"Anand Kumar, Karthik" <Karthik.AnandKumar@xxxxxxxxxxxxxx> wrote: > We finally made some headway on this - we noticed messages like > the below > in /var/log/messages whenever the issue happened: > > Mar 26 07:39:58 site-db01b kernel: postmaster: page allocation failure. > Anyone have any idea why memory was so fragmented, and what > causes memory to be defragged? Is it something postgres does? Are > there any kernel specific settings that control it? While I agree with other replies that you would benefit from transaction-based connection pooling, there may be another issue at play here. I can't be sure from evidence so far, but this might be related to something I've been looking at related to NUMA memory and how the OS buffers and PostgreSQL shared_buffers interact with it. Most of the available benefit can be realized without any change to the PostgreSQL code by using the cpuset features of the OS. If you want to investigate this, the first thing would be to get a look at the shape of things. Please post the output of this: numactl --hardware The above just reports on the hardware -- it doesn't change anything. -- Kevin Grittner EDB: http://www.enterprisedb.com The Enterprise PostgreSQL Company -- Sent via pgsql-general mailing list (pgsql-general@xxxxxxxxxxxxxx) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-general
