On Fri, Nov 18, 2011 at 11:26 AM, Kevin Grittner <kevin.gritt...@wicourts.gov> wrote: > Robert Haas <robertmh...@gmail.com> wrote: >> Nate Boley's AMD 6128 box (which has 32 cores) and an HP Integrity >> server (also with 32 cores). > >> [clear improvement with flexlock patch] > > Hmm. We have a 32-core Intel box (4 x X7560 @ 2.27GHz) with 256 GB > RAM. It's about a week from going into production, at which point > it will be extremely hard to schedule such tests, but for a few days > more I've got shots at it. The flexlock patch doesn't appear to be > such a clear win here. > > I started from Robert's tests, but used these settings so that I > could go to higher client counts and better test serializable > transactions. Everything is fully cached. > > max_connections = 200 > max_pred_locks_per_transaction = 256 > shared_buffers = 8GB > maintenance_work_mem = 1GB > checkpoint_segments = 30 > checkpoint_timeout = 15min > checkpoint_completion_target = 0.9 > seq_page_cost = 0.1 > random_page_cost = 0.1 > cpu_tuple_cost = 0.05 > effective_cache_size = 40GB > default_transaction_isolation = '$iso'
I had a dismaying benchmarking experience recently that involved settings very similar to the ones you've got there - in particular, I also had checkpoint_segments set to 30. When I raised it to 300, performance improved dramatically at 8 clients and above. Then again, is this a regular pgbench test or is this SELECT-only? Because the absolute numbers you're posting are vastly higher than anything I've ever seen on a write test. Can you by any chance check top or vmstat during the 32-client test and see what percentage you have of user time/system time/idle time? What OS are you running? -- Robert Haas EnterpriseDB: http://www.enterprisedb.com The Enterprise PostgreSQL Company -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers
