I'm running 9.3.5 on a virtual machine with 5 cores and 24 GB of memory. Disk is on a SAN. I have a task that runs weekly that processes possibly as many as 120 months worth of data, one month at a time. Since moving to 9.3.5 (from 8.2!!) the average time for a month has been 3 minutes or less. However, when this job ran this Tuesday, it ran fine for a number of months, but then started slowing down dramatically, 300 minutes for one month and then 167 minutes for the next. I stopped and restarted postgresql, the next block also ran really slow (157 minutes.) I then rebooted the server and the remaining blocks ran at the usual fast speed again, so restarting postgresql didn't fix the problem but rebooting the server did. Looking at the logs, I see queries with a function call that would normally take no more than 100-200 milliseconds, usually far less, that were taking 100 seconds or longer. This function gets called thousands of times for each month, so that appears to be one source of the slowdown. I don't suspect a memory leak in the calling program (in php), because since moving to this server in December this weekly task has run several times over the same range of months, making pretty much the same function calls each time. I also ran the entire range several times during testing. One change made to the server since the previous week's run was that I moved up to the latest Centos kernel (Linux version 3.10.0-123.13.2.el7.x86_64). As far as I can tell, the other virtual servers weren't being slowed down, so I don't suspect problems with the virtual server or the SAN. If this happens again, what sorts of settings in postgresq.conf or other tools should I be using to try to track down what's causing this? -- Mike Nolan -- Sent via pgsql-general mailing list (pgsql-general@xxxxxxxxxxxxxx) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-general
