ISPN-4424 Synchronize updating cache entry and making a copy
ISPN-4424 Synchronize updating cache entry and making a copy
- making the CacheEntry immutable is not enough, the whole CacheEntry hierarchy needs to be made immutable
- using clone is simpler that making the hierarchy immutable
ISPN-1951 Use MERGE3 in the default UDP configuration

TEST_PING needed some changes, as MERGE3 doesn't trigger Discovery.findMembers()
Smaller timer pool and queue.
Still causes lots of failures.