On 31 Srpen 2011, 1:07, Dan Scott wrote: > On Tue, Aug 30, 2011 at 13:52, Daniel Verite <daniel@xxxxxxxxxxxxxxxx> > wrote: >> Dan Scott wrote: >> >>> the insert process is unable to insert new rows into the database >> >> You should probably provide the error message on insert or otherwise >> describe >> how it's not working. Normally reading does not unintentionally prevent >> writing in a concurrent session. > > I've investigated a little further and it seems that they don't really > 'fail'. Just start taking significantly longer to insert, and the > messages start backing up and eventually stop being sent because What messages are you talking about? > they're not being acknowledged. I can see a few "WARNING: pgstat wait > timeout" messages around the time that this is happening in the > syslog. The pgstat messages are a typical symptom of I/O bottleneck - it just means you'ro doing a lot of writes, more than the drives can take. Enable checkpoint logging (log_checkpoints=on) and watch the system stats (e.g. using 'iostat -x' or vmstat), my bet is this is a checkpoint or pdflush issue. Anyway we need more info about your system - Pg version, amount of RAM, shared buffers, checkpoint settings (segments, completion) and page cache config (/proc/sys/vm/). A few lines of vmstat/iostat output would help too. Tomas -- Sent via pgsql-general mailing list (pgsql-general@xxxxxxxxxxxxxx) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-general
