Re: postgresql memory problem

On Mon, 2022-02-21 at 10:56 +0300, Kenny Bachman wrote:
> Firstly, I want to thank you all for the amazing help.
> I need your guidance with PostgreSQL. So, I have a 3-nodes patroni cluster running PostgreSQL 12.9 version. I got some errors related to a memory issue.
>
> ERROR:  could not resize shared memory segment "/PostgreSQL.346141036" to 16776236 bytes: No space left on device
>
> FATAL:  out of memory
> DETAIL:  Failed on request of size 128 in-memory context "CacheMemoryContext"
>
> My PostgreSQL parameters related to memory;
> work_mem : 128MB
> shared_buffer: 16GB
> effective_cache_size: 200GB
> maintenance_work_mem: 2GB
>
> My server profile:
> free -g
>                     total        used        free      shared  buff/cache   available
> Mem:            377          28          22           0         326         347
> Swap:           127           0         127
>
> df
> tmpfs                        189G  2.0M  189G   1% /dev/shm
>
> What do you think about this? Can you advise some hints?

There should be a memory dump in the PostgreSQL log.
Considering the small size of 128, the problem might be somewhere else.

Yours,
Laurenz Albe
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