Re: Creating many tables gets logical replication stuck

On Tue, 2020-08-25 at 15:44 +0300, Achilleas Mantzios wrote:
> Hello Keisuke
> On 25/8/20 9:50 π.μ., Keisuke Kuroda wrote:
> > Hi All,
> >
> > There was a similar problem in this discussion:
> > Logical decoding CPU-bound w/ large number of tables
> > https://www.postgresql.org/message-id/flat/CAHoiPjzea6N0zuCi%3D%2Bf9v_j94nfsy6y8SU7-%3Dbp4%3D7qw6_i%3DRg%40mail.gmail.com
> >
> > > RelfilenodeMapHash from 1024 entries to 64.
> > The above changes reduced the performance impact.
> >
> > However, I think the problem that there are too
> > many invalidations of RelfilenodeMapHash still remains.
> > As you report, when many tables are created/dropped/truncated,
> Right! IIRC also a massive drop created the very same problem during the latest attempts for reproduction but I did not focus on this scenario.
> > The walsender process can get stuck.

Thanks you both, that is indeed the same problem, and the linked thread helps understand the problem.

Yours,
Laurenz Albe