At Thu, 3 Sep 2020 13:16:59 -0400, Stephen Frost <sfr...@snowman.net> wrote in > Greetings, > > * Kyotaro Horiguchi (horikyota....@gmail.com) wrote: > > At Mon, 01 Jun 2020 18:00:01 +0900 (JST), Kyotaro Horiguchi > > <horikyota....@gmail.com> wrote in > > > Rebased on the current HEAD. 36ac359d36 conflicts with this. Tranche > > > > Hmm. This conflicts with 0fd2a79a63. Reabsed on it. > > Thanks for working on this and keeping it updated! > > I've started taking a look and at least right off... > > > >From 4926e50e7635548f86dcd0d36cbf56d168a5d242 Mon Sep 17 00:00:00 2001 > > From: Kyotaro Horiguchi <horikyoga....@gmail.com> > > Date: Mon, 16 Mar 2020 17:15:35 +0900 > > Subject: [PATCH v35 1/7] Use standard crash handler in archiver. > > > > The commit 8e19a82640 changed SIGQUIT handler of almost all processes > > not to run atexit callbacks for safety. Archiver process should behave > > the same way for the same reason. Exit status changes 1 to 2 but that > > doesn't make any behavioral change. > > Shouldn't this: > > a) be back-patched, as the other change was > b) also include a change to have the stats collector (which I realize is > removed later on in this patch set, but we're talking about fixing > existing things..) for the same reason, and because there isn't much > point in trying to write out the stats after we get a SIGQUIT, since > we're just going to blow them away again since we're going to go > through crash recovery..? > > Might be good to have a separate thread to address these changes.
+1 > I've looked through (some of) this thread and through the patches also > and hope to provide a review of the bits that should be targetting v14 > (unlike the above) soon. Thanks. Current the patch is found to lead to write contention heavier than the current stats collector when nearly a thousand backend heavily write to the same table. I need to address that. - Collect stats via sockets (in the same way as the current implement) and write/read to/from shared memory. - Use our own lock-free (maybe) ring-buffer before stats-write enters lock-waiting mode, then new stats collector(!) process consumes the queue. - Some other measures.. Anyway, I'll post a rebased version soon. regards. -- Kyotaro Horiguchi NTT Open Source Software Center
