Re: please update ps display for recovery checkpoint

On Mon, Dec 14, 2020 at 12:01:33PM +0900, Michael Paquier wrote:
> On Sat, Dec 12, 2020 at 12:41:25AM +0000, Bossart, Nathan wrote:
> > On 12/11/20, 4:00 PM, "Michael Paquier" <michael@paquier.xyz> wrote:
> >> My counter-proposal is like the attached, with the set/reset part not
> >> reversed this time, and the code indented :p
> > 
> > Haha.  LGTM.
> 
> Thanks.  I have applied this one, then.

To refresh: commit df9274adf adds "checkpoint" info to "ps", which previously
continued to say "recovering NNNNN" even after finishing WAL replay, and
throughout the checkpoint.

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.

There's some interaction between Thomas' commit 61752afb2 and
recovery_init_sync_method - if we include a startup message, it should
distinguish between "syncing data dirs (fsync)" and (syncfs).

Putting this into fd.c seems to assume that we can clobber "ps", which is fine
when called by StartupXLOG(), but it's a public interface, so I'm not sure if
it's okay to assume that's the only caller.  Maybe it should check if
MyAuxProcType == B_STARTUP.

-- 
Justin