2017-03-09 18:28 GMT+01:00 Robert Haas <robertmh...@gmail.com>: > 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.
Dtrace from solaris: http://pastebin.com/u03uVKbr
