vFabric GemFire allows you to organize your distributed system
members into logical member groups.
The use of member groups in vFabric 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
gemfire.properties file.
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
gemfire.properties 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.