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Date: Tue, 1 Oct 2024 02:09:31 +0900
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Subject: Re: May be BUG. Periodic burst growth of the checkpoint_req counter
 on replica.
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To: "Anton A. Melnikov" <a.melnikov@postgrespro.ru>,
 Alexander Korotkov <aekorotkov@gmail.com>
Cc: Magnus Hagander <magnus@hagander.net>,
 "Anton A. Melnikov" <aamelnikov@inbox.ru>, Andres Freund
 <andres@anarazel.de>, Kyotaro Horiguchi <horikyota.ntt@gmail.com>,
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From: Fujii Masao <masao.fujii@oss.nttdata.com>
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On 2024/09/30 16:00, Anton A. Melnikov wrote:
> 
> On 30.09.2024 06:26, Fujii Masao wrote:
>> Thanks for the review! I've pushed the 0001 patch.
> 
> Thanks a lot!
> 
>>> As for switching in the pg_proc.dat entries the idea was to put them in order
>>> so that the pg_stat_get_checkpointer* functions were grouped together.
>>> I don't know if this is the common and accepted practice. Simply i like it better this way.
>>> Sure, if you think it's unnecessary, let it stay as is with minimal diff.
>>
>> I understand your point, but I didn't made that change to keep the diff minimal,
>> which should make future back-patching easier.
> 
> Agreed. Its quite reasonable. I've not take into account the backporting
> possibility at all. This is of course wrong.
> 
>>> In addition, checkpoints may be skipped due to "checkpoints are occurring
>>> too frequently" error. Not sure, but maybe add this information to
>>> the new description?
>>
>>  From what I can see in the code, that error message doesn’t seem to indicate
>> the checkpoint is being skipped. In fact, checkpoints are still happening
>> actually when that message appears. Am I misunderstanding something?
> 
> No, you are right! This is my oversight. I didn't notice that elevel is just a log
> not a error. Thanks!

Ok, so I pushed 0002.patch. Thanks for the review!

Regards,

-- 
Fujii Masao
Advanced Computing Technology Center
Research and Development Headquarters
NTT DATA CORPORATION