On Wed, Apr 16, 2025 at 10:30 AM shveta malik <shveta.ma...@gmail.com> wrote: > > On Wed, Mar 26, 2025 at 4:17 PM Zhijie Hou (Fujitsu) > <houzj.f...@fujitsu.com> wrote: > > > > Here's a rebased version of the patch series. > > >
Few comments for patch004: Config.sgml: 1) + <para> + Maximum duration (in milliseconds) for which conflict + information can be retained for conflict detection by the apply worker. + The default value is <literal>0</literal>, indicating that conflict + information is retained until it is no longer needed for detection + purposes. + </para> IIUC, the above is not entirely accurate. Suppose the subscriber manages to catch up and sets oldest_nonremovable_xid to 100, which is then updated in slot. After this, the apply worker takes a nap and begins a new xid update cycle. Now, let’s say the next candidate_xid is 200, but this time the subscriber fails to keep up and exceeds max_conflict_retention_duration. As a result, it sets oldest_nonremovable_xid to InvalidTransactionId, and the launcher skips updating the slot’s xmin. However, the previous xmin value (100) is still there in the slot, causing its data to be retained beyond the max_conflict_retention_duration. The xid 200 which actually honors max_conflict_retention_duration was never marked for retention. If my understanding is correct, then the documentation doesn’t fully capture this scenario. 2) + The replication slot + <quote><literal>pg_conflict_detection</literal></quote> that used to + retain conflict information will be invalidated if all apply workers + associated with the subscription, where Subscription --> subscriptions 3) Name stop_conflict_retention in MyLogicalRepWorker is confusing. Shall it be stop_conflict_info_retention? thanks Shveta
