On Mon, Jan 22, 2024, at 4:06 AM, Hayato Kuroda (Fujitsu) wrote: > I analyzed and found a reason. This is because publications are invisible for > some transactions. > > As the first place, below operations were executed in this case. > Tuples were inserted after getting consistent_lsn, but before starting the > standby. > After doing the workload, I confirmed again that the publication was created. > > 1. on primary, logical replication slots were created. > 2. on primary, another replication slot was created. > 3. ===on primary, some tuples were inserted. === > 4. on standby, a server process was started > 5. on standby, the process waited until all changes have come. > 6. on primary, publications were created. > 7. on standby, subscriptions were created. > 8. on standby, a replication progress for each subscriptions was set to given > LSN (got at step2). > =====pg_subscriber finished here===== > 9. on standby, a server process was started again > 10. on standby, subscriptions were enabled. They referred slots created at > step1. > 11. on primary, decoding was started but ERROR was raised.
Good catch! It is a design flaw. > In this case, tuples were inserted *before creating publication*. > So I thought that the decoded transaction could not see the publication > because > it was committed after insertions. > > One solution is to create a publication before creating a consistent slot. > Changes which came before creating the slot were surely replicated to the > standby, > so upcoming transactions can see the object. We are planning to patch set to > fix > the issue in this approach. I'll include a similar code in the next patch and also explain why we should create the publication earlier. (I'm renaming create_all_logical_replication_slots to setup_publisher and calling create_publication from there and also adding the proposed GUC checks in it.) -- Euler Taveira EDB https://www.enterprisedb.com/
