Horton

Re: [PATCH] pg_stat_activity: make slow/hanging authentication more visible

Jacob Champion <jacob.champion@enterprisedb.com>

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From: Jacob Champion <jacob.champion@enterprisedb.com>
To: Andres Freund <andres@anarazel.de>
Cc: Michael Paquier <michael@paquier.xyz>, Robert Haas <robertmhaas@gmail.com>, Noah Misch <noah@leadboat.com>, Andrew Dunstan <andrew@dunslane.net>, PostgreSQL Hackers <pgsql-hackers@postgresql.org>, Euler Taveira <euler.taveira@enterprisedb.com>, Daniel Gustafsson <daniel@yesql.se>
Date: 2025-03-12T22:16:02Z
Lists: pgsql-hackers 
On Fri, Mar 7, 2025 at 10:28 AM Jacob Champion
<jacob.champion@enterprisedb.com> wrote:
> > I think some of the wrapped calls into library code might actually call back
> > into our code (to receive/send data), and our code then will use wait events
> > around lower level operations done as part of that.
>
> That would be a problem, agreed, but I didn't think I'd wrapped any
> callback APIs. (Admittedly I have little experience with the SSPI
> stuff.) But looking at the wrapped calls in the patch... which are you
> suspicious of?

I missed PAM_CONV, sorry. I'm worried about the sendAuthRequest()
being done there; it doesn't seem safe to potentially ereport(ERROR)
and longjmp through a PAM call stack? But I'll switch those over to
something safe or else drop that part of the patch.

Thanks,
--Jacob

Commits

  1. Fix race condition in TAP test 007_pre_auth

  2. Split pgstat_bestart() into three different routines

  3. backport: Extend background_psql() to be able to start asynchronously

  4. backport: Improve handling of empty query results in BackgroundPsql

  5. Improve handling of empty query results in BackgroundPsql::query()

  6. Extend Cluster.pm's background_psql() to be able to start asynchronously

  7. dblink: Replace WAIT_EVENT_EXTENSION with custom wait events