Thank for your configuration. I have tested with this configuration (amended a bit) and it helps a bit. But i have found the root cause is related to the application that using PG. But yet i can learn much to tune the PG in my restricted environment !.
If the problem is checkpoints, try making your background writer more aggressive. This allows more of the pages to be written to disk before the checkpoint starts. I'll show the settings which have eliminated similar problems for us, but your best settings will depend on hardware and are almost certainly going to be different. In particular, we have a battery backed caching RAID controller, which seems to change the dynamics of these sorts of issues quite a bit.
#bgwriter_delay = 200ms # 10-10000ms between rounds bgwriter_lru_percent = 20.0 # 0-100% of LRU buffers scanned/round bgwriter_lru_maxpages = 200 # 0-1000 buffers max written/round bgwriter_all_percent = 10.0 # 0-100% of all buffers scanned/round bgwriter_all_maxpages = 600 # 0-1000 buffers max written/round
We also adjust a couple other WAL-related settings:
wal_buffers = 160kB # min 32kB # (change requires restart) checkpoint_segments = 10 # in logfile segments, min 1, 16MB each
Since you're on 8.0 I think you'll need to specify wal-buffers as a number of 8KB pages.
