WildFly JGroups Subsystem Configuration

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• WildFly JGroups Subsystem

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• EAP 6.4

Subjects

• WildFly Clustering without Multicast

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

WildFly Configuration Schemas

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:

jgroups-defaults.xml

TCP-based Configuration

WildFly Clustering without Multicast