Thanks Laurenz, will try these flags. Regards, Subhrajyoti
On Fri, Oct 1, 2021 at 5:19 PM Laurenz Albe <laurenz.a...@cybertec.at> wrote: > On Fri, 2021-10-01 at 14:22 +0530, Subhrajyoti Senapati wrote: > > Was running a few sysbench tests in Postgres12. > > Sysbench Test Config > > oltp-readwrite-custom > > Threads - 500 > > Machine: 16 core 64G > > > > In PG server: > > shared_buffers: 16GB > > maintenance_work_memory: 16GB > > checkpoint_timeout: 1h > > max_wal_size: 10GB > > wal_sync_method: 'open_sync' > > effective_cache_size: 32GB > > wal_buffers: -1 > > wal_compression: on > > > > Got some qps dips. > > > > Changed fsync and full_page_rewrite to 'off'. > > Which helped in avoiding these many long dips in performance: > > > > But fsync ensures DBMS consistency. So, instead of that can I change a > few other configurations to avoid these inconsistent performance dips ? > > Try playing with "bgwriter_flush_after", "checkpoint_flush_after" and > "wal_writer_flush_after" > and see if that influences the behavior. > > Yours, > Laurenz Albe > -- > Cybertec | https://www.cybertec-postgresql.com > >
