| From: | Daniel Gustafsson <daniel(at)yesql(dot)se> |
|---|---|
| To: | lxiaogang5 <lxiaogang5(at)gmail(dot)com> |
| Cc: | pgsql-bugs <pgsql-bugs(at)postgresql(dot)org> |
| Subject: | Re: There is a defect in the ReplicationSlotCreate() function where it iterates through ReplicationSlotCtl->replication_slots[max_replication_slots] to find a slot but does not break out of the loop when a slot is found. |
| Date: | 2025-01-14 10:57:34 |
| Message-ID: | D57D44E8-C6FE-41FD-9D43-105BB9B73366@yesql.se |
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| Thread: | |
| Lists: | pgsql-bugs |
> On 14 Jan 2025, at 05:24, lxiaogang5 <lxiaogang5(at)gmail(dot)com> wrote:
> There is a logical defect in the function ReplicationSlotCreate (creating a new slot) when it internally traverses the ReplicationSlotCtl->replication_slots[max_replication_slots] array. When an available slot is found (slot = s), it should break the current for loop. This issue still exists in the latest code, resulting in wasted CPU resources.
We could exit early, but any system which max_replication_slots set high enough
that the savings are measurable in a non-hot codepath is likely having other
performance problems as well (max_replication_slots is by default 10).
If you feel strongly about I suggest creating a patch and submitting. Also,
please don't send 6Mb images of text when simply copy/paste of the text would
have worked even better.
--
Daniel Gustafsson