On Thu, Mar 12, 2009 at 1:38 PM, Frank Joerdens <frank@xxxxxxxxxxx> wrote: > On Thu, Mar 12, 2009 at 1:45 AM, Tom Lane <tgl@xxxxxxxxxxxxx> wrote: > [...] >> You could try changing _IOLBF >> to _IOFBF near the head of postmaster/syslogger.c and see if that helps. The patched server is now running on live, and we'll be watching it over the weekend with log_duration = off log_min_duration_statement = 1000 log_statement = 'ddl' and then run a full logging test early next week if there are no problems with the above settings. Can you explain again what the extent of multiplexed messages I'll have to expect is? What exactly is the substance of the tradeoff? Occasionally the server will write the same line twice? Don't really follow why ... And the next problem is that now unfortunately the entire comparison is obfuscated and complicated by a release we did on Monday which has had a strange effect: Quite extreme load average spikes occurring frequently that do not seem to impact query speed - not much anyway or if they do then in a random intermittent manner that's not become apparent (yet) - CPU usage is actually marginally down, locks significantly down, and all other relevant metrics basically unchanged like context switches and memory usage profile. Now, it *seems* that the extra load is caused by idle (sic!) backends (*not* idle in transaction even) consuming significant CPU when you look at htop. I don't have a theory as to that right now. We use pgbouncer as a connection pooler. What could make idle backends load the server substantially? Regards, Frank -- Sent via pgsql-performance mailing list (pgsql-performance@xxxxxxxxxxxxxx) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-performance
