We need to setup below properties in our portal-ext.properties(this is for ONE INSTANCE represented by 1p, same properties we need to add for second instance also represented by 2p) and some required IP addresses.

#cluster configurations - these SETTINGS are for cluster
net.sf.ehcache.configurationResourceName=/myehcache/hibernate-clustered.xml
dl.store.file.system.root.dir=/webapps/document_library_cluster
#other settings for cluster
liferay.home=/webapps/liferay-1p/liferay-portal-6.1.10-ee-ga1/
lucene.dir=/webapps/liferay-1p/liferay-portal-6.1.10-ee-ga1/data/lucene
cluster.link.enabled=true
lucene.replicate.write=true
multicast.group.address["cluster-link-control"]=239.255.4.1

We need to setup below properties in our portal-ext.properties(this is for one instance represented by 1p, same properties we need to add for second instance also represented by 2p) and some required IP addresses.

#cluster configurations - these settings are for cluster
net.sf.ehcache.configurationResourceName=/myehcache/hibernate-clustered.xml
dl.store.file.system.root.dir=/webapps/document_library_cluster
#other settings for cluster
liferay.home=/webapps/liferay-1p/liferay-portal-6.1.10-ee-ga1/
lucene.dir=/webapps/liferay-1p/liferay-portal-6.1.10-ee-ga1/data/lucene
cluster.link.enabled=true
lucene.replicate.write=true
multicast.group.address["cluster-link-control"]=239.255.4.1