Horton

Re: FW: query pg_stat_ssl hang 100%cpu

Thomas Munro <thomas.munro@gmail.com>

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From: Thomas Munro <thomas.munro@gmail.com>
To: "James Pang (chaolpan)" <chaolpan@cisco.com>
Cc: Michael Paquier <michael@paquier.xyz>, PostgreSQL mailing lists <pgsql-bugs@lists.postgresql.org>
Date: 2023-09-07T23:45:51Z
Lists: pgsql-bugs, pgsql-performance

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On Thu, Sep 7, 2023 at 10:59 PM Thomas Munro <thomas.munro@gmail.com> wrote:
> On Thu, Sep 7, 2023 at 10:39 PM James Pang (chaolpan)
> <chaolpan@cisco.com> wrote:
> > (gdb) p RecordCacheArray
> > $1 = (TupleDesc *) 0x7f5fac365d90
> > (gdb) p RecordIdentifierArray
> > $2 = (uint64 *) 0x0
>
> Hah, yeah that's it, and you've been extremely unlucky to hit it.
> ensure_record_cache_typmod_slot_exists() should be more careful about
> cleaning up on allocation failure, to avoid this state.

I think the lazy fix would be to re-order those allocations.  A
marginally more elegant fix would be to merge the arrays, as in the
attached.  Thoughts?

Commits

  1. Fix exception safety bug in typcache.c.