Hi,
I would like to come back to you about my memory problem on
postgres 12.
We had the same configuration under postgres 11.8, we disabled JIT
(enabled by default under postgres 12) for segfault problems.
To illustrate the change in memory behavior, here is a screenshot
before / after migration :
<memory.png>
Do you have any idea what could change the behavior in this way?
another parameter enabled by default under postgres 12 like JIT?
Regards.
Le 18/09/2020 à 12:03, JOIGNY Michael
@Neteven a écrit :
Hi Community,
I'm asking for your lights because i'm having memory problems
with postgres.
Examples of logs :
FATAL: could not fork new process for connection: Cannot
allocate memory could not fork new process for connection:
Cannot allocate memory
out of memory DETAIL: Failed on request of size 32800 in
memory context "HashBatchContext".
out of memory DETAIL Failed on request of size 288 in memory
context "CacheMemoryContext".
We use postgresql (primary/standby) with pgbouncer as a pooler,
and repmgr as replication manager.
We have ~ 2000 connections at the same time with ~ 20/30 are
active. (we need to set a high number of connexion on postgres,
because our app uses a lot of different users, and each user on
each app server needs multiple and constant connexions).
Here is my configuration :
system :
Debian : 9.13
Memory : 380 Go
Postgres : 12.4-1.pgdg90+1
Pgbouncer : 1.14
kernel.shmmax = 202591600640
kernel.shmall = 49460840
postgres :
dynamic_shared_memory_type = posix # the default is the
first option
max_connections = 2600 # (change requires restart)
work_mem = 96MB # min 64kB
maintenance_work_mem = 8GB # min 1MB
shared_buffers = 64GB # min 128kB
temp_buffers = 32MB # min 800kB
wal_buffers = 16MB # min 32kB, -1 sets based on
shared_buffers
effective_cache_size = 270GB
pgbouncer :
max_client_conn = 6000
default_pool_size = 2590
reserve_pool_size = 5
pool_mode = session
Do you think that our parameters are not correct compared to our
configuration? Do you have an idea ?
Best regards.
Michael.
