Re: Add checkpoint and redo LSN to LogCheckpointEnd log message

At Thu, 23 Dec 2021 20:35:54 +0530, Bharath Rupireddy <bharath(dot)rupireddyforpostgres(at)gmail(dot)com> wrote in
> Hi,
>
> It is useful (for debugging purposes) if the checkpoint end message
> has the checkpoint LSN and REDO LSN [1]. It gives more context while
> analyzing checkpoint-related issues. The pg_controldata gives the last
> checkpoint LSN and REDO LSN, but having this info alongside the log
> message helps analyze issues that happened previously, connect the
> dots and identify the root cause.
>
> Attaching a small patch herewith. Thoughts?

A big +1 from me. I thought about proposing the same in the past.

> [1]
> 2021-12-23 14:58:54.694 UTC [1965649] LOG: checkpoint starting:
> shutdown immediate
> 2021-12-23 14:58:54.714 UTC [1965649] LOG: checkpoint complete: wrote
> 0 buffers (0.0%); 0 WAL file(s) added, 0 removed, 0 recycled;
> write=0.001 s, sync=0.001 s, total=0.025 s; sync files=0,
> longest=0.000 s, average=0.000 s; distance=0 kB, estimate=0 kB;
> LSN=0/14D0AD0, REDO LSN=0/14D0AD0

I thougt about something like the following, but your proposal may be
clearer.

> WAL range=[0/14D0340, 0/14D0AD0]

regards.

--
Kyotaro Horiguchi
NTT Open Source Software Center