> From: Marvin Addison > Sent: Monday, July 13, 2015 6:42 AM > > I'd be curious to know why you don't like it. I encourage you to discuss > further > on shib-users.
To be honest, I haven't really reviewed the memcached clustering implementation for the idp, my opinion is based on looking at the CAS memcached implementation, but I believe it is based on underlying memcached characteristics, not CAS specific implementation details, so is still valid. The primary reason I did not like the memcached implementation was that it is not truly fault-tolerant. As I understand it, any given key is hashed and stored on one of the available memcached nodes. A client that needs it performs the same hash, and tries to retrieve it from the same node. I have a three node CAS cluster. With the memcached ticket registry, if one of the nodes were to crash, I would simply lose a third of my state. On the other hand, with the hazelcast ticket registry backend, a backup copy of the state on any given node is available on another node, and if you lose only a single node, you lose no state. Given my goal was to deploy a cluster not simply for load-balancing, but also for high-availability and fault tolerance, choosing a ticket registry backend that did not supply the latter was a no go. > would be met by a single platform and it became a straightforward economic > decision: consolidate and save. Of course our needs and yours are likely > different; you'll have to evaluate for yourself whether a single platform > meets > your requirements. Thanks for the info. Barring the availability of an idp clustering backend more like Hazelcast in terms of fault tolerance (perhaps somebody at Unicon might be interested in putting one together :)? ) I think I'm leaning towards keeping them separate with the cluster state on the CAS side for now. Thanks much for the information… -- You are currently subscribed to [email protected] as: [email protected] To unsubscribe, change settings or access archives, see http://www.ja-sig.org/wiki/display/JSG/cas-user
