On Thu, Mar 9, 2017 at 7:47 AM, Naytro Naytro <nay...@googlemail.com> wrote: > We are having some performance issues after we upgraded to newest > version of PostgreSQL, before it everything was fast and smooth. > > Upgrade was done by pg_upgrade from 9.4 directly do 9.6.1. Now we > upgraded to 9.6.2 with no improvement. > > Some information about our setup: Freebsd, Solaris (SmartOS), simple > master-slave using streaming replication. > > Problem: > Very high system CPU when master is streaming replication data, CPU > goes up to 77%. Only one process is generating this load, it's a > postgresql startup process. When I attached a truss to this process I > saw a lot o read calls with almost the same number of errors (EAGAIN). > read(6,0x7fffffffa0c7,1) ERR#35 'Resource temporarily unavailable' > > Descriptor 6 is a pipe > > Read call try to read one byte over and over, I looked up to source > code and I think this file is responsible for this behavior > src/backend/storage/ipc/latch.c. There was no such file in 9.4.
Our latch implementation did get overhauled pretty thoroughly in 9.6; see primarily commit 98a64d0bd713cb89e61bef6432befc4b7b5da59e. But I can't guess what is going wrong here based on this information. It might help if you can pull some stack backtraces from the startup process. -- Robert Haas EnterpriseDB: http://www.enterprisedb.com The Enterprise PostgreSQL Company -- Sent via pgsql-hackers mailing list (email@example.com) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers