Magnus Hagander <magnus@hagander.net> writes:
> On Tue, Apr 20, 2021 at 5:17 PM Jehan-Guillaume de Rorthais
> <jgdr@dalibo.com> wrote:
>> Two another options:
>> 1. if this is limited to local access only, outside of the log entries, the
>> status of the startup could be updated in the controldata file as well. This
>> would allows to watch it without tail-grep'ing logs using eg. pg_controldata.
> I think doing so in controldata would definitely make things
> complicated for no real reason. Plus controldata has a fixed size (and
> has to have), whereas something like this would probably want more
> variation than that makes easy.
Also, given that pg_control is as critical a bit of data as we have,
we really don't want to be writing it more often than we absolutely
have to.
> There could be a "startup.status" file I guess which would basically
> contain the last line of what would otherwise be in the log. But if it
> remains a textfile, I'm not sure what the gain is -- you'll just have
> to have the dba look in more places than one to find it? It's not like
> there's likely to be much other data written to the log during these
> times?
Yeah, once you are talking about dumping stuff in a file, it's not
clear how that's better than progress-messages-in-the-log. People
already have a lot of tooling for looking at the postmaster log.
I think the point of Robert's other proposal is to allow remote
checks of the restart's progress, so local files aren't much of
a substitute anyway.
regards, tom lane