7.4.2.2. Configuring Interaction between Middleware Servers
Middleware servers can maintain shared lists of user sessions and other objects and coordinate invalidation of caches. cuba.cluster.enabled property should be enabled on each server to achieve this. Example of the tomcat/conf/app-core/local.app.properties
file is shown below:
cuba.cluster.enabled = true
cuba.webHostName = host3
cuba.webPort = 8080
cuba.webContextName = app-core
For the Middleware servers, correct values of the cuba.webHostName, cuba.webPort and cuba.webContextName properties should be specified to form a unique Server ID.
Interaction mechanism is based on JGroups. The platform provides two configuration files for JGroups:
-
jgroups.xml
- UDP-based stack of protocols which is suitable for local network with enabled broadcast communication. This configuration is used by default when the cluster is turned on. -
jgroups_tcp.xml
- TCP-based stack of protocols which is suitable for any network. It requires explicit setting of cluster members addresses inTCP.bind_addr
andTCPPING.initial_hosts
parameters. In order to use this configuration, set cuba.cluster.jgroupsConfig application property.
In order to set up JGroups parameters for your environment, copy the appropriate jgroups.xml
file from the root of cuba-core-<version>.jar
to your project core module or to tomcat/conf/app-core
and modify it.
ClusterManagerAPI
bean provides the program interface for interaction between servers in the Middleware cluster. It can be used in the application – see JavaDocs and usages in the platform code.