Service outage: each postgres process use the exact amount of the configured work_mem

Moreno Andreo <moreno.andreo@xxxxxxxxxx> · Fri, 14 Apr 2017 19:12:13 +0200



    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.