Обсуждение: Idle transactions

Hello, it's been a while that I'm seeing that our servers running JBoss
with PostgreSQL, after some hours of work, have at least 70 or more
"<IDLE> in transaction" status for transactions, and this is bogging down
our servers.
Is this normal behaviour? If not, is there anything I can do to prevent
it? Why is it happening? What's a transaction that is "<IDLE> in
transaction" actually really means?

Thanks a lot.

Mateus.

Hi,

it means that a transaction isn't finished (commit/rollback). check your
application for long running operations or programmming errors.

tm

Mateus Interciso schrieb:
> Hello, it's been a while that I'm seeing that our servers running JBoss
> with PostgreSQL, after some hours of work, have at least 70 or more
> "<IDLE> in transaction" status for transactions, and this is bogging down
> our servers.
> Is this normal behaviour? If not, is there anything I can do to prevent
> it? Why is it happening? What's a transaction that is "<IDLE> in
> transaction" actually really means?
>
> Thanks a lot.
>
> Mateus.
>
>
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On Tue, Sep 11, 2007 at 11:15:54AM +0000, Mateus Interciso wrote:

> Hello, it's been a while that I'm seeing that our servers running JBoss
> with PostgreSQL, after some hours of work, have at least 70 or more
> "<IDLE> in transaction" status for transactions, and this is bogging down
> our servers.
> Is this normal behaviour? If not, is there anything I can do to prevent
> it? Why is it happening? What's a transaction that is "<IDLE> in
> transaction" actually really means?

"idle in transaction" means that someone did a "begin", but didn't issue
a "commit" or "rollback" yet. It is often a sign of bad application
design and you should contact the application developers. Since open
transactions may hold locks on tables, the whole application may stop
unexpectedly if transactions are left open.

Another possibility is that you've just got a huge workload, e.g. lots
of concurrent access to the application so that it has to perform a lot
of work, but then you should see SELECT/INSERT/UPDATE/etc. as well, not
only "idle in transaction".

In Java terms, code which uses a transaction should always look like
this:
boolean success = false; // default: roll back, e.g. on Exception
connection.openTransaction();
try
{
  // perform work
  success = true;
}
finally
{
   connection.closeTransaction (success);
}

HTH,

Tino.

--
www.spiritualdesign-chemnitz.de
www.lebensraum11.de

Tino Schwarze * Parkstraße 17h * 09120 Chemnitz

On Tue, 11 Sep 2007 13:39:28 +0200, Tino Schwarze wrote:

> On Tue, Sep 11, 2007 at 11:15:54AM +0000, Mateus Interciso wrote:
>
>> Hello, it's been a while that I'm seeing that our servers running JBoss
>> with PostgreSQL, after some hours of work, have at least 70 or more
>> "<IDLE> in transaction" status for transactions, and this is bogging
>> down our servers.
>> Is this normal behaviour? If not, is there anything I can do to prevent
>> it? Why is it happening? What's a transaction that is "<IDLE> in
>> transaction" actually really means?
>
> "idle in transaction" means that someone did a "begin", but didn't issue
> a "commit" or "rollback" yet. It is often a sign of bad application
> design and you should contact the application developers. Since open
> transactions may hold locks on tables, the whole application may stop
> unexpectedly if transactions are left open.
>
> Another possibility is that you've just got a huge workload, e.g. lots
> of concurrent access to the application so that it has to perform a lot
> of work, but then you should see SELECT/INSERT/UPDATE/etc. as well, not
> only "idle in transaction".
>
> In Java terms, code which uses a transaction should always look like
> this:
> boolean success = false; // default: roll back, e.g. on Exception
> connection.openTransaction();
> try
> {
>   // perform work
>   success = true;
> }
> finally
> {
>    connection.closeTransaction (success);
> }
>
> HTH,
>
> Tino.

Thanks for your reply.
Is there any way on PostgreSQL that I can see the transaction that
haven't been commited?

This would simplify the debugging.

Thanks a lot.

Mateus.

check your jboss log for stack traces.

Mateus Interciso schrieb:
> Thanks for your reply.
> Is there any way on PostgreSQL that I can see the transaction that
> haven't been commited?
>
> This would simplify the debugging.
>
> Thanks a lot.
>
> Mateus.
>
>
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On Tue, 11 Sep 2007 14:33:23 +0200, Thomas Markus wrote:

> check your jboss log for stack traces.
>
> Mateus Interciso schrieb:
>> Thanks for your reply.
>> Is there any way on PostgreSQL that I can see the transaction that
>> haven't been commited?
>>
>> This would simplify the debugging.
>>
>> Thanks a lot.
>>
>> Mateus.
>>
>>
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There's no way to do it on PostgreSQL instead?

On Tue, Sep 11, 2007 at 12:26:18PM +0000, Mateus Interciso wrote:

> Thanks for your reply.
> Is there any way on PostgreSQL that I can see the transaction that
> haven't been commited?

The following queries shows open transactions and locks held by the
transaction.

select c.relname,l.transaction,l.pid,l.granted,l.mode from pg_class
c,pg_locks l where l.relation = c.oid order by l.pid, l.mode;

HTH,

Tino.


--
www.spiritualdesign-chemnitz.de
www.lebensraum11.de

Tino Schwarze * Parkstraße 17h * 09120 Chemnitz