Re: Extraordinarily slow!!

From: Chris Travers <chris(at)travelamericas(dot)com>
To: Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)us>, pgsql-general <pgsql-general(at)postgresql(dot)org>
Subject: Re: Extraordinarily slow!!
Date: 2005-09-28 06:17:02
Message-ID: 433A355E.5090903@travelamericas.com
Views: Raw Message | Whole Thread | Download mbox | Resend email
Thread:
Lists: pgsql-general

Tom Lane wrote:

>"Justin R. Smith" <jsmith(at)drexel(dot)edu> writes:
>
>
>>I've solved the problem.
>>
>>
>
>
>
>>I was accessing Postgres over an ssh connection and had enabled X
>>forwarding in the sshd server (not the default configuration). For
>>reasons that pass understanding, psql attempts to establish an X
>>connection with EACH elementary operation it performs (unless no such
>>connection is possible). It doesn't actually USE this X connection for
>>anything as far as I know, but the attempt to make the connection over a
>>slow communication line creates an enormous delay,
>>
>>
Now this was happening with external commands like create_user and
create_db?

If so, I would expect you have a really weird library issue. In this
case, a stack trace on a hung process might be very informative.

If not, check your PAGER settings (I find that although I normally
prefer less, more is better in this case).

>
>
>
>>Reconfiguring the sshd server to NOT forward X connections solved the
>>problem. Database operations take fractions of a second now...
>>
>>
It still seems likely that you will want to track this down in case
something else is wrong that you only discover later.

>
>
>
>>Interestingly, it does NOT help to have X forwarding turned off only in
>>the client: sshd itself must not do any forwarding.
>>
>>
>
>[ scratches head... ] That makes no sense at all. psql doesn't even
>know what X is, let alone try to open X connections for every database
>operation.
>
>Is it conceivable that the openssl library would do this? That would
>seem pretty broken too.
>
>
>
Something is broken. That is for sure. And it probably isn't
PostgreSQL....

>How are you using ssh to access the database, exactly? Is psql running
>through a tunnel port, or what? What versions of ssl/ssh at each end of
>the connection?
>
> regards, tom lane
>
>---------------------------(end of broadcast)---------------------------
>TIP 3: Have you checked our extensive FAQ?
>
> http://www.postgresql.org/docs/faq
>
>
>
>

In response to

Browse pgsql-general by date

  From Date Subject
Next Message hubert depesz lubaczewski 2005-09-28 07:07:07 database bloat, but vacuums are done, and fsm seems to be setup ok
Previous Message pobox@verysmall.org 2005-09-28 00:20:44 Re: RI_ConstraintTrigger question