Re: [COMMITTERS] pgsql: Efficient transaction-controlled synchronous replication.

On Mon, Mar 7, 2011 at 6:20 PM, Simon Riggs <simon(at)2ndquadrant(dot)com> wrote:
> On Mon, 2011-03-07 at 17:27 +0900, Fujii Masao wrote:
>> On Mon, Mar 7, 2011 at 7:51 AM, Simon Riggs <simon(at)2ndquadrant(dot)com> wrote:
>
>> And,, I found one bug ;) You seem to have wrongly removed the check
>> of max_wal_senders in SyncRepWaitForLSN. This can make the
>> backend wait for replication even if max_wal_senders = 0. I could produce
>> this problematic situation in my machine. The attached patch fixes this problem.
>
> There may be a bug, but that's not the fix.
>
> I spotted that issue myself in testing. I put in a protection to stop
> setting synchronous_standby_names if max_wal_senders is zero, with error
> message.
>
> Are you saying the committed version doesn't trigger that ERROR?

I changed synchronous_standby_names after startup and reloaded the
configuration file. So I didn't encounter such an error message.

Regards,

--
Fujii Masao
NIPPON TELEGRAPH AND TELEPHONE CORPORATION
NTT Open Source Software Center