Re: Introduce XID age and inactive timeout based replication slot invalidation

Hi,

On Wed, Mar 27, 2024 at 02:55:17PM +0530, Bharath Rupireddy wrote:
> Please check the attached v27 patch which also has Bertrand's comment
> on deduplicating the TAP function. I've now moved it to Cluster.pm.

Thanks!

1 ===

+ Note that the slots on the standbys that are being synced from a
+ primary server (whose <structfield>synced</structfield> field is
+ <literal>true</literal>), will get the
+ <structfield>inactive_since</structfield> value from the
+ corresponding remote slot on the primary. Also, note that for the
+ synced slots on the standby, after the standby starts up (i.e. after
+ the slots are loaded from the disk), the inactive_since will remain
+ zero until the next slot sync cycle.

Not sure we should mention the "(i.e. after the slots are loaded from the disk)"
and also "cycle" (as that does not sound right in case of manual sync).

My proposal (in text) but feel free to reword it:

Note that the slots on the standbys that are being synced from a
primary server (whose synced field is true), will get the inactive_since value
from the corresponding remote slot on the primary. Also, after the standby starts
up, the inactive_since (for such synced slots) will remain zero until the next
synchronization.

2 ===

+=item $node->create_logical_slot_on_standby(self, primary, slot_name, dbname)

get_slot_inactive_since_value instead?

3 ===

+against given reference time.

s/given reference/optional given reference/?

Apart from the above, LGTM.

Regards,

--
Bertrand Drouvot
PostgreSQL Contributors Team
RDS Open Source Databases
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