Hi Ilya!
> Actually, thise two things are tightly bound and there is no chance to avoid vacuum, you can only postpone it, this kind of work eventually supposed to be done.
I understand that autovacuum has to be done, but not right after previous autovacuum? And then again and again.
And after cancelling that first autovacuum I started another one by hand; from there no autovacuum was cancelled.
> ionice autovacuum instead of mission critical ckeckpointer or bgwriter
Yeah, that was desperate. I restarted server when I had a chance - to drop my ionice settings back to defaults.
> Which exact values have you in the following settings:
autovacuum_analyze_scale_factor = 0.1
autovacuum_analyze_threshold = 50
autovacuum_freeze_max_age = 200000000
autovacuum_max_workers = 3
autovacuum_naptime = 60
autovacuum_vacuum_cost_delay = 20
autovacuum_vacuum_cost_limit = -1
autovacuum_vacuum_scale_factor = 0.2
autovacuum_vacuum_threshold = 50
log_autovacuum_min_duration = 0
All defaults except last one I believe.
Minwhile I noticed in the night logs:
checkpoints are occurring too frequently (138 seconds apart)
Consider increasing the configuration parameter "checkpoint_segments".
Increased checkpoint_segments to 256 and reloaded config.