Re: Request: pg_cancel_backend variant that handles 'idle in transaction' sessions - Mailing list pgsql-hackers

From Amit Kapila
Subject Re: Request: pg_cancel_backend variant that handles 'idle in transaction' sessions
Date
Msg-id CAA4eK1KACVQF+ETXRQq3kXno9OOfWk4wrfnQJ51wPzVyJ_T7Zg@mail.gmail.com
Whole thread Raw
In response to Re: Request: pg_cancel_backend variant that handles 'idle in transaction' sessions  (Merlin Moncure <mmoncure@gmail.com>)
List pgsql-hackers
On Wed, Nov 4, 2015 at 8:06 PM, Merlin Moncure <mmoncure@gmail.com> wrote:
>
> On Tue, Nov 3, 2015 at 10:33 PM, Amit Kapila <amit.kapila16@gmail.com> wrote:
> >>>> It is 100% true. But the users can do strange things. If we solve idle
> >>>> transactions and not idle session, then they are able to increase
> >>>> max_connections to thousands with happy smile in face.
> >>>>
> >>>> I have not strong idea about how to solve it well - maybe introduce
> >>>> transaction_idle_timeout and session_idle_timeout?
> >>>>
> >>>
> >>> What exactly do we want to define session_idle_timeout?  Some
> >>> possibilities:
> >>> a. Reset the session related variables like transaction, prepared
> >>> statements, etc. and retain it for connection pool kind of stuff
> >>> b. Exit from the session
> >>
> >>
> >> b is safe state - and currently it is only one state, that we can forward
> >> to client side (with keep_alive packets) - so I prefer b
> >>
> >
> > Okay, I think one more point to consider is that it would be preferable to
> > have such an option for backend sessions and not for other processes
> > like WalSender.
>
> All right...I see the usage..  I withdraw my objection to 'session'
> prefix then now that I understand the case.  So, do you agree that:
>
> *) session_idle_timeout: dumps the backend after X time in 'idle' state
>

Agreed.

> and
>  *) transaction_timeout: cancels transaction after X time, regardless of state
>

I am not sure about this, let us see if any body else has opinion about
this parameter.



With Regards,
Amit Kapila.
EnterpriseDB: http://www.enterprisedb.com

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