Hi, Yes, lock contention reduced with postgresqlv14. Lock acquire reduced 18% to 10% 10.49 %postgres postgres [.] LWLockAcquire 5.09% postgres postgres [.] _bt_compare
Is lock contention can be reduced to 0-3%? On pg-stat-activity shown LwLock as “BufferCounter” and “WalInsert” On Tuesday, October 26, 2021, Andres Freund <and...@anarazel.de> wrote: > Hi, > > On 2021-10-12 13:05:12 +0530, Ashkil Dighin wrote: > > PostgreSQL version: 13.3 > > You could try postgres 14 - that did improve scalability in some areas. > > > > > Perf data for 24vu(TPC-C) > > -------------------------------- > > > > 18.99% postgres postgres [.] LWLockAcquire > > 7.09% postgres postgres [.] _bt_compare > > 8.66% postgres postgres [.] LWLockRelease > > 2.28% postgres postgres [.] GetSnapshotData > > 2.25% postgres postgres [.] hash_search_with_hash_value > > 2.11% postgres postgres [.] XLogInsertRecord > > 1.98% postgres postgres [.] PinBuffer > > To be more useful you'd need to create a profile with 'caller' information > using 'perf record --call-graph dwarf', and then check what the important > callers are. > > > > Postgres.conf used in Baremetal > > ======================== > > shared_buffers = 128GB(1/4 th RAM size) > > effective_cachesize=392 GB(1/3 or 75% of RAM size) > > If your hot data set is actually larger than s_b, I'd recommend trying a > larger s_b. It's plausible that a good chunk of lock contention is from > that. > > Greetings, > > Andres Freund >
