Distributed system members are programs that
connect to a Pivotal GemFire distributed system. You configure members to belong to a single
distributed system, and you can optionally configure them to be clients or servers to
members in other distributed systems, and to communicate with other distributed systems.
Distributed system members (or simply "members") connect to the GemFire system when they
create the GemFire data cache. The members' distributed system is configured through
GemFire properties. See gemfire.properties and gfsecurity.properties (GemFire Properties).
GemFire properties specify all necessary information for system member startup,
initialization, and communication.
Note: You cannot change a member's properties while the member is connected to the
Use the properties to define:
- How to find and communicate with
other system members
- How to perform logging and
- Licensing information for the
- What cache.xml
file to use for cache and data region initialization
- Other options, including event
conflation, how to handle network loss, and security settings
Distributed System Membership and System Topologies
Every GemFire process is a member of a distributed system, even if the distributed system is
defined as standalone, with just one member. You can run an individual distributed
system in isolation or you can combine systems for vertical and horizontal scaling.
See Topology and Communication General Concepts
- Peer-to-Peer Distributed
Systems. Members that define the same member discovery properties
belong to the same distributed system and are peers to one another.
- Client/Server Installations.
The client/server topology uses relationships that you configure between
members of multiple distributed systems. You configure some or all of the
peers in one distributed system to act as cache servers to clients
connecting from outside the system. Each server can host many client
processes, managing cache access for all in an efficient, vertically
hierarchical cache configuration. You configure the client applications to
connect to the servers, using a client cache configuration. Clients run as
members of standalone GemFire distributed systems, with no peers, so all
data updates and requests go to the servers.
- Multi-site Installations.
The multi-site topology uses relationships that you configure between
members of multiple distributed systems. Through this configuration, you
loosely couple two or more distributed systems for automated data
distribution. This is usually done for sites at geographically separate
locations. You configure a subset of peers in each distributed system site
with gateway senders and/or gateway receivers to manage events that are
distributed between the sites.