Re: Terminate the idle sessions

Japin Li <japinli@hotmail.com>

From: Li Japin <japinli@hotmail.com>
To: "David G. Johnston" <david.g.johnston@gmail.com>
Cc: "kuroda.hayato@fujitsu.com" <kuroda.hayato@fujitsu.com>, Kyotaro Horiguchi <horikyota.ntt@gmail.com>, Thomas Munro <thomas.munro@gmail.com>, "bharath.rupireddyforpostgres@gmail.com" <bharath.rupireddyforpostgres@gmail.com>, "pgsql-hackers@lists.postgresql.org" <pgsql-hackers@lists.postgresql.org>
Date: 2020-11-17T03:27:05Z
Lists: pgsql-hackers

Attachments

On Nov 17, 2020, at 10:53 AM, David G. Johnston <david.g.johnston@gmail.com<mailto:david.g.johnston@gmail.com>> wrote:

On Monday, November 16, 2020, Li Japin <japinli@hotmail.com<mailto:japinli@hotmail.com>> wrote:

<note>
Consider setting this for specific users instead of as a server default.  Client connections managed by connection poolers, or initiated indirectly like those by a remote postgres_fdw  using server, should probably be excluded from this timeout.

        <note>
         <para>
-         This parameter should be set to zero if you use postgres_fdw or some
-         connection-pooling software, because connections might be closed unexpectedly.
+         This parameter should be set to zero if you use some connection-pooling software, or
+         PostgreSQL servers used by postgres_fdw, because connections might be closed unexpectedly.
         </para>
        </note>


Prefer mine, “or pg servers used by postgres_fdw”, doesn’t flow.

Could you please explain how the idle-in-transaction interfere the long-running stability?

From the docs (next section):

This allows any locks held by that session to be released and the connection slot to be reused; it also allows tuples visible only to this transaction to be vacuumed. See Section 24.1<https://www.postgresql.org/docs/13/routine-vacuuming.html> for more details about this.

Thanks David! Attached.

--
Best regards
Japin Li

Commits

  1. Rethink SQLSTATE code for ERRCODE_IDLE_SESSION_TIMEOUT.

  2. Improve commentary in timeout.c.

  3. Add idle_session_timeout.

  4. Improve timeout.c's handling of repeated timeout set/cancel.