Le mercredi 09 janvier 2008, Jeff Davis a écrit : > On Wed, 2008-01-09 at 22:57 +0100, Hervé Piedvache wrote: > > Hi, > > > > I have a big trouble with a PostgreSQL server ... regulary since I have > > added 8 Gb of memory, on a server having already 8Gb of memory, I have > > troubles. Nothing else have changed ... I'm on a Dell server, and all the > > memory diagnostics from Dell seems to be good ... > > When I have a lot of connexions (persistante connexions from 6 web > > apache/php serveurs using PDO, about 110 process on each web servers) on > > the server, or long request, it's difficult for me to know when it's > > appening, the kernel seems to kill my postgresql process then the server > > become completly instable, and most of the time need a reboot ... > > > > I'm on Linux kernel 2.6.15 with a version 8.1.10 of PostgreSQL. > > My database is a size of 56G > > RAM = 16 Gb > > [snip] > > > Jan 9 20:30:47 db2 kernel: oom-killer: gfp_mask=0x84d0, order=0 > > It looks like the Out Of Memory Killer was invoked, and you need to find > out why it was invoked. > > I posted to LKML here: > > http://kerneltrap.org/mailarchive/linux-kernel/2007/2/12/54202 > > because linux has a behavior -- which in my opinion is a bug -- that > causes the OOM killer to almost always kill PostgreSQL first, regardless > of whether it was truly the offending process or not. > > So, find out which process truly caused the memory pressure that lead to > the OOM being invoked, and fix that problem. How can I process to find this ? It's a production server for a web service, and I have no idea how to find wich process was the cause of this ... !? > You may also consider some other linux configuration options that make > invocation of OOM killer less likely. On this server there is only Postgresql, slony, and sshd running the rest is only Linux basic process (cron, atd, getty etc.) regards, -- Hervé Piedvache ---------------------------(end of broadcast)--------------------------- TIP 3: Have you checked our extensive FAQ? http://www.postgresql.org/docs/faq
