Dear Thadeus,
> Under the pg_replslot folder, each replication slot's folder increased
> simultaneously. There were 12 folders (two publications, six subscribers), and
> the total size increase was about 420 GB).
Oh, I misunderstood like that number of WAL files increased.
Let me do some more questions to diagnose your system.
Can you share us the logical_decoding_work_mem on the publisher side? You can obtain via:
```
SHOW logical_decoding_work_mem;
```
Also, when you succeeded to reproduce, can you run the below command to see the
conent of the directory? ${DATA_PUB} can be tuned based on your environment.
```
du -sh ${DATA_PUB}/pg_replslot/*/*
```
This can see for which file uses the disk so much.
Best regards,
Hayato Kuroda
FUJITSU LIMITED