Hi, We have a customer that for the second time have most of its logical replicas (13 of 16) in a catchcup state, they have been working fine for some time now and suddenly the pg_stat_replication view shows something like this for all of the replicas in catchup state:
""" pid | 2667517 state | catchup sent_lsn | 38B4/67C403A8 write_lsn | 38B7/D2C9C038 flush_lsn | 38B7/D2C9C038 replay_lsn | 38B7/D2C9C038 """ This doesn't make sense for me. This is 16.9 btw. The pg_stat_activity says: """ wait_event_type | IO wait_event | ReorderBufferWrite state | active backend_xid | backend_xmin | query_id | query | START_REPLICATION SLOT "sub_down_tables" LOGICAL 38B7/CEBC9330 (proto_version '4', origin 'any', publication_names '"pub_down_tables"') backend_type | walsender """ And the logs keeps showing this: """ 2025-12-26 12:17:41.861 -05 [pid=2667517;l=1;tx=0] LOG: 38B7/CEBC9330 has been already streamed, forwarding to 38B7/D2C9C038 2025-12-26 12:17:41.861 -05 [pid=2667517;l=2;tx=0] STATEMENT: START_REPLICATION SLOT "sub_down_tables_central_trx001" LOGICAL 38B7/CEBC9330 (proto_version '4', origin 'any', publication_names '"pub_elipsys_cresio_down_tables"') 2025-12-26 12:17:41.867 -05 [pid=2667517;l=3;tx=0] LOG: starting logical decoding for slot "sub_down_tables_central_trx001" 2025-12-26 12:17:41.867 -05 [pid=2667517;l=4;tx=0] DETAIL: Streaming transactions committing after 38B7/D2C9C038, reading WAL from 38B0/2261B890. 2025-12-26 12:17:41.867 -05 [pid=2667517;l=5;tx=0] STATEMENT: START_REPLICATION SLOT "sub_down_tables_central_trx001" LOGICAL 38B7/CEBC9330 (proto_version '4', origin 'any', publication_names '"pub_elipsys_cresio_down_tables"') 2025-12-26 12:17:41.868 -05 [pid=2667517;l=6;tx=0] LOG: logical decoding found consistent point at 38B0/2261B890 2025-12-26 12:17:41.868 -05 [pid=2667517;l=7;tx=0] DETAIL: Logical decoding will begin using saved snapshot. 2025-12-26 12:17:41.868 -05 [pid=2667517;l=8;tx=0] STATEMENT: START_REPLICATION SLOT "sub_down_tables_central_trx001" LOGICAL 38B7/CEBC9330 (proto_version '4', origin 'any', publication_names '"pub_elipsys_cresio_down_tables"') 2025-12-26 12:30:35.953 -05 [pid=2678504;l=1;tx=0] ERROR: replication slot "sub_down_tables_central_trx001" is active for PID 2667517 2025-12-26 12:30:40.959 -05 [pid=2678564;l=1;tx=0] ERROR: replication slot "sub_down_tables_central_trx001" is active for PID 2667517 """ any idea what to check? -- Jaime Casanova SYSTEMGUARDS S.A.
