Pivotal GemFire® v8.1

Using Member Groups

Using Member Groups

Pivotal GemFire allows you to organize your distributed system members into logical member groups.

The use of member groups in Pivotal GemFire is optional. The benefit of using member groups is the ability to coordinate certain operations on members based on logical group membership. For example, by defining and using member groups you can:
  • Alter a subset of configuration properties for a specific member or members. See alter runtime in gfsh.
  • Perform certain disk operations like disk-store compaction across a member group. See Disk Store Commands for a list of commands.
  • Manage specific indexes or regions across all members of a group.
  • Start and stop multi-site (WAN) services such as gateway senders and gateway receivers across a member group.
  • Deploy or undeploy JAR applications on all members in a group.
  • Execute functions on all members of a specific group.

You define group names in the groups property of your member's file or upon member startup in gfsh.

Note: Any roles defined in the currently existing roles GemFire property will now be considered a group. If you wish to add membership roles to your distributed system, you should add them as member groups in the groups property. The roles property has been deprecated in favor of using the groups property.

To add a member to a group, add the name of a member group to the file of the member prior to startup or you can startup a member in gfsh and pass in the --group argument at startup time.

A single member can belong to more than one group.

Member groups can also be used to organize members from either a client's perspective or from a peer member's perspective. See Organizing Peers into Logical Member Groups and Organizing Servers Into Logical Member Groups for more information. On the client side, you can supply the member group name when configuring a client's connection pool. Use the <pool server-group> element in the client's cache.xml.