Custom Java Objects as Key in IgniteCache with persistence enabled

[Mitchell Rathbun (BLOOMBERG/ 731 LEX)]

I am attempting to use a custom Java class as a key in an IgniteCache instance 
with persistence enabled. I ran into some issues, so I made this class very 
simple for testing the problem. This class has an int member that is set to 1 
in the constructor, and then has equals overridden to return true, and hashcode 
overridden to return 1. I created a test that creates 100 different keys and 
writes each one to the cache. At the end I query the size of the cache. The 
first time I run this test with an empty cache, the size of the cache after 
writes is 1, which is what I would expect since all of the keys should be 
equal. However, when I run the test again, the size of the cache is 1 before 
the writes (which is expected), but 2 after the writes. Every time I run the 
test without clearing the cache will result in the cache size growing by 1. So 
key equality is not behaving as I would expect across runs. I do not have this 
issue when using String. How does Ignite define key equality if not by using 
equals/hashcode? Why would the same keys across runs not be treated as equal?