I wrote: > Alvaro Herrera <alvhe...@2ndquadrant.com> writes: >> Tom Lane wrote: >>> Hm. Do you have a more-portable alternative?
>> I was thinking in a WaitEventSet from latch.c. My first reaction was that that sounded like a lot more work than removing two lines from maybe_start_bgworker and adjusting some comments. But on closer inspection, the slow-bgworker-start issue isn't the only problem here. On a machine that restarts select()'s timeout after an interrupt, as (at least) HPUX does, the postmaster will actually never iterate ServerLoop's loop except immediately after receiving a new connection request. The stream of interrupts from the autovac launcher is alone sufficient to prevent the initial 60-second timeout from ever elapsing. So if there are no new connection requests for awhile, none of the housekeeping actions in ServerLoop get done. Most of those actions are concerned with restarting failed background tasks, which is something we could get by without --- it's unlikely that those tasks would fail without causing a database-wide restart, and then there really isn't going to be much need for them until at least one new connection request has arrived. But the last step in that loop is concerned with touching the sockets and lock files to prevent aggressive /tmp cleaners from removing them, and that's something that can't be let slide, or we might as well not have the logic at all. I've confirmed experimentally that on my HPUX box, a postmaster not receiving new connections for an hour or more in fact fails to update the mod times on the sockets and lock files. So that problem isn't hypothetical. So it's looking to me like we do need to do something about this, and ideally back-patch it all the way. But WaitEventSet doesn't exist before 9.6. Do we have the stomach for back-patching that into stable branches? regards, tom lane -- Sent via pgsql-hackers mailing list (email@example.com) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers