On Mon, 17 Mar 2025 at 12:18, Amit Kapila <amit.kapil...@gmail.com> wrote: > > On Mon, Mar 10, 2025 at 11:46 AM Shlok Kyal <shlok.kyal....@gmail.com> wrote: > > > > > > I tried to reproduce the scenario described using the following steps: > > > > Here are the steps: > > > > 1. set max_replication_slots = 2 > > > > 2. create two logical replication slot, lets say slot1 and slot2. drop > > the first slot (slot1). > > > > 3. Now run pg_copy_logical_replication slot function on slot2. Lets > > say copied slot is 'slot_cp'. > > In function copy_replication_slot add breakpoint just after function > > 'create_logical_replication_slot'. > > slot_cp will be created. In array > > ReplicationSlotCtl->replication_slots, slot_cp will come before slot2. > > > > 4. Now invalidate the 'slot2'. > > Function 'InvalidateObsoleteReplicationSlots' will be called. Now it > > will loop through ReplicationSlotCtl->replication_slots and will get > > 'slot_cp' first. Since the slot is acquired by copy_replication_slot, > > It will wait for the slot to be released. Once slot is released, > > 'slot_cp' and 'slot2' will be invalidated. > > > > It is also possible that InvalidateObsoleteReplicationSlots() has > already past slot_cp location in which case it doesn't need to wait > for the backend. > > I have changed the comments for the master branch patch. Do let me > know what you think of the attached change. If you agree with this, > then please prepare the patches for back-branches that reflect this > change. >
This change looks good to me. I have prepared the patches with the suggested changes for PG16, PG17 and master. I have also addressed the comments by Sawada-san in [1] and added a line in the commit message for PG15 and earlier version. [1]: https://www.postgresql.org/message-id/CAD21AoBtjj_xoH%2BpgHP_CKykj00fayjFqQ60W6az-Drj2%2BmOdQ%40mail.gmail.com Thanks and Regards, Shlok Kyal
master_v8-0001-Restrict-copying-of-invalidated-replication-slots.patch
Description: Binary data
REL_17_v8-0001-Restrict-copying-of-invalidated-replication-slots.patch
Description: Binary data
REL_16_v8-0001-Restrict-copying-of-invalidated-replication-slots.patch
Description: Binary data
