[infinispan-dev] Use cases for x-datacenter replication

[Bela Ban]

Yes, this makes sense.

Although I doubt you will lose an entire data center. But an 
intermediate switch can always crash, making the DC inaccessible, which 
is the same problem for clients as if the entire DC crashed. Also, if we 
implement the follow-the-sun approach, then clients need to be switched 
over gracefully from one DC to another one, so this functionality 
definitely needs to be provided.

We probaby need to differentiate between a crash-failover and a graceful 
failover; in the latter case, clients can be switched over to the new DC 
within a certain time frame, so we minimize load spikes that might be 
caused by switching over all clients at exactly the same time.

I added your comment to 
https://community.jboss.org/wiki/CrossDatacenterReplication-Design, so 
we can discuss this next week (we have a meeting on cross-data center 
clustering WED-FRI in London).
Keep the suggestions coming !
Cheers,


On 2/15/12 7:02 PM, Erik Salter wrote:
> -- the clients reside on a separate network from the data centers.  So it is
> possible to lose a data center without losing the clients; they will simply
> route to another data center.
>
> In that case, there will be a notion of promotion of a data center as a
> primary key owner, which has its own set of implications (i.e. needs to be
> more local copies, etc).  And that means some sort of "fail back" once the
> original data center comes back online after any versioning merge occurs.
>

-- 
Bela Ban
Lead JGroups (http://www.jgroups.org)
JBoss / Red Hat