Re: [HACKERS] CLUSTER command progress monitor

Hi Michael!

> Attached file is WIP patch.In my patch, I added "command id" to all APIs
> of
> > progress reporting to isolate commands. Therefore, it doesn't allow to
> > cascade updating system views. And my patch is on WIP so it needs
> clean-up
> > and test.
> > I share it anyway. :)
>
> + if (cmdtype == PROGRESS_COMMAND_INVALID ||
> beentry->st_progress_command == cmdtype)
> + {
> + PGSTAT_BEGIN_WRITE_ACTIVITY(beentry);
> + beentry->st_progress_param[index] = val;
> + PGSTAT_END_WRITE_ACTIVITY(beentry);
> + }
> You basically don't need the progress reports if the command ID is
> invalid, no?
>

Ah, right.
I'll check and fix that today. :)

>
> Another note is that you don't actually fix the problems related to
> the calls of pgstat_progress_end_command() which have been added for
> REINDEX reporting, so a progress report started for CLUSTER can get
> ended earlier than expected, preventing the follow-up progress updates
> to show up.
>
>

Hmm... I fixed the problem. Please confirm the test result repeated below.
CLUSTER is able to get the last phase: performing final clean up by using
the patch.

# Test result
========================================
postgres=# select * from pg_stat_progress_cluster ; \watch 0.001;
11636|13591|postgres|16384|CLUSTER|initializing|0|0|0|0|0|0
11636|13591|postgres|16384|CLUSTER|index scanning heap|16389|251|251|0|0|0
11636|13591|postgres|16384|CLUSTER|index scanning
heap|16389|10000|10000|0|0|0
11636|13591|postgres|16384|CLUSTER|rebuilding
index|16389|10000|10000|0|0|0 <== The last column rebuild_index_count is
increasing!
11636|13591|postgres|16384|CLUSTER|rebuilding index|16389|10000|10000|0|0|1
11636|13591|postgres|16384|CLUSTER|rebuilding index|16389|10000|10000|0|0|2
11636|13591|postgres|16384|CLUSTER|rebuilding index|16389|10000|10000|0|0|3
11636|13591|postgres|16384|CLUSTER|rebuilding index|16389|10000|10000|0|0|4
11636|13591|postgres|16384|CLUSTER|performing final
cleanup|16389|10000|10000|0|0|5 <== The last phase of CLUSTER!
========================================

Thanks,
Tatsuro Yamada