Reply-To: mjoigny@neteven.com
From: "JOIGNY Michael @Neteven" <mjoigny@neteven.com>
To: pgsql-admin@postgresql.org
Subject: PG 11.8 > PG 12.3 : Unable to allocate section memory
Message-ID: <64eae88b-8ac5-366c-b6a2-e7b59b3d191b@neteven.com>
Date: Wed, 12 Aug 2020 16:09:08 +0200
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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.


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  <body>
    <p>Hi Community,</p>
    We have migrated from postgresql 11.8 to 12.3,<span lang="en">
      unfortunately </span>we have sometimes the following errors in
    the logs, causing postgres process to be killed. <br>
    <br>
    <font size="-1">2020-08-12 14:20:29.043 CEST [134644]: [71-1]
      user=xx,db=xx,app=[unknown],client=localhost FATAL:  out of memory<br>
      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!<br>
      2020-08-12 14:20:29.197 CEST [78792]: [1-1] user=,db=,app=,client=
      FATAL:  terminating connection due to administrator command<br>
      2020-08-12 14:20:29.197 CEST [78791]: [1-1] user=,db=,app=,client=
      FATAL:  terminating connection due to administrator command<br>
      2020-08-12 14:20:29.197 CEST [78793]: [1-1] user=,db=,app=,client=
      FATAL:  terminating connection due to administrator command<br>
      2020-08-12 14:20:29.197 CEST [78790]: [1-1] user=,db=,app=,client=
      FATAL:  terminating connection due to administrator command<br>
      2020-08-12 14:21:02.621 CEST [86289]: [2-1]
      user=postgres,db=template1,app=[unknown],client=[local] FATAL: 
      out of memory<br>
      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!</font><br>
    <p>Here are our settings : <br>
    </p>
    <p><u>PG :</u><br>
    </p>
    <p><font size="-1">max_connections = 3600     <br>
      </font></p>
    <p>
    </p>
    <font size="-1">shared_buffers = 32GB            <br>
      temp_buffers = 16MB                 <br>
      work_mem = 96MB                     <br>
      maintenance_work_mem = 8GB            <br>
      max_stack_depth = 6MB                   <br>
      dynamic_shared_memory_type = posix  </font><br>
    <p>We use postgresql with pgbouncer as a pooler.</p>
    <font size="-1"> </font><br>
    <p><u>PGbouncer : <br>
      </u></p>
    <p><font size="-1">pooler mode : session<br>
        max_client_conn = 6000<br>
        default_pool_size = 3000</font></p>
    <span lang="en">We have ~ 2000 connections at the same time with ~
      20/30 are active.
      <br>
      <br>
      Note that we had the same configuration under PG11 without any
      problem.</span><br>
    <p>Do you have an idea ?</p>
    <p>Regards.<br>
    </p>
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