Horton

Re: Replication slot stats misgivings

Amit Kapila <amit.kapila16@gmail.com>

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From: Amit Kapila <amit.kapila16@gmail.com>
To: vignesh C <vignesh21@gmail.com>
Cc: Masahiko Sawada <sawada.mshk@gmail.com>, Andres Freund <andres@anarazel.de>, pgsql-hackers <pgsql-hackers@postgresql.org>, Kyotaro HORIGUCHI <horiguchi.kyotaro@lab.ntt.co.jp>
Date: 2021-04-28T03:29:45Z
Lists: pgsql-hackers 
On Tue, Apr 27, 2021 at 11:02 AM vignesh C <vignesh21@gmail.com> wrote:
>
> On Tue, Apr 27, 2021 at 9:48 AM vignesh C <vignesh21@gmail.com> wrote:
> >
>
> Attached patch has the changes to update statistics during
> spill/stream which prevents the statistics from being lost during
> interrupt.
>

 void
-UpdateDecodingStats(LogicalDecodingContext *ctx)
+UpdateDecodingStats(ReorderBuffer *rb)

I don't think you need to change this interface because
reorderbuffer->private_data points to LogicalDecodingContext. See
StartupDecodingContext. Other than that there is a comment in the code
"Update the decoding stats at transaction prepare/commit/abort...".
This patch should extend that comment by saying something like
"Additionally we send the stats when we spill or stream the changes to
avoid losing them in case the decoding is interrupted."


-- 
With Regards,
Amit Kapila.

Commits

  1. Doc: Update logical decoding stats information.

  2. Fix tests for replication slots stats.

  3. Update replication statistics after every stream/spill.

  4. Fix the computation of slot stats for 'total_bytes'.

  5. Another try to fix the test case added by commit f5fc2f5b23.

  6. Use HTAB for replication slot statistics.

  7. Fix test case added by commit f5fc2f5b23.

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

  9. Use NameData datatype for slotname in stats.