I am trying to configure replication in Postgres, and running into an issue where the server is ignoring the setting for wal_level in the configuration file.
I have set in the config file:
wal_level = hot_standby max_wal_senders = 5
However when I went to start Postgres I ran into the error:
WAL streaming (max_wal_senders > 0) requires wal_level "archive", "hot_standby", or "logical"
If I set max_wal_senders = 0, the server starts fine, but running "show all" in psql shows that wal_level = minimal.
-bash-4.2$ grep wal_level postgresql.conf wal_level = hot_standby # minimal, archive, hot_standby, or logical -bash-4.2$ psql -c 'show "wal_level";' wal_level ----------- minimal
Any idea why it would be ignoring the configuration value?
Nothing of note in the Postgres error log:
Oct 13 11:03:53 postgres[12324]: [3-1] LOG: database system was shut down at 2016-10-13 10:55:35 UTC Oct 13 11:03:53 postgres[12324]: [4-1] LOG: MultiXact member wraparound protections are now enabled Oct 13 11:03:53 postgres[12328]: [3-1] LOG: autovacuum launcher started Oct 13 11:03:53 postgres[12321]: [3-1] LOG: database system is ready to accept connections
Just the one wal_level config line and archive_mode is enabled and configured to rsync archive files to the slave. I've uploaded the config here: http://pastebin.com/Vi3vByc1
I've checked and it's definitely loading the correct config file.
-bash-4.2$ psql -c 'show config_file;'
config_file
--------------------------------------
/data/pgsql/9.5/data/postgresql.conf
(1 row)
-bash-4.2$ grep wal_level /data/pgsql/9.5/data/postgresql.conf
wal_level = hot_standby # minimal, archive, hot_standby, or logical
Best Answer
Take a look at the postgresql.auto.conf file - it's populated if you changed it using
alter system. Also, make sure to restart the instance and not just reload it as this kind of change requires restart.