Re: [Gluster-devel] Glusterd: A New Hope

[Joe Julian]

Anand Babu Periasamy <address@hidden> wrote:

>On Tue, Mar 26, 2013 at 5:59 AM, Jeff Darcy <address@hidden> wrote:
>> On 03/25/2013 11:59 PM, Anand Babu Periasamy wrote:
>>> gluster meta-volume + zeromq for notification (pub/sub) will solve
>our
>>> problems largely and still be light weight.  In a large scale
>>> deployment, it is not a good idea to declare all the servers as
>>> coordination servers. Since meta-volume is a regular distributed
>>> replicated gluster volume, it can always be expanded later depending
>>> on the load and availability requirements.
>>
>> How do you propose to solve the bootstrap problem?  How do we choose
>> which subset of all servers would have pieces of this meta-volume?
>> How do we coordinate its expansion, or detect and respond to failures
>of
>> itscomponents?
>
>Admin declares the config servers manually. Automatic option is a
>disaster waiting to happen.
>
>We should set the minimum number of config servers required by default
>to 3, so that we can enforce quorum. Any failure would require the
>admin to declare replacement config servers manually.

On that note, the additional quorum functionality should be implemented with 
regard to watchers before using a glusterfs store for configuration 
coordination.

>From what I've been reading, the biggest thing zookeeper has over any other 
>solution is its robustness with regard to split-brain. If that was managed it 
>seems like that would open up a number of possibilities to satisfy the other 
>requirements.