On Fri, Mar 4, 2011 at 7:51 PM, Simon Riggs <simon@2ndquadrant.com> wrote:
>> + if (walsnd->pid != 0 &&
>> + walsnd->sync_standby_priority > 0 &&
>> + (priority == 0 ||
>> + priority < walsnd->sync_standby_priority))
>> + {
>> + priority = walsnd->sync_standby_priority;
>> + syncWalSnd = walsnd;
>> + }
>>
>> According to the code, the last named standby has highest priority. But the
>> document says the opposite.
>
> Priority is a difficult word here since "1" is the highest priority. I
> deliberately avoided using the word "highest" in the code for that
> reason.
>
> The code above finds the lowest non-zero standby, which is correct as
> documented.
Hmm.. that seems to find the highest standby. And, I could confirm
that in my box. Please see the following. The priority (= 2) of
synchronous standby (its sync_state is SYNC) is higher than that (= 1)
of potential one (its sync_state is POTENTIAL).
postgres=# SHOW synchronous_standby_names ;synchronous_standby_names
---------------------------one, two
(1 row)
postgres=# SELECT application_name, state, sync_priority, sync_state
FROM pg_stat_replication;application_name | state | sync_priority | sync_state
------------------+-----------+---------------+------------one | STREAMING | 1 | POTENTIALtwo
| STREAMING | 2 | SYNC
(2 rows)
Regards,
--
Fujii Masao
NIPPON TELEGRAPH AND TELEPHONE CORPORATION
NTT Open Source Software Center
