On 2020/06/23 18:42, Kyotaro Horiguchi wrote:
At Tue, 23 Jun 2020 00:17:47 +0900, Fujii Masao <masao.fu...@oss.nttdata.com>
wrote in
Hi,
If restart_lsn of logical replication slot gets behind more than
max_slot_wal_keep_size from the current LSN, the logical replication
slot would be invalidated and its restart_lsn is reset to an invalid
LSN.
If this logical replication slot with an invalid restart_lsn is
specified
as the source slot in pg_copy_logical_replication_slot(), the function
causes the following assertion failure.
Good catch!
TRAP: FailedAssertion("!logical_slot", File: "slotfuncs.c", Line: 727)
This assertion failure is caused by
/* Copying non-reserved slot doesn't make sense */
if (XLogRecPtrIsInvalid(src_restart_lsn))
ereport(ERROR,
(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
errmsg("cannot copy a replication slot that
doesn't reserve
WAL")));
I *guess* this assertion check was added because restart_lsn should
not be invalid before. But in v13, it can be invalid thanks to
max_slot_wal_keep_size.
I think that this assertion check seems useless and should be removed
in v13.
Patch attached. Thought?
Your diagnosis looks correct to me.
Thanks for the check! I will commit the patch later.
The assertion failure means that
copy_replication_slot was not exercised at least for a non-reserving
logical slots. Greping "pg_copy_logical_replication_slot" on src/test
showed nothing so I doubt we are exercising the function.
Don't we need some?
Yes, increasing the test coverage sounds helpful!
Regards,
--
Fujii Masao
Advanced Computing Technology Center
Research and Development Headquarters
NTT DATA CORPORATION
