[Gluster-devel] Update on better peer identification

[Kaushal M]

Hi everyone,

As everyone hopefully knows by now, improving the peer identification
mechanism within Glusterd is one of the features being targeted for
glusterfs-3.6. [0]

I had proposed this a while back, but had not been able to do much
work related to this till now. Varun (CCd) and I have been working on
this since last week, and are hoping to get at least the base
framework ready and merged into 3.6.

The main problem we have currently is that a peer can be associated
with just a single address. This is stored in peerinfo->hostname. This
isn't sufficient to address all possible addresses a peer could be
associated with and lead to failures identifying peers during various
commands. Also our identification isn't able to correctly match
shortname, fqdns and ips, which could also lead to failures.

Varun and me are hoping to solve these two problems and are currently
working towards it. We hope to do the following,
1. Extend peerinfo to hold a list of addresses instead of a single address.
2. Improve peer probe to add unknown addresses to this list when we
identify that it belongs to a known peer
3. Improve glusterd_friend_by_hostname helper to correctly handle
matching addresses.

These 3 changes should lay down the base for improving glusterds peer
identification problems.

I've updated the feature page [0] with the latest details.

We have been doing changes over the past week, and our changes can be
viewed on my glusterfs forks on forge [1] and github [2].

We currently don't have any changeset for review on gerrit, but if
anyone wants to review code right now, you can use [3].

Thanks.

~kaushal

[0] - http://www.gluster.org/community/documentation/index.php/Features/Better_peer_identification
[1] - https://forge.gluster.org/~kshlm/glusterfs-core/kshlms-glusterfs/commits/better-peer-identification
[2] - https://github.com/kshlm/glusterfs/tree/better-peer-identification
[3] - https://github.com/kshlm/glusterfs/pull/2/files