Following a few best practices will improve the performance and stability of your
clustered installation. Here are a few suggestions based general guidelines for the
clustering technology, as well as experience with Jive SBS in a clustered
environment.
- Use three nodes or more in your cluster. Two nodes will give you a redundancy
benefit, but is unlikely to help at all with performance (in fact, you might see
a performance decrease). If you're scaling for capacity, go from a single node
to three nodes.
- As a rule of thumb, consider going to a three-node cluster at approximately 12
million page views or 40 thousand users.
- Ensure that the number of nodes in your cluster is greater than what you'll need
to handle the load you're getting. For example, if you're at capacity with three
nodes, then the cluster will fail when one of those nodes goes down. Provision
excess capacity so that your deployment can tolerate a node's failure.
- When the application is deployed on a cluster, its heap size requirements will
decrease by as much as 50 percent or more. This is because the cluster
management software stores everything in serialized, rather than unserialized,
lists. With smaller heap size requirements, you can increase your cache sizes
(if you have a large database).
- Clustering tends to be very latency intolerant. To offset this, ensure that
everything is connected to a single gigabit switch and that all servers use
gigabit network cards.