Horton

Re: when the startup process doesn't

Alvaro Herrera <alvherre@alvh.no-ip.org>

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From: Alvaro Herrera <alvherre@alvh.no-ip.org>
To: Robert Haas <robertmhaas@gmail.com>
Cc: "pgsql-hackers@postgresql.org" <pgsql-hackers@postgresql.org>
Date: 2021-04-19T23:16:37Z
Lists: pgsql-hackers 
On 2021-Apr-19, Robert Haas wrote:

> Another possible approach would be to accept connections for
> monitoring purposes even during crash recovery. We can't allow access
> to any database at that point, since the system might not be
> consistent, but we could allow something like a replication connection
> (the non-database-associated variant).

Hmm.  We already have pg_isready, which is pretty simplistic -- it tries
to connect to the server and derive a status in a very simplistic way.
Can we perhaps improve on that?  I think your idea of using the
non-database-connected replication mode would let the server return a
tuple with some status information with a new command.  And then
pg_isready could interpret that, or just print it.

-- 
Álvaro Herrera                            39°49'30"S 73°17'W
Subversion to GIT: the shortest path to happiness I've ever heard of
                                                (Alexey Klyukin)

Commits

  1. Un-revert "Disable STARTUP_PROGRESS_TIMEOUT in standby mode."

  2. Revert "Disable STARTUP_PROGRESS_TIMEOUT in standby mode."

  3. Disable STARTUP_PROGRESS_TIMEOUT in standby mode.

  4. Fix race condition in startup progress reporting.

  5. Report progress of startup operations that take a long time.

  6. Add enable_timeout_every() to fire the same timeout repeatedly.