Re: proposal: add 'waiting for replication' to pg_stat_activity.state

On 3 December 2015 at 04:22, Julian Schauder <julian(dot)schauder(at)credativ(dot)de>
wrote:

> I suggest adding a new state to pg_stat_activity.state for backends that
> are
>
waiting for their synchronous commit to be flushed on the remote host.
>
>
Excellent idea. Anything that improves management and visibility into what
the system is doing like this is really valuable.

I notice that you don't set the 'waiting' flag. 'waiting' is presently
documented as:

<entry>True if this backend is currently waiting on a lock</entry>

... but I'm inclined to just widen its definition and set it here, since we
most certainly are waiting, and the column isn't named 'waiting_on_a_lock'.
It shouldn't upset various canned lock monitoring queries people have since
they generally do an inner join on pg_locks anyway.

There are no test changes in this patch, but that's reasonable because we
don't currently have a way to automate tests of sync rep.

I've attached a patch with minor wording/formatting changes, but I think
I'd like to change 'waiting' to true as well. Opinions?

--
Craig Ringer http://www.2ndQuadrant.com/
PostgreSQL Development, 24x7 Support, Training & Services