[Gluster-Maintainers] inclusion of multi-threaded self-heal feature in 3.7.12

[Niels de Vos]

On Tue, Apr 12, 2016 at 11:50:23AM +0530, Pranith Kumar Karampuri wrote:
> 
> 
> On 04/11/2016 09:58 PM, Vijay Bellur wrote:
> >On 04/11/2016 08:02 AM, Niels de Vos wrote:
> >>On Mon, Apr 11, 2016 at 05:00:22PM +0530, Pranith Kumar Karampuri wrote:
> >>>hi,
> >>>         I am thinking of getting multi-threaded self-heal patch in
> >>>3.7.12
> >>>release as it is not a big code change, could you let me know if
> >>>anyone has
> >>>any issues with this?
> >>
> >>Is this safe to use when there is no rpc throttling?
> Default number of parallel heals is still '1'. It will be 1 until we have
> some form of throttling of traffic, which we are targeting for 3.8.
> 
> >>
> >
> >A few more questions:
> >
> >1. What is the impact on stability due to this patch?
> So far we haven't found any problems with this patch. It has been tested for
> around a month before it is sent upstream for merge.
> >
> >2. What scenarios would we want this feature to be turned on? Basically an
> >admin guide update about these scenarios would be useful.
> I can send a document about this.
> >
> >3. What kind of tests have been done with this feature?
> Most of the tests include perf comparison of VM images/sharded images which
> showed promising results.
> >
> >4. Are there tests that we want to cover but have not been able to
> >complete for this feature?
> Hmm... not really.

I'm not completely confident that this should be backported to 3.7. We
should focus on backporting bug fixes and leave the featurs for next
releases. We have seen a few regression in the 3.7 stable branch because
of agressive backporting of features. Potential undiscovered issues are
something we should expect for each new feature, and backporting them
always comes with a risk. I really want to keep the promise to users
that 3.7 is a stable version.

You have to come with really good arguments to convince anyone from
including a feature in stable branches. Disabling (or in this case one
parallel heal) does not make much for backports.

Try again? Thanks,
Niels
-------------- next part --------------
A non-text attachment was scrubbed...
Name: signature.asc
Type: application/pgp-signature
Size: 819 bytes
Desc: not available
URL: <http://www.gluster.org/pipermail/maintainers/attachments/20160412/10ddf518/attachment.sig>