Enforce the convertion between URI and String.
Use the PUB_URI for setting the Hazelcast IP address.
This issue also gives the code (commented) for solving the issue #54.
This code is commented because it needs a bug fix in Hazelcast.
When the kernel discovery service is stopped, the kernel is removed from the shared set of kernel IDs (issue #56).
Upgrade Hazelcast to 3.3-EA