Re: BUG #17914: walsenders taking up all memory - Mailing list pgsql-bugs

From Stan S
Subject Re: BUG #17914: walsenders taking up all memory
Date
Msg-id CAHcftXry2h728CTH4KAqjkNb_RfEQnVNTOoimKo4VwKzMCsOfA@mail.gmail.com
Whole thread Raw
In response to Re: BUG #17914: walsenders taking up all memory  (Masahiko Sawada <sawada.mshk@gmail.com>)
List pgsql-bugs
Hello,

We use Kafka Connect debezium connectors, which translates to streaming = OFF. We can tell that streaming is off by querying: 
select *
from pg_stat_replication_slots;

And seeing that stream_count is 0.

The way we can tell that walsenders are jumping to 30GB and beyond is checking in RDS --> select instance --> Go to Monitoring --> Select OS Process list

Attaching an example screenshot below:
image.png

Thank you for looking into this!

On Wed, May 3, 2023 at 3:30 AM Masahiko Sawada <sawada.mshk@gmail.com> wrote:
Hi,

On Tue, May 2, 2023 at 5:56 AM PG Bug reporting form
<noreply@postgresql.org> wrote:
>
> The following bug has been logged on the website:
>
> Bug reference:      17914
> Logged by:          Stan S
> Email address:      stashukny@gmail.com
> PostgreSQL version: 14.3
> Operating system:   AWS RDS - (Red Hat 7.3.1-12), 64-bit
> Description:
>
> Seeing the same issue as reported here:
> https://www.postgresql.org/message-id/CAMnUB3oYugXCBLSkih%2BqNsWQPciEwos6g_AMbnz_peNoxfHwyw%40mail.gmail.com
>
> In our case, logical_decoding_work_mem is set to 64 MB, yet walsenders can
> each take up 30 GB of memory, crashing our database.

Thank you for reporting this issue. I have two questions:

* Did you use streaming = off/on on the subscriber?
* How did you confirm the walsender used 30GB of memory?

Regards,

--
Masahiko Sawada
Amazon Web Services: https://aws.amazon.com
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