You may see the following exceptions in any Hazelcast operation when the described situations occur:
- 
HazelcastInstanceNotActiveException: Thrown whenHazelcastInstanceis not active (already shutdown or being shutdown) during an invocation.
- 
HazelcastOverloadException: Thrown when the system cannot handle any more load due to an overload. This exception is thrown when back pressure is enabled.
- 
DistributedObjectDestroyedException: Thrown when a distributed data structure is destroyed using thedestroy()method while there is a blocking operation on it, e.g., waiting a response for theLock.lock()method.
- 
MemberLeftException: Thrown when a member leaves during an invocation or execution.
Hazelcast also throws the following exceptions in the cases of overall system problems such as networking issues and long pauses:
- 
PartitionMigratingException: Thrown when an operation is executed on a partition, but that partition is currently being moved.
- 
TargetNotMemberException: Thrown when an operation is sent to a machine that is not a member of the cluster.
- 
CallerNotMemberException: Thrown when an operation was sent by a machine which is not a member in the cluster when the operation is executed.
- 
WrongTargetException: Thrown when an operation is executed on the wrong machine, usually because the partition that operation belongs to has been moved to some other member.