Terracotta Discussion Forums (LEGACY READ-ONLY ARCHIVE)

HI Taylor,

1) how do you balance between data center 1 and data center 2 load balancers? Are they A/P or A/A balanced?

We currently don't load balance between our two clusters. Currently we have one Primary Site, and other Secondary Site. The Primary Site is taking all the loads. But in case of the failure of Primary Site, the requests are being forwarded to the Secondary Site. Both primary and scendary sites have seperate load balancers within their clustered nodes.

2) After picking a load balancer (via the load balancing scheme in Q1), do your users return to the same load balancer? (I presume if yes, that the user will also return to the same node using sticky sessions - if no please explain)

Yes, they return to the same load balancer, but not necessarily to the same node. So, currently we don't use sticky sessions. Our users may go to any node within one cluster. That's one of the reason we are looking forward to implement Terracutta Sessions.

3) Where do you expect to share state? For example, would the 3 nodes in Data Center 1 share state with each other, but not the three nodes in Data Center 2? Or is it critical that if DC 1 is lost, users are able to transparently fail over to DC2 with no loss of session state?

We want the users to be able to transparently fail over to DC2 (Secondary Site), in case a failure of DC1 (Primary Site). We also want transparent fail over handling within nodes of a single session.

Please note that Primary Site, and Secondary Site are connected with each other using a seperate T1 connection.

For your convenience, I'm attaching a sample diagram of the configuration:

I'm looking forward to implement Tarracotta sessions over two clusters located in different locations. Each cluster has 3 nodes, seperate hardware load balancers, and the clusters are connected with a seperate T1 connection directly with each other. The latency beween a node of a cluster with another node of the other cluster is (average) 13ms.

So, what do you think about this scenario? How will Tarracotta Sessions perform in terms of Fail-Over of a single node? Will the performance be accaptable?

Thanks in advance...