Re: Streaming replica hangs periodically for ~ 1 second - how to diagnose/debug

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(dot)klaver(at)aklaver(dot)com