Horton

Re: please update ps display for recovery checkpoint

Robert Haas <robertmhaas@gmail.com>

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From: Robert Haas <robertmhaas@gmail.com>
To: "Bossart, Nathan" <bossartn@amazon.com>
Cc: Justin Pryzby <pryzby@telsasoft.com>, Michael Paquier <michael@paquier.xyz>, Fujii Masao <masao.fujii@oss.nttdata.com>, "k.jamison@fujitsu.com" <k.jamison@fujitsu.com>, Thomas Munro <thomas.munro@gmail.com>, "pgsql-hackers@postgresql.org" <pgsql-hackers@postgresql.org>, Nitin Jadhav <nitinjadhavpostgres@gmail.com>
Date: 2021-06-07T17:28:06Z
Lists: pgsql-hackers 
On Mon, Jun 7, 2021 at 12:02 PM Bossart, Nathan <bossartn@amazon.com> wrote:
> On 6/6/21, 7:14 PM, "Justin Pryzby" <pryzby@telsasoft.com> wrote:
> > Now, I wonder whether the startup process should also include some detail about
> > "syncing data dir".  It's possible to strace the process to see what it's
> > doing, but most DBA would probably not know that, and it's helpful to know the
> > status of recovery and what part of recovery is slow: sync, replay, or
> > checkpoint.  commit df9274adf improved the situation between replay and
> > ckpoint, but it's still not clear what "postgres: startup" means before replay
> > starts.
>
> I've seen a few functions cause lengthy startups, including
> SyncDataDirectory() (for which I was grateful to see 61752afb),
> StartupReorderBuffer(), and RemovePgTempFiles().  I like the idea of
> adding additional information in the ps title, but I also think it is
> worth exploring additional ways to improve on these O(n) startup
> tasks.

See also the nearby thread entitled "when the startup process doesn't"
which touches on this same issue.

-- 
Robert Haas
EDB: http://www.enterprisedb.com

Commits

  1. Provide recovery_init_sync_method=syncfs.

  2. Add some checkpoint/restartpoint status to ps display