Do all cluster members need to be on the same local network? Yes. By default, the clustering module uses IP multicast to discover the cluster. This requires all cluster members to be on the same local network or for multicast traffic to be tunneled across multiple networks. See the Coherence documentation for more information.
Is it possible to have more than one cluster per physical network? Yes, this is possible. Coherence uses IP multicast to discover other cluster members. So, to isolate different clusters on the same physical network, you simply need to tell each cluster to use different multicast IPs or ports. The address and port can be specified with the appadd command (see Application Management Commands for more information).
Does searching work when clustering is enabled? Yes, searching works without needing to make any special configuration changes. Each cluster member will maintain its own search index and update it with the latest data (when auto-indexing is enabled).
Do gateways work with clustering? Yes, gateways will work transparently in a cluster.
How do config files work in a cluster? All configuration data (except bootstrap information such as database connection information) is stored in the database. Changing configuration settings on one cluster member will automatically update them on all other cluster members.
How do I set Coherence operational configuration parameters such as multicast port or address? The "instance" file contains the specific settings for each application. See the "appadd" documents for more information.
As a developer, how do I add a cache of my own? All caches are defined in the file WEB-INF/classes/coherence-cache-config.xml. The format of this file is defined and extensively documented by Oracle.