Local and Remote Membership and Caching

For many vFabric GemFire discussions, you need to understand the difference between local and remote membership and caching.

Discussions of GemFire membership and caching activities often differentiate between local and remote. Local caching always refers to the central member under discussion, if there is one such obvious member, and remote refers to other members. If there is no clear, single local member, the discussion assigns names to the members to differentiate. Operations, data, configuration, and so forth that are “local to member Q�? are running or resident inside the member Q process. Operations, data, configuration, and so on, that are “remote to member Q�? are running or resident inside some other member.

The local cache is the cache belonging to the local member. All other caches are remote, whether in other members of the same distributed system or in different distributed systems.

In the context of a single distributed system, unless otherwise specified, remote refers to other members of the same distributed system. In client/server and multi-site installations, remote generally refers to members in other distributed systems. For example, all servers are remote to the clients that connect to them. Each client runs standalone, with connections only to the server tier, so all servers and their other clients are remote to the individual client. All gateway hubs are remote to the gateways that connect to them from other distributed systems and to those gateways’ peers.