[heketi-devel] Heketi HA using Kubernetes

Gaurav Chhabra varuag.chhabra at gmail.com
Thu Sep 28 17:39:25 UTC 2017


​Hi Jose,


Thanks for the response. That was quite helpful.​ So in our case, there
will not be frequent volume create/delete. Not at all. Once done during
initial setup, it should continue unless we face some space crunch. :)
Based on your quote that *actual I/O* will not be interrupted/affected, it
seems running a single node Heketi cluster in Kubernetes should be just
fine.


Thank You! :)
Gaurav


On Thu, Sep 28, 2017 at 9:58 PM, Jose A. Rivera <jarrpa at redhat.com> wrote:

> In regular usage the heketi service is only used for the creation and
> deletion of GlusterFS volumes. That is, only as PV/PVC pairs are
> created or deleted. heketi's presence is not needed for when
> applications want to mount and read/write to the volumes. If you have
> a constant stream of volume create/delete requests then yes you'll
> experience a few seconds of service interruption, but the actual I/O
> work would not be affected.
>
> --Jose
>
> On Thu, Sep 28, 2017 at 9:28 AM, Gaurav Chhabra
> <varuag.chhabra at gmail.com> wrote:
> > Hi Talur,
> >
> >
> > Since there will be many applications which will be using Gluster
> volumes, i
> > would really prefer if i could ensure maximum availability. From what i
> > understand, since Heketi is managing Gluster and while creating storage
> > class, we specify the Heketi REST URL, so if it goes down, i hope
> > application pods will be affected, isn't it? If replicas is not feasible,
> > what are the options i can explore?
> >
> >
> > Regards,
> > Gaurav
> >
> >
> > On Thu, Sep 28, 2017 at 5:39 PM, Raghavendra Talur <rtalur at redhat.com>
> > wrote:
> >>
> >> On Wed, Sep 27, 2017 at 11:15 PM, Gaurav Chhabra
> >> <varuag.chhabra at gmail.com> wrote:
> >> > Hello Everyone,
> >> >
> >> >
> >> > I want to install Heketi server and client on Kubernetes. To ensure
> HA,
> >> > i
> >> > would like to have replica set to 2 for it. However, i am not sure
> about
> >> > the
> >> > Heketi db. Does it contain only static data about volumes, nodes etc
> >> > (and
> >> > changes only when we perform some explicit operations such as add
> >> > volumes
> >> > etc) OR will it create issues (concurrent write) if i have two
> replicas
> >> > running?
> >> >
> >>
> >> Yes, heketi updates the db only when a operation is performed. But
> >> replica set 2 won't work because bolt db opens the db file with read
> >> write lock and the second instance will fail to get one. You will end
> >> up with 2nd instance in read only mode.
> >>
> >> If I get it right, you are saying you can't afford to have heketi pod
> >> down even for the time duration when kubernetes respins the pod when
> >> it detects it is down?
> >>
> >> >
> >> > Thanks,
> >> > Gaurav
> >> >
> >> > _______________________________________________
> >> > heketi-devel mailing list
> >> > heketi-devel at gluster.org
> >> > http://lists.gluster.org/mailman/listinfo/heketi-devel
> >> >
> >
> >
> >
> > _______________________________________________
> > heketi-devel mailing list
> > heketi-devel at gluster.org
> > http://lists.gluster.org/mailman/listinfo/heketi-devel
> >
>
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