> On Wed, Nov 16, 2011 at 4:07 AM, Maksym Boguk <maxim.bo...@gmail.com> wrote: >> Again I not sure it is actual bug or something else go wrong with my >> database. >> >> One of my databases just started produce 256 wal segments in 5 minutes >> instead of 100-200 wal segments per hour (averages). >> >> In the same time write and read activity on DB stay same (according to the >> pg_stat_database data and historical graphs). >> No anti-wraparound vacuum and such things going on. >> Situation staying same during last few days. >> >> >> I found some other anomalies: >> 1)5 minutes after >> SELECT pg_stat_reset_shared('bgwriter'); >> >> mirtesen=# SELECT * from pg_stat_bgwriter ; >> checkpoints_timed | checkpoints_req | buffers_checkpoint | buffers_clean | >> maxwritten_clean | buffers_backend | buffers_alloc >> -------------------+-----------------+--------------------+---------------+- >> -----------------+-----------------+--------------- >> 0 | 2 | 171675 | 804 | >> 0 | 1010429 | 1131106 >> (1 row) >> >> eg almost any new buffer allocated by backend leading to backend write out >> dirty page (and that situation do not change overtime). > > This sure sounds like a ring buffer is being used, suggesting VACUUM > or COPY IN activity. > > What does pg_stat_activity say? > > -- > Robert Haas > EnterpriseDB: http://www.enterprisedb.com > The Enterprise PostgreSQL Company >
I very sorry, it was a false alert. Monitoring was based on sum() over pg_stat_all_tables. But problem was bugged cron script which were every minute looping over create table something_tmp as query (like 20M entries); instant after drop table something_tmp; As a result of that instant drop - an insert volumes were missed by monitoring. PS: xlogdump really great tool and it was good help in locating and fixing problem. -- Maxim Boguk Senior Postgresql DBA. -- Sent via pgsql-bugs mailing list (pgsql-bugs@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-bugs