Re: please update ps display for recovery checkpoint

Nathan Bossart <bossartn@amazon.com>

From: "Bossart, Nathan" <bossartn@amazon.com>
To: Justin Pryzby <pryzby@telsasoft.com>, Michael Paquier <michael@paquier.xyz>
Cc: 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: 2021-06-07T16:02:03Z
Lists: pgsql-hackers
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.

Nathan

Commits

  1. Provide recovery_init_sync_method=syncfs.

  2. Add some checkpoint/restartpoint status to ps display