[Gluster-devel] Support for Scaling TIered volume, ie Add/Remove brick and Rebalance

[Mohammed Rafi K C]

Hi,

The current implementation of Tiering lacks support for rebalance, as
the migration daemon uses the framework for rebalance process. Because
of this constraints, we were forced to remove support for add/remove
brick on a tired volume.

We are now focusing to bring rebalance support along with add/remove
brick. Steps involved in the overall process would be ,

1) Tier process as a service based daemon
2) Changes to current add/remove brick cli to specify the tier which we
want to scale.
3) Changes to rebalance cli to start rebalance on tiers
4) glusterd support for add/remove brick operation on tiering.
5) Changes to rebalance status.
6) Addressing Backward compatibility.

Before starting, we want to get your expert opinions on this topics. I
have created a doc [1] file that contains some of the question that
stuck in mind. It would be great if you guys can provide your thoughts
as a comment on the Doc file.

[1] https://goo.gl/ODO5Pc

Thanks in Advance.

Regards
Rafi KC