[Gluster-devel] New commands for supporting add/remove brick and rebalance on tiered volume

[Hari Gowtham]

Hi Atin,
Yes, we can do it. the existing semantics need some changes because of the 
attach tier command (gluster volume tier <VOLNAME> attach <BRICK>...) the 
parsing has to be changed to accommodate the attach tier command. if used as I 
mentioned then we can use the functions of attach tier generic for adding brick
also. Other thing with using args is. it needs changes to support the keywords 
like replica <count> also. so when we try to make a generic function for add 
brick on tiered volume and attach tier these keywords like replica <count> and 
tier-type <hot/cold> will need more changes.  

So i feel its better to have a separate command instead of the args.  
If i have been missing any pros from having the args let me know.

----- Original Message -----
> From: "Atin Mukherjee" <amukherj at redhat.com>
> To: "Hari Gowtham" <hgowtham at redhat.com>
> Cc: "gluster-devel" <gluster-devel at gluster.org>, "gluster-users" <gluster-users at gluster.org>
> Sent: Monday, October 3, 2016 2:31:40 PM
> Subject: Re: [Gluster-devel] New commands for supporting add/remove brick and rebalance on tiered volume
> 
> On Mon, Oct 3, 2016 at 12:21 PM, Hari Gowtham <hgowtham at redhat.com> wrote:
> 
> > Hi,
> >
> > The current add and remove brick commands aren't sufficient to support
> > add/remove brick on tiered volumes.So the commands need minor changes
> > like mentioning which tier we are doing the operation on. So in order
> > to specify the tier on which we are performing the changes, I thought
> > of using the following commands for add and remove brick
> >
> > adding brick on tiered volume:
> > gluster volume tier <volname> add-hot-brick/add-cold-brick <brick> ...
> > <force>
> >
> > removing brick on tierd volume:
> > gluster volume tier <volname> remove-hot-brick/remove-cold-brick <brick>
> > ... <start|stop|status|commit|force>
> >
> > I have framed it this way because once we mention details about tiering
> > these commands become specific to tier and the syntax that we follow for
> > commands are gluster volume component <VOLNAME> ...
> > So i have made sure that the keyword tier comes after volume.
> > Need suggestions to make these commands better.
> >
> > Similarly once we support add/remove brick we will be having rebalance
> > commands and the idea is to support rebalance separately for each tier.
> > So once we will have to rebalance status to display for which we need
> > rebalance commands specific to tier. so these are the commands we have
> > thought of:
> > gluster v tier <VOLNAME> hot-rebalance/cold-rebalance <start|stop|status>
> >
> > Need your comments regarding this.
> >
> 
> Overall it makes sense. Just a comment here. Instead of mentioning
> remove/add/rebalance-hot/cold-brick can we have an additional arg called
> tier-type <hot/cold> and continue with the existing semantics like
> remove-brick, add-brick and rebalance?
> 
> 
> > --
> > Regards,
> > Hari.
> >
> > _______________________________________________
> > Gluster-devel mailing list
> > Gluster-devel at gluster.org
> > http://www.gluster.org/mailman/listinfo/gluster-devel
> >
> 
> 
> 
> --
> 
> --Atin
> 

-- 
Regards, 
Hari.