Warning that "unknown addresses are found in partition table" <p>When using Hazelcast, I get warnings like:</p> <pre><code>Jun 21, 2015 11:10:15 AM com.hazelcast.partition.InternalPartitionService WARNING: [192.168.0.18]:5701 [5a11] [3.4.2] Following unknown addresses are found\ in partition table sent from master[Address[192.168.0.9]:5701]. (Probably they have recently joined or left the cluster.) { Address[192.168.0.13]:5701 } Jun 21, 2015 11:10:29 AM com.hazelcast.partition.InternalPartitionService WARNING: [192.168.0.18]:5701 [5a11] [3.4.2] Following unknown addresses are found\ in partition table sent from master[Address[192.168.0.20]:5701]. (Probably they have recently joined or left the cluster.) { Address[192.168.0.11]:5701 Address[192.168.0.17]:5701 } Warning: irregular exit, check log </code></pre> <p>What is the cause, and do I have to take actions to avoid these warnings?</p> <hr> <p>Details:</p> <p>These warning occur at the end of my distributed computations, and not for all instances. So it is very likely that some other instances have terminated and thus "recently left the cluster" when this warning occurs. </p> <p>But why does an instance leaving cause an unknown address? Does this mean the instance <code>x</code> giving the warning somehow found out that instance <code>y</code> has left, and the master hasn't yet found out and sends the address of <code>y</code> to <code>x</code>, causing this warning?</p> <p>Should I take actions to avoid this warning? Does it mean that <code>y</code> forgets some cleanup it is supposed to do at the end so that the master immediately finds out that <code>y</code> leaves the cluster? The only cleanup the instances are performing is <code>shutdown()</code> of their <code>HazelcastInstance</code>.</p> <p>Is the irregular exit at the end of my log messages caused by the inconsistency in the partition table?</p>