On Mon, 2023-11-13 at 17:06 -0800, Benjamin Leis wrote: > I'm looking at a pg_stat_activity dump where there are a group of active > threads stuck for a long time in MessageQueueSend > 7:52.394089+00 | IPC | MessageQueueSend | active | > | 27406510 | -5892847938856697008 | SELECT .... > Does this mean they are blocked on clients reading data or does it > represent something blocking on the server side? That's something on the server: a parallel worker process is waiting to send data to the parallel leader process. Look for the "leader_pid" column in the "pg_stat_activity" line above and see what that process is doing. I wouldn't worry about a parellel worker in that state, as long as there is no problem with the parallel leader. Yours, Laurenz Albe
