Hi,
> This test is completely meaningless. Just as you wouldn't set
> innodb_redo_log_capacity=Minimum Value,
> innodb_max_dirty_pages_pct=Minimum Value
> You used an extreme example to prove the double write.Why didn't you
> compare using best practices?
I wouldn't be so quick to dismiss these results. The configuration
was deliberately chosen to trigger more frequent checkpoints. As I
mentioned in my initial email, more frequent checkpoints strictly bound
the amount of WAL that needs to be replayed, resulting in much faster
crash recovery.
The entire ARIES paper heavily emphasizes optimizing crash recovery
time in database design. Minimizing recovery time is a fundamental
database capability, and we shouldn't rely solely on High Availability
(HA) switchovers to mask or solve crash recovery problems.
Actually, I have always felt that PostgreSQL's minimum limit of 30s
for `checkpoint_timeout` is a bit too restrictive. Ideally, the system
should allow for even higher frequency checkpoints. Setting it to a
lower value, such as 10s, could achieve the exact same effect of
strictly bounding recovery time. This test simulates an environment
where a very aggressive RTO (Recovery Time Objective) is required,
which is a highly practical scenario, not just an extreme edge case.
Regards,
Baotiao
