This issue has popped up a couple of times for me recently, so I thought I would do a quick post on it.
When you are running a number of Fusion Middleware environments in the same IP subnet, as you might be in a test environment for example, the default Coherence startup parameters can cause you some issues.
A quick and easy way to avoid these issues, is to change the Coherence clusterport setting, and add the Coherence ttl setting, as shown in the example below. You can do this by updating the EXTRA_JAVA_PROPERTIES variable in the setDomainEnv.sh script inside your domain’s bin directory.
EXTRA_JAVA_PROPERTIES="${EXTRA_JAVA_PROPERTIES} -Dsoa.archives.dir=${SOA_ORACLE_HOME}/soa -Dsoa.oracle.home=${SOA_ORACLE_HOME} -Dsoa.instance.home=${DOMAIN_HOME} -Djava.net.preferIPv4Stack=true -Dweblogic.security.SSL.ignoreHostnameVerification=true -Dhttp.nonProxyHosts=localhost|10.240.37.80|slc01ats|*.oracle.com -Dtangosol.coherence.clusteraddress=227.7.7.9 -Dtangosol.coherence.clusterport=9838 -Dtangosol.coherence.ttl=0 -Dtangosol.coherence.log=jdk -Djavax.xml.soap.MessageFactory=oracle.j2ee.ws.saaj.soap.MessageFactoryImpl -Dweblogic.transaction.blocking.commit=true -Dweblogic.transaction.blocking.rollback=true -Djavax.net.ssl.trustStore=${WL_HOME}/server/lib/DemoTrust.jks" export EXTRA_JAVA_PROPERTIES
Ideally, you want to set tangosol.coherence.clusterport to a different value for each separate cluster. Set tangosol.coherence.ttl to 0 as shown above.