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Date: Wed, 20 Aug 2025 10:45:13 -0700
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Subject: Re: Streaming replica hangs periodically for ~ 1 second - how to
 diagnose/debug
To: depesz@depesz.com
Cc: PostgreSQL General <pgsql-general@lists.postgresql.org>
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From: Adrian Klaver <adrian.klaver@aklaver.com>
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On 8/20/25 09:08, hubert depesz lubaczewski wrote:
> On Wed, Aug 20, 2025 at 08:14:47AM -0700, Adrian Klaver wrote:
>> Hmm.
>>
>>  From initial post:
>>
>> "For ~ 1 second there are no logs going to log (we usually have at 5-20
>> messages logged per second), no connection, nothing. And then we get
>> bunch (30+) messages with the same milisecond time."
>>
>> Are the 30+ messages all coming in on one connection or multiple
>> connections?
> 
> Multiple connections.
> 
>> Also to be clear these are statements that are being run on the replica
>> locally, correct?
> 
> What do you mean locally?

I should have been clearer. Are the queries being run against the 
replica or the primary?

> 
> Application servers are *not* on the same server as the db. So no, they
> are not local.

Where are the application servers relative to the replica server?

How many applications servers are hitting the database?

> 
>> Does the AWS monitoring indicate any issues?
> 
> Nope. All looks "fine".


> 
> Same for our monitoring  - CPU usage, iops, load.
> 
> Best regards,
> 
> depesz
> 


-- 
Adrian Klaver
adrian.klaver@aklaver.com