Re: LISTEN/NOTIFY ultra slow speed - Mailing list pgsql-general

From Арсен Арутюнян
Subject Re: LISTEN/NOTIFY ultra slow speed
Date
Msg-id 1647329663.754713354@f111.i.mail.ru
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In response to LISTEN/NOTIFY ultra slow speed  (Арсен Арутюнян <arutar@bk.ru>)
Responses Re[2]: LISTEN/NOTIFY ultra slow speed
List pgsql-general
 
1)
select version();
                          version
------------------------------------------------------------
 PostgreSQL 10.6, compiled by Visual C++ build 1800, 64-bit
 
2) $PGDATA/pg_notify/
Sometimes this folder is empty, sometimes it contains the file I have attached. The file is always less than 200kb
 
 
--
Arsen Arutyunyan
 
 
Понедельник, 14 марта 2022, 15:53 +03:00 от Арсен Арутюнян <arutar@bk.ru>:
 
    Hello! I'm having trouble with LISTEN/NOTIFY speed. Now I have about 100-200 (few?) clients who are actively messaging. But recently I started to notice a drop in speed. Changing the log_min_duration_statement parameter did not show slow queries in the log.
    As it turned out, the pg_notify(text ,text) function
          or the
          NOTIFY text, 'text' queries takes an extremely long time (0.7-1.5sec),
    but the select pg_notification_queue_usage() query always returns 0.
Please tell me what's the matter, where did I make a mistake? 
What needs to be done to increase the speed of adding to the message queue?
 
--
Arsen Arutyunyan
|What PG version is this exactly?  What is in $PGDATA/pg_notify/ ?
|            regards, tom lane
 
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