Re: Optional message to user when terminating/cancelling backend

Joel Jacobson <joel@trustly.com>

From: Joel Jacobson <joel@trustly.com>
To: Alvaro Herrera <alvherre@2ndquadrant.com>
Cc: Satyanarayana Narlapuram <Satyanarayana.Narlapuram@microsoft.com>, Pavel Stehule <pavel.stehule@gmail.com>, Daniel Gustafsson <daniel@yesql.se>, PostgreSQL mailing lists <pgsql-hackers@postgresql.org>
Date: 2017-06-26T14:15:39Z
Lists: pgsql-hackers
+1

On Tue, Jun 20, 2017 at 8:54 PM, Alvaro Herrera
<alvherre@2ndquadrant.com> wrote:
> Unless you have a lot of users running psql manually, I don't see how
> this is actually very useful or actionable.  What would the user do with
> the information?  Hopefully your users already trust that you'd keep the
> downtime to the minimum possible.

I think this feature would be useful for PgTerminator
(https://github.com/trustly/pgterminator)
a tool which automatically kills unprotected processes that could
potentially be the reason why
>X number of protected important processes have been waiting for >Y seconds.

When I'm guilty of locking this in the production DB and get killed by
PgTerminator,
it would be nice to know the reason, e.g. that it was PgTerminator
that killed me
and what process I was blocking.


Commits

  1. Refactor user-facing SQL functions signalling backends

  2. Introduce 64-bit hash functions with a 64-bit seed.