At Wed, 7 Dec 2022 11:28:23 +0530, Sravan Kumar <sravanvcyb...@gmail.com> wrote in > On Tue, Dec 6, 2022 at 5:24 PM Bharath Rupireddy < > bharath.rupireddyforpostg...@gmail.com> wrote: > > > On Tue, Dec 6, 2022 at 4:57 PM Sravan Kumar <sravanvcyb...@gmail.com> > > wrote: > > > > > > Thank you for the feedback. > > > > > > I'll be glad to help with the fix. Here's the patch for review. > > > > Thanks. +1 for fixing this. > >> I would like to quote recent discussions on reducing the useless > >> wakeups or increasing the sleep/hibernation times in various processes > >> to reduce the power savings [1] [2] [3] [4] [5]. With that in context, > >> does the archiver need to wake up every 60 sec at all when its latch > >> gets set (PgArchWakeup()) whenever the server switches to a new WAL > >> file? What happens if we get rid of PGARCH_AUTOWAKE_INTERVAL and rely > >> on its latch being set? If required, we can spread PgArchWakeup() to > >> more places, no? > > > > > I like the idea of not having to wake up intermittently and probably we > should start a discussion about it. > > I see the following comment in PgArchWakeup(). > > /* > * We don't acquire ProcArrayLock here. It's actually fine because > * procLatch isn't ever freed, so we just can potentially set the wrong > * process' (or no process') latch. Even in that case the archiver will > * be relaunched shortly and will start archiving. > */ > > While I do not fully understand the comment, it gives me an impression that > the SetLatch() done here is counting on the timeout to wake up the archiver > in some cases where the latch is wrongly set.
It is telling about the first iteration of archive process, not periodical wakeups. So I think it is doable by considering how to handle incomplete archiving iterations. > The proposed idea is a behaviour change while this thread intends to clean > up some code that's > a result of the mentioned commit. So probably the proposed idea can be > discussed as a separate thread. Agreed. -- Kyotaro Horiguchi NTT Open Source Software Center
