On Tue, May 9, 2017 at 9:18 AM, Petr Jelinek <petr.jeli...@2ndquadrant.com> wrote:
> On 08/05/17 13:47, Petr Jelinek wrote: > > On 08/05/17 01:17, Jeff Janes wrote: > >> After dropping a subscription, it says it succeeded and that it dropped > >> the slot on the publisher. > >> > >> But the publisher still has the slot, and a full-tilt process described > >> by ps as > >> > >> postgres: wal sender process jjanes [local] idle in transaction > >> > >> Strace shows that this process is doing nothing but opening, reading, > >> lseek, and closing from pg_wal, and calling sbrk. It never sends > anything. > >> > >> This is not how it should work, correct? > >> > > > > No, and I don't see how this happens though, we only report success if > > the publisher side said that DROP_REPLICATION_SLOT succeeded. So far I > > don't see anything in source that would explain this. I will need to > > reproduce it first to see what's happening (wasn't able to do that yet, > > but it might just need more time since you say it does no happen always). > > > > Hm I wonder are there any workers left on subscriber when this happens? > Yes. using ps, I get this: postgres: bgworker: logical replication worker for subscription 16408 sync 16391 postgres: bgworker: logical replication worker for subscription 16408 sync 16388 They seem to be permanently blocked on a socket to read from the publisher. On the publisher side, I think it is very slowly assembling a snapshot. It seems to be adding one xid at a time, and then re-sorting the entire list. Over and over. Cheers, Jeff
