On Sat, Nov 2, 2013 at 11:54 AM, Евгений Селявка <evg.selyavka@xxxxxxxxx> wrote: > DB size is about 20GB. There is no high write activity on DB. But > periodically in postgresql log i see for example: "select 1" duration is > about 500-1000 ms. > > In this period of time response time from db terribly. This period of time > not bound with high traffic. It is not other app on the server. There is not > specific cron job on server. Have you shown all the modified kernel settings? Don't you use huge pages accidentally? It might be a transparent huge pages defragmentation issue, the symptoms look similar. Another thing that might cause it is network. Try to monitor it at the time of these stalls. -- Kind regards, Sergey Konoplev PostgreSQL Consultant and DBA http://www.linkedin.com/in/grayhemp +1 (415) 867-9984, +7 (901) 903-0499, +7 (988) 888-1979 gray.ru@xxxxxxxxx -- Sent via pgsql-performance mailing list (pgsql-performance@xxxxxxxxxxxxxx) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-performance
