Re: Strange problem with autovacuum

What are your checkpoint / wal settings?

Are there any log entries at those times about autovacuums being cancelled? The log will typically give a reason.

--Stephen

From: pgsql-novice-owner(at)postgresql(dot)org [mailto:pgsql-novice-owner(at)postgresql(dot)org] On Behalf Of Efraín Déctor
Sent: Tuesday, November 14, 2017 8:46 AM
To: pgsql-novice(at)postgresql(dot)org
Subject: [NOVICE] Strange problem with autovacuum

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Hello list.

I have a strange problem with one of our servers (PostgreSQl 9.2.8). Every monday the autovacuum workers seems to stop working (the workers decrease in number) this causes that 5 tables that are constantly updated and deleted to be really slow.

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I have this settings on postgresql.conf:

maintenance_work_mem = 7936MB
autovacuum = on
#log_autovacuum_min_duration = -1
autovacuum_max_workers = 12
#autovacuum_naptime = 1min
#autovacuum_vacuum_threshold = 50
#autovacuum_analyze_threshold = 50
#autovacuum_vacuum_scale_factor = 0.2
#autovacuum_analyze_scale_factor = 0.1
#autovacuum_freeze_max_age = 200000000
#autovacuum_vacuum_cost_delay = 20ms
#autovacuum_vacuum_cost_limit = -1

Per table I have this settings:

datosr

autovacuum_enabled=true,
autovacuum_vacuum_threshold=50,
autovacuum_vacuum_scale_factor=0.1,
autovacuum_vacuum_cost_limit=1000

datose

autovacuum_enabled=true,
autovacuum_vacuum_threshold=50,
autovacuum_vacuum_scale_factor=0.1,
autovacuum_vacuum_cost_limit=1000

idig_h

autovacuum_enabled=true,
autovacuum_vacuum_threshold=1000,
autovacuum_vacuum_cost_limit=2000

iodig

autovacuum_enabled=true,
autovacuum_vacuum_threshold=1000,
autovacuum_vacuum_cost_limit=2000

ia
autovacuum_vacuum_threshold=50,
autovacuum_vacuum_scale_factor=.1,
autovacuum_vacuum_cost_limit=1000

I bases those settings by reading this blog entry: https://blog.2ndquadrant.com/autovacuum-tuning-basics/

It seems that I am doing something wrong, could you guys please point me in the right direction?

Thank you very much