[infinispan-dev] design for cluster events (wiki page)

[Dennis Reed]

On 10/31/2013 02:18 AM, Bela Ban wrote:
>
>> Also if we did have read only, what criteria would cause those nodes
>> to be writeable again?
> Once you become the primary partition, e.g. when a view is received
> where view.size() >= N where N is a predefined threshold. Can be
> different, as long as it is deterministic.
>
>> There is no guarantee when the other nodes
>> will ever come back up or if there will ever be additional ones anytime soon.
> If a system picks the Primary Partition approach, then it can become
> completely inaccessible (read-only). In this case, I envisage that a
> sysadmin will be notified, who can then start additional nodes for the
> system to acquire primary partition and become accessible again.

There should be a way to manually modify the primary partition status.
So if the admin knows the nodes will never return, they can manually 
enable the partition.

Also, the PartitionContext should know whether the nodes left normally 
or not.
If you have 5 nodes in a cluster, and you shut down 3 of them, you'll 
want the remaining two to remain available.
But if there was a network partition, you wouldn't.  So it needs to know 
the difference.

-Dennis