Unable to load protocol class org.jgroups.protocols.openshift.DNS_PING when using customized standalone-openshift.xml

Environment

• Red Hat JBoss Enterprise Application Platform (EAP)
  • 7.x image
• Red hat OpenShift Container Platform (OCP)
  • 4/3

Issue

• When using customized standalone-openshift.xml with openshift.DNS_PING, the following error occurred on startup container.

<protocol type="openshift.DNS_PING" socket-binding="jgroups-mping"/>

ERROR [org.jboss.as.controller.management-operation] (ServerService Thread Pool -- 24) WFLYCTL0013: Operation ("add") failed - address: ([
    ("subsystem" => "jgroups"),
    ("channel" => "ee")
]) - failure description: "WFLYCLJG0016: Unable to load protocol class org.jgroups.protocols.openshift.DNS_PING"

Resolution

For enabling/disabling clustering capabilities, see solution EAP 7 image clustering in OCP 4.

Remove the line of the protocol customized as openshift.DNS_PING in your customized standalone-openshift.xml.

<protocol type="openshift.DNS_PING" socket-binding="jgroups-mping"/>

And make sure an environment variables JGROUPS_PING_PROTOCOL in deployment config set dns.DNS_PING as a value.
Then the ping would be set properly as follows when starting up the container.

<protocol type="dns.DNS_PING">
    <property name="dns_query">hello-ping</property>
    <property name="async_discovery_use_separate_thread_per_request">true</property>
</protocol>

Root Cause

In EAP 7.3 documentation, the openshift.DNS_PING has been described but it is stale. Correct protocol is dns.DNS_PING. That is filed as doc bug This content is not included.JBEAP-16038.
openshift.DNS_PING is deprecated from EAP 7.2 for openshift. EAP 7.3 can not load the deprecated classes and will throw error.

openshift.DNS_PING was deprecated in EAP 7.2 and removed in EAP 7.3, meaning if one specifies openshift.DNS_PING in the config, it will not work (break as parsing) and must be updated to dns.DNS_PING.

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