RE: [CAUTION: SUSPECT SENDER] RE: [CAUTION: SUSPECT SENDER] RE: BUG #19029: Replication Slot size keeps increasing while logical subscription works fine - Mailing list pgsql-bugs

Dear Thadeus,

Thanks for sharing the info. From your screenshot, I can see that there is a
transaction 10861356 which modifies many tuples. Logical decoding has a mechanism
to spill a part of changes to the disk to avoid using much amount of memory and
it seems to be used here.

I think as next step we can clarify which process starts the transaction.  Can
you run below query when you reproduce the issue?

```
# SELECT * FROM pg_stat_activity WHERE backend_xid = '${XID}';
```

Files under pg_replslot/${slot_name} has a format: `xid-${XID}-lsn-${LSN_UPPER}-${LSN_LOWER}.spill`
so that ${XID} can be tuned when it happns. In your attached case, 10861356.

Best regards,
Hayato Kuroda
FUJITSU LIMITED