[Gluster-users] Synchronous replication, or no?

[Vijay Bellur]

On 04/09/2015 07:33 PM, Jeff Darcy wrote:
>> I was under the impression that gluster replication was synchrounous, so the
>> appserver would not return back to the client until the created file was
>> replicated to the other server. But this does not seem to be the case,
>> because sleeping a little bit always seems to make the read failures go
>> away. Is there any other reason why a file created is not immediately
>> available on a second request?
>
> It's quite possible that the replication is synchronous (the bits do hit
> disk before returning) but that the results are not being seen immediately
> due to caching at some level.  There are some GlusterFS mount options
> (especially --negative-timeout) that might be relevant here, but it's also
> possible that the culprit is somewhere above that in your app servers.
>

Might be worth mounting with --entry-timeout=0 too.

-Vijay