Thank you for the answers. I'm still confused. If fsync is not replicated to the slave, then how is replication affected by a corrupt master? If the master dies and there's a commit recorded in the wal log that didn't actually happen, wouldn't the slave still be expected to be in a sane state, with the wal logs accurately reflecting what's on disk?
Maybe I just don't understand streaming replication enough. The docs seem to say that synchronous commits mean that the slave also has to verify a write before a transaction is considered complete. How does fsync affect the way/order in which statements are sent to the slave for replication?On Thu, Oct 24, 2013 at 9:42 AM, Alban Hertroys <haramrae@xxxxxxxxx> wrote:
On 24 October 2013 15:04, Fujii Masao <masao.fujii@xxxxxxxxx> wrote:
> On Thu, Oct 24, 2013 at 10:39 AM, <maillists0@xxxxxxxxx> wrote:
>> Am I wrong? If I'm wrong, is there still danger to the slaveCorruption due to fsync being off on the master will be replicated to
>> in this kind of setup?
>
> No, I think.
the slave, or - if corruption is bad enough - replication will fail to
replicate affected records entirely. Of course, turning fsync off is
no guarantee for corruption - it's the other way around: having it on
guarantees that you don't get corruption (provided that... etc).
You could disable replication while fsync is off. I'd verify the data
on the master (by creating a dump, for example) before re-enabling it
again, though.
--
If you can't see the forest for the trees,
Cut the trees and you'll see there is no forest.
