>> You can try to use and improve the --progress option in another patch
>> submission which shows how things are going.
> That'll certainly be useful, but won't solve this issue. The thing is
> that with asynchronous replication you need to know how long it takes
> until all nodes are back in sync, with no replication lag.
> I can probably do it with a custom pgbench script, but I'm tempted to
> add support for timing that part separately with a "wait command" to run
> at the end of the benchmark.
ISTM that a separate process not related to pgbench should try to monitor
the master-slave async lag, as it is an interesting information anyway...
However I'm not sure that pg_stat_replication currently has the necessary
information on either side to measure the lag (in time transactions, but
how do I know when a transaction was committed? or number of
transactions?).
--
Fabien.
