Re: Refactor pg_rewind code and make it work against a standby

On 15/11/2020 09:07, Tom Lane wrote:
> I wrote:
>> Not sure if you noticed, but piculet has twice failed the
>> 007_standby_source.pl test that was added by 9c4f5192f:
>> ...
>> Now, I'm not sure what to make of that, but I can't help noticing that
>> piculet uses --disable-atomics while francolin uses --disable-spinlocks.
>> That leads the mind towards some kind of low-level synchronization
>> bug ...
> 
> Or, maybe it's less mysterious than that.  The failure looks like we
> have not waited long enough for the just-inserted row to get replicated
> to node C.  That wait is implemented as
> 
>     $lsn = $node_a->lsn('insert');
>     $node_b->wait_for_catchup('node_c', 'write', $lsn);
> 
> which looks fishy ... shouldn't wait_for_catchup be told to
> wait for replay of that LSN, not just write-the-WAL?

Yep, quite right. Fixed that way, thanks for the debugging!

- Heikki