52 GB
On Fri, Apr 14, 2017 at 1:50 PM, Moreno Andreo <moreno.andreo@evolu-s.it> wrote:
Sorry,
my mistake (I'm a bit nervous...)
that's not work_mem, but shared_buffers
Thanks
Il 14/04/2017 19:33, Melvin Davidson ha scritto:
On Fri, Apr 14, 2017 at 1:12 PM, Moreno Andreo <moreno.andreo@evolu-s.it> wrote:
Hi all,
About 2 hours and half ago, suddenly (and on the late afternoon of the Easter Friday), customers reported failing connections to our server, or even very slow.
After a bit of checking (that also involved server reboot) I noticed (using top) that every process regarding postgres is using exactly the amout I configured as work_mem (3 GB). And AFAIK it's not good.
30085 postgres 20 0 3370048 156656 153876 S 6.7 0.3 0:00.20 postgres
29833 postgres 20 0 3370000 65260 62416 S 1.7 0.1 0:00.17 postgres
29632 postgres 20 0 3372468 11712 6028 S 0.7 0.0 0:00.60 postgres
What can be happened?
Nothing has been touched....
postgresql 9.5.6 on debian 8 just apt-get upgrade'd
Any help would be appreciated.
Moreno.
>using exactly the amout I configured as work_mem (3 GB).
You are right, that is bad, but that is your own fault. 3GB of work_mem is very bad, Try lowing in to something more reasonable, like 20GB.
https://www.postgresql.org/docs/9.5/static/runtime- config-resource.html#RUNTIME- CONFIG-RESOURCE-MEMORY
"several running sessions could be doing such operations concurrently. Therefore, the total memory used could be many times the value of work_mem; it is necessary to keep this fact in mind when choosing the value."
--
Melvin Davidson
I reserve the right to fantasize. Whether or not you
wish to share my fantasy is entirely up to you.
A. Total SYSTEM MEMORYPerhaps if you provided us with the following information it would be more useful,Moreno,we are working with minimal information here.
3 GB (was 13 GB)B. shared_memory
defaultC. work_memory
1000D. max_connections
About 350 connectionsE. How many users were connected when the problem occurred?
--
Melvin Davidson
I reserve the right to fantasize. Whether or not you
wish to share my fantasy is entirely up to you.