Re: PG 11.8 > PG 12.3 : Unable to allocate section memory

Please specify some other stuff:

1. PG onprem or cloud? If cloud, which one and what instance type.
2. Is it a dedicated PG host?  How many hyper threads and memory do you
have?
3. Does PGBouncer run on another host or on the same host as PG?

JOIGNY Michael @Neteven wrote on 8/12/2020 10:09 AM:
>
> Hi Community,
>
> We have migrated from postgresql 11.8 to 12.3,unfortunately we have
> sometimes the following errors in the logs, causing postgres process
> to be killed.
>
> 2020-08-12 14:20:29.043 CEST [134644]: [71-1]
> user=xx,db=xx,app=[unknown],client=localhost FATAL:  out of memory
> 2020-08-12 14:20:29.049 CEST [30022]: [6126-1]
> user=xx,db=xx,app=[unknown],client=localhost FATAL:  fatal llvm error:
> Unable to allocate section memory!
> 2020-08-12 14:20:29.197 CEST [78792]: [1-1] user=,db=,app=,client=
> FATAL:  terminating connection due to administrator command
> 2020-08-12 14:20:29.197 CEST [78791]: [1-1] user=,db=,app=,client=
> FATAL:  terminating connection due to administrator command
> 2020-08-12 14:20:29.197 CEST [78793]: [1-1] user=,db=,app=,client=
> FATAL:  terminating connection due to administrator command
> 2020-08-12 14:20:29.197 CEST [78790]: [1-1] user=,db=,app=,client=
> FATAL:  terminating connection due to administrator command
> 2020-08-12 14:21:02.621 CEST [86289]: [2-1]
> user=postgres,db=template1,app=[unknown],client=[local] FATAL: out of
> memory
> 2020-08-12 14:21:04.632 CEST [29597]: [26704-1]
> user=xx,db=xx,app=[unknown],client=localhost FATAL:  fatal llvm error:
> Unable to allocate section memory!
>
> Here are our settings :
>
> _PG :_
>
> max_connections = 3600
>
> shared_buffers = 32GB
> temp_buffers = 16MB
> work_mem = 96MB
> maintenance_work_mem = 8GB
> max_stack_depth = 6MB
> dynamic_shared_memory_type = posix
>
> We use postgresql with pgbouncer as a pooler.
>
>
> _PGbouncer :
> _
>
> pooler mode : session
> max_client_conn = 6000
> default_pool_size = 3000
>
> We have ~ 2000 connections at the same time with ~ 20/30 are active.
>
> Note that we had the same configuration under PG11 without any problem.
>
> Do you have an idea ?
>
> Regards.
>