[Gluster-devel] [geo-rep] Adding broken changelog into OLD htime file

[Vijay Bellur]

On 02/23/2015 04:25 PM, Saravanakumar Arumugam wrote:
> Hi,
> Geo-replication make use of changelog translator (which is used to
> capture all I/O operations happening in a Volume and this happens per
> brick).
> All the I/O operations happening are stored in
> .glusterfs/changelogs/CHANGELOG.TS (where TS is timestamp).
> All successful changelogs(in a session) are getting logged into HTIME file.
>
> Now, we have a case where the Brick can go down (for example some crash)
> and Changelog logging stops.
>
> Consider, gluster volume is started again.
> Now, the last CHANGELOG (which captured I/Os just before crash) is
> getting included into the new HTIME file.
> This leads to inconsistent timings. The last CHANGELOG should have been
> included into the previous HTIME file.
>
> I am planning to make changes in changelog translator so that the last
> CHANGELOG will be included
> into the previous HTIME file.  It will be renamed as CHANGELOG.<Previous
> Changelog TS + 1>.

Would this be done as part of the init() routine for changelog xlator?

>
> This will give better results when changes happened across a specific
> duration is asked for.
>

Looks good to me.

Thanks,
Vijay