Dear Max, Thanks for the report.
> The initial snapshot and data copy complete successfully for all tables. > However, anywhere from 5 > minutes to 2 hours after the initial sync, the subscription consistently > fails with memory allocation errors like: > > ``` > 2025-06-10 14:14:56.800 UTC [299] ERROR: could not receive data from WAL > stream: ERROR: invalid memory alloc request size 1238451248 > 2025-06-10 14:14:56.805 UTC [1] LOG: background worker "logical replication > worker" (PID 299) exited with exit code 1 > ``` I think this is a known postgres bug which has been also reported at [1]. We are discussing how we fix. Typically this can happen when there are lots of concurrent transactions and they have DDLs. IIUC there are no good workaround for now - any parameters can't avoid the failure. Only you can reduce them. I'm happy if you apply the patch posted at [1] and confirms the issue can be solved, but... seems difficult because you are in the managed env. [1]: https://www.postgresql.org/message-id/CALDaNm0TaTPuza7Fa%2BDRMzL%2BmqK3%2B7RVEvFiRoDJbU2vkJESwg%40mail.gmail.com Best regards, Hayato Kuroda FUJITSU LIMITED
