Master node election process may result in multiple master nodes if the nodes lose connectivity during election

• Type: Bug
• Status: Closed
• Resolution: Duplicate
• Affects Version/s: 6.2.X EE, 7.0.0 Beta 4
• Fix Version/s: 6.2.X EE, 7.0.0 Alpha 4
• Component/s: Fault Tolerance, Fault Tolerance > Clustering Framework
• Labels: None
• Fix Priority: 4

running these two scripts might demonstrate an inconsistency between the in memory "isMaster" and the lock table

import com.liferay.portal.kernel.cluster.ClusterExecutorUtil;
import com.liferay.portal.service.LockLocalServiceUtil;

import com.liferay.portal.kernel.cluster.Address;
import com.liferay.portal.model.Lock;
import com.liferay.portal.kernel.util.Validator;

try {
 	String _LOCK_CLASS_NAME = "com.liferay.portal.cluster.ClusterMasterExecutorImpl";

	String localAddress = AddressSerializerUtil.serialize(
		ClusterExecutorUtil.getLocalClusterNodeAddress());

	String masterAddress = null;

	for (int i = 0; i < 10; i++) {
		try {
			Lock lock = null;

			if (masterAddress == null) {
				lock = LockLocalServiceUtil.lock(
					_LOCK_CLASS_NAME, _LOCK_CLASS_NAME,
					localAddress);
			}
			else {
				lock = LockLocalServiceUtil.lock(
					_LOCK_CLASS_NAME, _LOCK_CLASS_NAME, masterAddress,
					localAddress);
			}

			masterAddress = lock.getOwner();

			Address address = AddressSerializerUtil.deserialize(masterAddress);

			if (ClusterExecutorUtil.isClusterNodeAlive(address)) {
				out.println("master is alive");

				break;
			}
			else {
				out.println("master is not alive");
			}
		}
		catch (Exception e) {
			out.println("Master Address: " + masterAddress);
			out.println("Unable to acquire memory scheduler cluster lock" + e.getMessage());
		}
	}

	out.println("Local Address:" +  AddressSerializerUtil.deserialize(localAddress));
	out.println("Master Address: " +  AddressSerializerUtil.deserialize(masterAddress));
}
catch (Exception e) {
	e.printStackTrace();

	out.println(e.getMessage());
}

out.println(com.liferay.portal.kernel.cluster.ClusterMasterExecutorUtil.isMaster());

this can occur if the cluster temporarily loses connectivity during the master election process because a node only attempts to connect once before nominating itself as the master node.