What is the compatibility between versions of Hazelcast clients and servers?
Starting with Hazelcast 3.6, Hazelcast server & client versions are backward and forward compatible within the same major version. For example, 3.8 clients can work with 3.7 servers. However, if you have mismatched versions, features introduced at the newer version will not be available if dependent upon functionality not present in the older version.
For further information, see: https://hazelcast.org/clients-languages/compatibility-matrix/