Re: Introduce XID age based replication slot invalidation

Hello,

Thanks for the v5 patch set, I have reviewed and did initial testing on
v5 patch set, and it LGTM, except these

diff --git a/src/backend/replication/slot.c b/src/backend/replication/slot.c
index 286f0f46341..c2ff7e464f0 100644
--- a/src/backend/replication/slot.c
+++ b/src/backend/replication/slot.c
@@ -1849,7 +1849,7 @@
ReportSlotInvalidation(ReplicationSlotInvalidationCause cause,
                                else
                                {
                                        /* translator: %s is a GUC variable
name */
-                                       appendStringInfo(&err_detail,
_("The slot's xmin %u is %d transactions old, which exceeds the configured
\"%s\" value of %d."),
+                                       appendStringInfo(&err_detail,
_("The slot's catalog_xmin %u is %d transactions old, which exceeds the
configured \"%s\" value of %d."),

 catalog_xmin, (int32) (recentXid - catalog_xmin), "max_slot_xid_age",
max_slot_xid_age);
                                }

while testing the active slot XID age invalidation (SIGTERM path) , i
observed that slot got invalidated , walsender was killed because of
SIGTERM , then starts the infinite-retry-cycle problem where
walreceiver starts walsender and walsender will try to use an invalidated
slot and dies, will think more on this.

-- 
Thanks,
Srinath Reddy Sadipiralla
EDB: https://www.enterprisedb.com/