On Thu, Aug 12, 2021 at 8:03 AM Peter Smith <smithpb2250@gmail.com> wrote:
>
> That base data is showing there are similar numbers of keepalives sent
> as there are calls made to WalSndWaitForWal. IIUC it means that mostly
> the loop is sending the special keepalives on the *first* iteration,
> but by the time of the *second* iteration the ProcessRepliesIfAny()
> will have some status already received, and so mostly sending another
> keepalive will be deemed unnecessary.
>
> Based on this, our idea was to simply skip sending the
> WalSndKeepalive(false) for the FIRST iteration of the loop only! PSA
> the patch 0002 which does this skip.
>
I think we should also keep in mind that there are cases where it
seems we are not able to send keep-alive at the appropriate frequency.
See the discussion [1]. This is to ensure that we shouldn't
unintentionally hamper some other workloads by fixing the workload
being discussed here.
[1] - https://www.postgresql.org/message-id/20210913.103107.813489310351696839.horikyota.ntt%40gmail.com
--
With Regards,
Amit Kapila.