RE: Logical replication 'invalid memory alloc request size 1585837200' after upgrading to 17.5

Dear Sawada-san,

> I think the reason why we execute all invalidation messages even in
> non concurrent abort cases is that we need to invalidate all caches as
> well that are loaded during the replay. Consider the following
> sequences:
> 
> 1)  S1: CREATE TABLE d (data text not null);
> 2)  S1: INSERT INTO d VALUES ('d1');
> 3)      S2: BEGIN; INSERT INTO d VALUES ('d2');
> 4)          S3: BEGIN; INSERT INTO d VALUES ('d3');
> 5)  S1: ALTER PUBLICATION pb ADD TABLE d;
> 6)      S2: INSERT INTO d VALUES ('d4');
> 7)      S2: COMMIT;
> 8)          S3: COMMIT;
> 9)    S2: INSERT INTO d VALUES('d5');
> 10) S1: INSERT INTO d VALUES ('d6');
> 
> When replaying S2's first transaction at 7), we decode the insert from
> 3) using the snapshot which is from before the ALTER, creating the
> cache for table 'd'. Then we invalidate the cache by the inval message
> distributed from S1's the ALTER and then build the relcache again when
> decoding the insert from 6). The cache is the state after the ALTER.
> When replaying S3's transaction at 8), we should decode the insert
> from 4) using the snapshot which is from before the ALTER. Since we
> call ReorderBufferExecuteInvalidations() also in non concurrent abort
> paths, we can invalidate the relcache built when decoding the insert
> from 6). If we don't include the inval message distributed from 5) to
> txn->invalidations, we don't invalidate the relcache and end up
> sending the insert from 4) even though it happened before the ALTER.

Thanks for giving another scenario. Let me test this workload and share result later.


Best regards,
Hayato Kuroda
FUJITSU LIMITED