Horton
Menu

Re: WIP: WAL prefetch (another approach)

Greg Stark <stark@mit.edu>

View thread
From: Greg Stark <stark@mit.edu>
To: Tom Lane <tgl@sss.pgh.pa.us>
Cc: Thomas Munro <thomas.munro@gmail.com>, Tomas Vondra <tomas.vondra@enterprisedb.com>, Daniel Gustafsson <daniel@yesql.se>, Stephen Frost <sfrost@snowman.net>, Alvaro Herrera <alvherre@2ndquadrant.com>, Andres Freund <andres@anarazel.de>, David Steele <david@pgmasters.net>, Dmitry Dolgov <9erthalion6@gmail.com>, Jakub Wartak <Jakub.Wartak@tomtom.com>, Tomas Vondra <tomas.vondra@2ndquadrant.com>, pgsql-hackers <pgsql-hackers@postgresql.org>
Date: 2021-12-17T02:36:37Z
Lists: pgsql-hackers 
On Fri, 26 Nov 2021 at 21:47, Tom Lane <tgl@sss.pgh.pa.us> wrote:
>
> Yeah ... on the one hand, that machine has shown signs of
> hard-to-reproduce flakiness, so it's easy to write off the failures
> I saw as hardware issues.  On the other hand, the flakiness I've
> seen has otherwise manifested as kernel crashes, which is nothing
> like the consistent test failures I was seeing with the patch.

Hm. I asked around and found a machine I can use that can run PPC
binaries, but it's actually, well, confusing. I think this is an x86
machine running Leopard which uses JIT to transparently run PPC
binaries. I'm not sure this is really a good test.

But if you're interested and can explain the tests to run I can try to
get the tests running on this machine:

IBUILD:~ gsstark$ uname -a
Darwin IBUILD.MIT.EDU 9.8.0 Darwin Kernel Version 9.8.0: Wed Jul 15
16:55:01 PDT 2009; root:xnu-1228.15.4~1/RELEASE_I386 i386

IBUILD:~ gsstark$ sw_vers
ProductName: Mac OS X
ProductVersion: 10.5.8
BuildVersion: 9L31a

Commits

Same data as JSON: GET /api/v1/messages/:b64id/commits the thread's linked commits as JSON, with link sources. API reference →

  1. Fix recovery_prefetch docs.

  2. Prefetch data referenced by the WAL, take II.

  3. Add circular WAL decoding buffer, take II.

  4. Fix generation of ./INSTALL for the distribution tarball

  5. Revert recovery prefetching feature.

  6. Sync guc.c and postgresql.conf.sample with the SGML docs.

  7. Add information of total data processed to replication slot stats.

  8. Doc: Review for "Optionally prefetch referenced data in recovery."

  9. Add circular WAL decoding buffer.

  10. Optionally prefetch referenced data in recovery.

  11. Remove read_page callback from XLogReader.

  12. Provide ReadRecentBuffer() to re-pin buffers by ID.

  13. Provide recovery_init_sync_method=syncfs.

  14. Mark factorial operator, and postfix operators in general, as deprecated.

  15. Rationalize GetWalRcv{Write,Flush}RecPtr().

  16. Support PrefetchBuffer() in recovery.

  17. Prevent hard failures of standbys caused by recycled WAL segments