dineshkumar02 / ptor Goto Github PK

Hi everyone!

I tested the utility on a Patroni cluster. And found that the calculation of data loss is not very correct in my opinion. With synchronous_commit: on and remote_write settings we are getting message that we have a data loss. If we insert a 10s delay before the data loss calculation, the calculation is correct.

This is due to the fact that when failover happened, we immediately read the data from the new primary, without taking into account that the promote has not reached the end and not all WALs have been replayed during the promote.
As a result, we get a message about data loss, while with a delay there is no such message. I don't think this is a bug. But we need to think how to get application into new primary, if without delay we get a non-consistent read, if with some RTO+delta delay we are fine.

From the utility perspective, only the remote_apply option guarantees us data consistency on the synchronous standby, which is not exactly accurate :)