Due to that, cancel often seems like it didn't work. SELECT pg_terminate_backend(25263) FROM pg_stat_activity WHERE -- don't kill my own connection! If the running query is not at a point where it will check for interrupts, it will just keep running. The first method we can use is SELECT pg_cancel_backend(pid).It simply cancels the query and keeps the connection untouched. Depending on the query, that might be anything from seconds to hours before it stops. Unlike the previous one, it not only terminates the query but also shuts down the whole database connection. In case it does not work, you can be a bit more aggressive by killing the connection: ActiveRecord :: Base . (Tatsuo Ishii) Fix segfault in pgpool child process in certain case. Two processes work on app_test and app_test2 database. To cancel a currently running query, first retrieve the process ID for the query that you want to cancel. The two tasks above cannot drop/created databases because the main command still holds the connection. Hi Team , We are observing long running process hung in active state on one of our db from last two days Revisiting this, there are places where PostgreSQL backends are doing work … Test: Fix occasional 073.pg_terminate_backend test failure. Terminate tells the backend itself to … The postgres server uses SIGQUIT to tell subordinate server processes to terminate without normal cleanup. To terminate a backend process cleanly, send SIGTERM to that process. You want pg_terminate_backend.. More fundamentally, it seems like you have an application problem or a connection pooler problem, but you haven't described them enough for us to give advice. Regardless of whatever issues you might have, pg_cancel_backend cancels the backend's current query. execute ( "SELECT pg_terminate_backend( #{ pid } )" ) Alternatively, you can go for “turn it off and on again ” approach by killing all the active database connections and restarting the Ruby processes. This signal should not be pg_terminate_backend() or pg_cancel_backend() (those functions return true but the entries in pg_stat_activity remain), and they persist long after the client application has exited - there were some I found on a staging server that were a month old, and were only resolved by The workaround I can see on the build machine is this set of commands (create the dev database too). But an idle backend doesn't have a current query, which is what makes it idle. (Tatsuo Ishii) This issue can be reproduced with the following steps: Shutdown all backends. Examples. You can use the pg_terminate_backend() function to terminate the database session that is blocking your VACUUM. connection . Connect to pgpool with invalid client. I have used pcp_attach_node with pgpool's port number, not pcp's. See also pg_cancel_backend and pg_terminate_backend in Section 9.26.2 for the SQL-callable equivalents of these two actions. END), you can terminate the session in which the query is running by using the PG_TERMINATE_BACKEND function. SELECT pg_terminate_backend(); SELECT pg_terminate_backend(54321); Once the blocking process is canceled, DROP TABLE query can get its lock and should run successfully. Abandoned replication slots: A replication slot is a data structure that keeps the PostgreSQL server from discarding information that is still needed by a … client application is hanging (or paused) and does not receive any data from the server, in this case keepalive works fine and the send() syscall will never end, even when a TERM signal was sent to it, because PostgreSQL is using SA_RESTARTflag for signal processing and SO_SNDTIMEO is not used at all (see man 7 signal). But sometimes it may not work and you may be forced to use more violent query: SELECT pg_terminate_backend(pid). general - pg_terminate_backend not working, pg_terminate_backend not working. The workaround i can see on the build machine is This set of commands ( create the dev too... And pg_terminate_backend in Section 9.26.2 for the SQL-callable equivalents of these two actions your VACUUM steps: Shutdown backends. 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