WildFly JGroups Subsystem Configuration
Internal
Relevance
- EAP 6.4
Subjects
Overview
The JGroups stacks are defined within the "jgroups" subsystem:
<subsystem xmlns="urn:jboss:domain:jgroups:1.1" default-stack="udp"> <stack name="udp"> <transport type="UDP" socket-binding="jgroups-udp"/> <protocol type="PING"/> <protocol type="MERGE3"/> <protocol type="FD_SOCK" socket-binding="jgroups-udp-fd"/> <protocol type="FD"/> <protocol type="VERIFY_SUSPECT"/> <protocol type="pbcast.NAKACK"/> <protocol type="UNICAST2"/> <protocol type="pbcast.STABLE"/> <protocol type="pbcast.GMS"/> <protocol type="UFC"/> <protocol type="MFC"/> <protocol type="FRAG2"/> <protocol type="RSVP"/> </stack> <stack name="tcp"> <transport type="TCP" socket-binding="jgroups-tcp"/> <protocol type="MPING" socket-binding="jgroups-mping"/> <protocol type="MERGE2"/> <protocol type="FD_SOCK" socket-binding="jgroups-tcp-fd"/> <protocol type="FD"/> <protocol type="VERIFY_SUSPECT"/> <protocol type="pbcast.NAKACK"/> <protocol type="UNICAST2"/> <protocol type="pbcast.STABLE"/> <protocol type="pbcast.GMS"/> <protocol type="UFC"/> <protocol type="MFC"/> <protocol type="FRAG2"/> <protocol type="RSVP"/> </stack> </subsystem>
Subsystem Configuration Schema
Default Values
JGroups stack configuration values are applied from, in this order:
1. standalone*.xml/domain.xml.
2. The ProtocolDefaultsService (implemented by org.jboss.as.clustering.jgroups.subsystem.ProtocolDefaultsService, part of jboss-as-clustering-jgroups-*.jar) which is initialized at startup with values from the file jgroups-defaults.xml embedded in the root of $JBOSS_HOME/modules/system/layers/base/org/jboss/as/clustering/jgroups/main/jboss-as-clustering-jgroups-*.jar or the respective overlay, if the installation was patched.
3. JGroups code defaults.
Configuring a New Protocol or Transport Attribute or Overriding Default Values
In case we need to override defaults or specify new properties at the transport level or at the protocol level, specify new sub-elements in <transport> and <protocol> as follows:
<subsystem xmlns="urn:jboss:domain:jgroups:1.1" ...> <stack name="udp"> <transport type="UDP" socket-binding="jgroups-udp"> <property name="thread_pool.max_threads">301</property> </transport> ... </stack> </subsystem>
<protocol type="PING"> <property name=”timeout”>20000</property> <protocol/>
A list of possible configuration attributes can be obtained from jgroups-defaults.xml embedded with $JBOSS_HOME/modules/system/layers/base/org/jboss/as/clustering/jgroups/main/jboss-as-clustering-jgroups-*.jar. A sample is provided here:
TCP-based Configuration
CLI Command to Configure TCPPING initial_hosts Value
TODO: relocate.
/subsystem=jgroups/stack=tcp/protocol=TCPPING/property=initial_hosts:write-attribute(name="value", value="node1[7600], node2[7600],node3[7600]") reload