Horton

Re: pg14b1 stuck in lazy_scan_prune/heap_page_prune of pg_statistic

Justin Pryzby <pryzby@telsasoft.com>

View thread View on postgr.es
From: Justin Pryzby <pryzby@telsasoft.com>
To: Peter Geoghegan <pg@bowt.ie>
Cc: PostgreSQL Hackers <pgsql-hackers@lists.postgresql.org>, Matthias van de Meent <boekewurm+postgres@gmail.com>, Masahiko Sawada <sawada.mshk@gmail.com>, Andres Freund <andres@anarazel.de>, Tom Lane <tgl@sss.pgh.pa.us>
Date: 2021-06-06T18:43:11Z
Lists: pgsql-hackers 
On Sun, Jun 06, 2021 at 11:00:38AM -0700, Peter Geoghegan wrote:
> On Sun, Jun 6, 2021 at 9:35 AM Justin Pryzby <pryzby@telsasoft.com> wrote:
> > I'll leave the instance running for a little bit before restarting (or kill-9)
> > in case someone requests more info.
> 
> How about dumping the page image out, and sharing it with the list?
> This procedure should work fine from gdb:

Sorry, but I already killed the process to try to follow Matthias' suggestion.
I have a core file from "gcore" but it looks like it's incomplete and the
address is now "out of bounds"...

#2  0x00000000004fd9bf in lazy_scan_prune (vacrel=vacrel@entry=0x1d1b390, buf=buf@entry=14138, blkno=blkno@entry=75, page=page@entry=0x2aaab2089e00 <Address 0x2aaab2089e00 out of bounds>,

I saved a copy of the datadir, but a manual "vacuum" doesn't trigger the
problem.  So if Matthias' theory is right, it seems like there may be a race
condition.  Maybe that goes without saying.

-- 
Justin

Commits

  1. Deduplicate choice of horizon for a relation procarray.c.

  2. Use correct horizon when vacuuming catalog relations.

  3. Truncate line pointer array during VACUUM.

  4. Remove tupgone special case from vacuumlazy.c.

  5. Refactor lazy_scan_heap() loop.

  6. snapshot scalability: Don't compute global horizons while building snapshots.