Re: [HACKERS] Restricting maximum keep segments by repslots

On 2020-Apr-08, Kyotaro Horiguchi wrote:

> I understand how it happens.
> 
> The latch triggered by checkpoint request by CHECKPOINT command has
> been absorbed by ConditionVariableSleep() in
> InvalidateObsoleteReplicationSlots.  The attached allows checkpointer
> use MyLatch for other than checkpoint request while a checkpoint is
> running.

Hmm, that explanation makes sense, but I couldn't reproduce it with the
steps you provided.  Perhaps I'm missing something.

Anyway I think this patch should fix it also -- instead of adding a new
flag, we just rely on the existing flags (since do_checkpoint must have
been set correctly from the flags earlier in that block.)

I think it'd be worth to verify this bugfix in a new test.  Would you
have time to produce that?  I could try in a couple of days ...

-- 
Álvaro Herrera                https://www.2ndQuadrant.com/
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