Re: Synchronous commit behavior during network outage

On 20.04.2021 19:38, Tomas Vondra wrote:
>
> On 4/20/21 6:23 PM, Aleksander Alekseev wrote:
>> Hi Ondřej,
>>
>> Thanks for the report. It seems to be a clear violation of what is
>> promised in the docs. Although it's unlikely that someone implemented
>> an application which deals with important data and "pressed Ctr+C" as
>> it's done in psql. So this might be not such a critical issue after
>> all. BTW what version of PostgreSQL are you using?
>>
> Which part of the docs does this contradict?


I think, Aleksandr refers to the following phrase in docs:

"The guarantee we offer is that the application will not receive 
explicit acknowledgment of the successful commit of a transaction until 
the WAL data is known to be safely received by all the synchronous 
standbys." [1]

And IMO confusing here regards to the notion of `successful commit`. 
Does warning attached to received commit message make it not 
*successful*? I think we have to explicitly mention cases about 
cancellation and termination session in docs to avoid ambiguity in 
understanding of phrase above.


1. 
https://www.postgresql.org/docs/current/warm-standby.html#SYNCHRONOUS-REPLICATION-HA

-- 
Regards,
Maksim Milyutin