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I have setup replication: master - slave. Slave server works as hot-standby, which means we can run read-only sql queries. How actually can I see that slave server is serving read-only queries?

2 Answers2

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You can use pg_is_in_recovery() which returns True if recovery is still in progress(so the server is running in standby mode). Check the System Administration Functions for further informations.

=# SELECT pg_is_in_recovery();
 pg_is_in_recovery
───────────────────
 f
(1 row)
wsn
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    Well, actually I want to know does standby server executes sql queries. For example, on master I can run `SELECT datname, query FROM pg_stat_activity ;` and see what live queries are there. On slave/standby I can only see current query (from pg_stat_activity) –  Feb 23 '15 at 22:18
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    If I execute a read-only query on the master server, is it automatically dispatched to the slave server? – Darion Badlydone Jun 26 '18 at 07:44
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    @DarionBadlydone No, you need to route your read-only query to slave server, by configuring your application or by using proxy software. – wsn Jul 22 '18 at 09:02
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You can see simply with linux top command with pressing c. For example it is a process from our standby site top command list

postgres: pgUserNameSeen pgDatabaseName 10.10.10.10 (56608) idle

if you do not see anything like that, your standby does not server for read-only queries.

ridonekorkmaz
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