.php
--
Michael Fuhr
^ permalink raw reply [nested|flat] 7+ messages in thread
* Re: hyper slow after upgrade to 8.1.4
2006-07-13 13:22 Re: hyper slow after upgrade to 8.1.4 Medora Schauer <mschauer@fairfield.com>
2006-07-13 13:54 ` Re: hyper slow after upgrade to 8.1.4 Michael Fuhr <mike@fuhr.org>
@ 2006-07-13 17:11 ` Tom Lane <tgl@sss.pgh.pa.us>
0 siblings, 0 replies; 7+ messages in thread
From: Tom Lane @ 2006-07-13 17:11 UTC (permalink / raw)
To: Michael Fuhr <mike@fuhr.org>; +Cc: Medora Schauer <mschauer@fairfield.com>; Bruno Wolff III <bruno@wolff.to>; pgsql-performance
Michael Fuhr <mike@fuhr.org> writes:
> On Thu, Jul 13, 2006 at 08:22:46AM -0500, Medora Schauer wrote:
>> Can it be that the connection delay is because first an IPv6 socket is
>> trying to be established and when that fails an IPv4 socket is created?
> A sniffer like tcpdump or ethereal might reveal why connecting is
> so slow.
I'd try strace'ing the client process first --- whatever is slow might
not be exposed as TCP traffic. It does sound though that the problem
is related to userland expecting IPv6 support that the kernel doesn't
actually have.
regards, tom lane
^ permalink raw reply [nested|flat] 7+ messages in thread
* Re: hyper slow after upgrade to 8.1.4
@ 2006-07-13 18:25 Medora Schauer <mschauer@fairfield.com>
0 siblings, 0 replies; 7+ messages in thread
From: Medora Schauer @ 2006-07-13 18:25 UTC (permalink / raw)
To: Tom Lane <tgl@sss.pgh.pa.us>; Michael Fuhr <mike@fuhr.org>; +Cc: Bruno Wolff III <bruno@wolff.to>; pgsql-performance
> From: Tom Lane [mailto:tgl@sss.pgh.pa.us]
> Sent: Thursday, July 13, 2006 11:12 AM
>
> Michael Fuhr <mike@fuhr.org> writes:
> > On Thu, Jul 13, 2006 at 08:22:46AM -0500, Medora Schauer wrote:
> >> Can it be that the connection delay is because first an IPv6 socket
is
> >> trying to be established and when that fails an IPv4 socket is
created?
>
> > A sniffer like tcpdump or ethereal might reveal why connecting is
> > so slow.
>
> I'd try strace'ing the client process first --- whatever is slow might
> not be exposed as TCP traffic. It does sound though that the problem
> is related to userland expecting IPv6 support that the kernel doesn't
> actually have.
>
> regards, tom lane
Good idea Tom. Strace showed communications with a machine that didn't
make sense. Turns out someone had configured DNS on the "slow" machine
but the DNS server wasn't running. When I use the IP address of the PG
server rather than the name with psql, the connection is made quickly.
Thanks for all the help everyone,
Medora Schauer
^ permalink raw reply [nested|flat] 7+ messages in thread
end of thread, other threads:[~2006-07-13 18:25 UTC | newest]
Thread overview: 7+ messages (download: mbox mbox.gz follow: Atom feed)
-- links below jump to the message on this page --
2006-07-12 20:41 hyper slow after upgrade to 8.1.4 Medora Schauer <mschauer@fairfield.com>
2006-07-12 22:06 ` Joshua D. Drake <jd@commandprompt.com>
2006-07-13 02:53 ` Bruno Wolff III <bruno@wolff.to>
2006-07-13 13:22 Re: hyper slow after upgrade to 8.1.4 Medora Schauer <mschauer@fairfield.com>
2006-07-13 13:54 ` Michael Fuhr <mike@fuhr.org>
2006-07-13 17:11 ` Tom Lane <tgl@sss.pgh.pa.us>
2006-07-13 18:25 Re: hyper slow after upgrade to 8.1.4 Medora Schauer <mschauer@fairfield.com>
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