Re: Terminate the idle sessions

On Fri, Aug 14, 2020 at 1:32 PM Li Japin <japinli(at)hotmail(dot)com> wrote:
>
> On Aug 14, 2020, at 2:15 PM, Bharath Rupireddy <
bharath(dot)rupireddyforpostgres(at)gmail(dot)com> wrote:
>
> I think, since the idle_session_timeout is by default disabled, we
> have no problem. My thought is what if a user enables the
> feature(knowingly or unknowingly) on the remote backend? If the user
> knows about the above scenario, that may be fine. On the other hand,
> either we can always the feature on the remote backend(at the
> beginning of the remote txn, like we set for some other configuration
> settings see - configure_remote_session() in connection.c) or how
> about mentioning the above scenario in this feature documentation?
>
> Though we can disable the idle_session_timeout when using postgres_fdw,
> there still has locally cached connection cache entries when the remote
sessions
> terminated by accident. AFAIK, you have provided a patch to solve this
> problem, and it is in current CF [1].
>
> [1] - https://commitfest.postgresql.org/29/2651/
>

Yes, that solution can retry the cached connections at only the beginning
of the remote txn and not at the middle of the remote txn and that makes
sense as we can not retry connecting to a different remote backend in the
middle of a remote txn.

+1 for disabling the idle_session_timeout feature in case of postgres_fdw.
This can avoid the remote backends to timeout during postgres_fdw usages.

With Regards,
Bharath Rupireddy.
EnterpriseDB: http://www.enterprisedb.com