The VMware GemFire cluster configuration service persists cluster configurations created by
gfsh commands to the locators in a cluster and distributes the configurations to members of the cluster.
We highly recommend that you use the
gfsh command line and the cluster configuration service as the primary mechanism to manage your cluster configuration. Specify configuration within a
cache.xml file for only those items that cannot be specified or altered using
gfsh. Using a common cluster configuration reduces the amount of time you spend configuring individual members and enforces consistent configurations when bringing up new members in your cluster. You no longer need to reconfigure each new member that you add to the cluster. You no longer need to worry about validating your
cache.xml file. It also becomes easier to propagate configuration changes across your cluster and deploy your configuration changes to different environments.
You can use the cluster configuration service to:
To use the cluster configuration service in GemFire, you must use dedicated, standalone locators in your deployment. You cannot use the cluster configuration service with co-located locators (locators running in another process such as a server).
The standalone locators distribute configuration to all locators in a cluster. Every locator in the cluster with
--enable-cluster-configuration set to true keeps a record of all cluster-level and group-level configuration settings.
Note: The default behavior for
gfsh is to create and save cluster configurations. You can deactivate the cluster configuration service by using the
--enable-cluster-configuration=false option when starting locators.
You can load existing configuration into the cluster by using the
gfsh import cluster-configuration command after starting up a locator.
Subsequently, any servers that you start with
gfsh that have
--use-cluster-configuration set to
true will pick up the cluster configuration from the locator as well as any appropriate group-level configurations (for member groups they belong to). To deactivate the cluster configuration service on a server, you must start the server with the
--use-cluster-configuration parameter set to
false. By default, the parameter is set to true.
When you use
gfsh commands to create VMware GemFire regions, disk-stores, and other objects, the cluster configuration service saves the configurations on each locator in the cluster. If you specify a group when issuing these commands, a separate configuration is saved containing only configurations that apply to the group.
When you use
gfsh to start new VMware GemFire servers, the locator distributes the persisted configurations to the new server. If you specify a group when starting the server, the server receives the group-level configuration in addition to the cluster-level configuration. Group-level configurations are applied after cluster-wide configurations; therefore you can use group-level to override cluster-level settings.
Developer or Administrator executes
gfsh commands to configure the cluster.
gfsh saves the cluster information on the locators. Existing servers using cluster configuration are configured.
Developer or Administrator executes
gfsh to add new members to the cluster.
New members request the configuration from a locator.
Locator distributes the configuration to new servers joining the cluster. Configuration includes regions, disk stores, and jar files,
gfsh commands cause the configuration to be written to all locators in the cluster (the locators write the configuration to disk):
* Note that the
configure pdx command must be executed before starting your data members. This command does not affect any currently running members in the system. Data members (with cluster configuration enabled) that are started after running this command will pick up the new PDX configuration.
** If cluster configuration is enabled, the region this command is applied to must exist in the cluster configuration. If that is not the case, the command will fail saying the region does not exist.
These are the configurations that you cannot create or alter using
gfsh. These configurations must be within a
cache.xml file or be applied by using the API:
You cannot directly modify the attributes of the following objects:
configure pdx command always specifies the
org.apache.geode.pdx.ReflectionBasedAutoSerializer class. You cannot specify a custom PDX serializer in gfsh.
If you do not want to use the cluster configuration service, start up your locator with the
--enable-cluster-configuration parameter set to false or do not use standalone locators. You will then need to configure the cache (via cache.xml or API) separately on all your cluster members.