On Thursday, November 28, 2024 8:16 PM Alvaro Herrera <alvhe...@alvh.no-ip.org> wrote: > > Gabriele just reported a crash when changing synchronized_standby_slots > under SIGHUP and logging collector working. The problem apparently is > that validate_sync_standby_slots is run for the GUC check routine, and > it requires acquiring an LWLock; but syslogger doesn't have a PGPROC so > that doesn't work. > > Apparently we already have a hack in place against the same problem in > postmaster (and elsewhere?), by testing that ReplicationSlotCtl is not > null. But that hack seems to be incomplete, as the crash here attests. > > To reproduce, simply start with no synchronized_standby_slots setting > and logging_collector=on, then change the value in postgresql.conf and > reload. > > One option to fix this might be as attached. The point here is that > processes without a PGPROC don't need or care to have a correct setting, > so we just skip verifying it on those. AFAICS this is more general than > the test for ReplicationSlotCtl, so I just removed that one.
Thanks for the fix! It looks good to me. I can also reproduce this bug and confirmed that the bug is fixed after applying the patch. In addition to the regression tests, I also manually tested the behavior of the postmaster, walsender, and user backend after reloading the configuration, and they all work as expected. Best Regards, Hou zj
