> Subject: [GENERAL] Running out of memory on vacuum > > Hi all, > > I have a production database that sometimes runs out of memory=at > nightly vacuum. > > The application runs typically with around 40 post=res connections but > there are times when the connections increase because =f some queries > going on. The reason is that the operations are slow, the t=rminals > time out and try to reconnect using new connections. Some time ago=I > started to have problems with too many connections being open so I > lower=d the limit to > 300 connections. It was all good until recently when even w=th 180 > connections I am running out of memory on vacuum... So the connecti=ns > increase to 180 and the system still runs properly for other 2 days > but=then at nightly vacuum runs out of memory. > The fix is to restart postgre= ... If I only close the connections the > problem is still these so I need =o restart postgres. > If I don't restart postgres then the system will run=out of memory on > queries at a point... > Another important thing is that d=ring vacuum at 1am nothing else is > going on that server so all the connect=ons are idle. > > 2013-05-14 06:53:51.449 > CST,"postgres","abrazo",8=41,"[local]",519233dc.2225,3,"VACUUM",2013- > 05-14 > 06:53:48 CST,174/67143,0,=RROR,53200,"out of memory","Failed on request > of size 668141820.",,,,,"vac=um;",,,"psql" > > OS: > > SUSE Linux Enterprise Server 11 (x86_64) VER=ION = 11 PATCHLEVEL = 2 > > Suse compiled postgre version : > =A0 =A0 =A0 version > ----------------------------------------------=------------------------ > --------------------------------------------------=-- > PostgreSQL 9.0.3 on x86_64-suse-linux-gnu, compiled by GCC gcc (SU=E > Linux) 4.3.4 [gcc-4_3-branch revision 152973], 64-bit > > Postgre= configuration parameters: > > max_connections = 300 > shared_buffers =3D 2GB > maintenance_work_mem = 2GB > effective_cache_size = 4GB > wor=_mem = 2MB > wal_buffers = 1MB > > > checkpoint_segments = 16 > au=ovacuum = on > > > wal_level = hot_standby > archive_mode = on > a=chive_command = 'test -f > /cbnDBscripts/tmp/PITR_primarydb_stop_backup ||=rsync --timeout=30 -atz > %p spsnidb1:/data01/wal_files/%f' > archive_time=ut = 60 > > > free > > total =A0 > used free > shared buffer= cached > Mem: > 7880512 7825136 =A0 > 55376 > 0 72376 =A0 4537644 -/+ > buffers/cache: 3215116 4665396 > Swap:=A0 > 2097148 > 0 2097148 > > =etc/sysctl.conf > > kernel.shmmax=2684354560 > kernel.shmall=26843545=0 > vm.swappiness=0 > vm.overcommit_memory=2 > ..... > > Thanks, > ioana
1. You have autovacuum running. Is there specific reason to run "manual" vacuum nightly? 2. Reduce maintenance_work_mem, you may have manual vacuum and autovacuum running at the same time, each requesting 2GB (your current setting). 3. Use connection pooling software (e.g. PgBouncer) and reduce max_connections. Igor Neyman -- Sent via pgsql-general mailing list (pgsql-general@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-general
