We need to document some of the "maximum" sizes allowed by Infinispan:

• maximum cache entry size (key and value) for heap and off-heap.
• limitations on persistence (e.g. JDBC BLOBs)
• maximum REST payload
• usage of streaming APIs to deal with large objects (HTTP/1.1 chunked transfer encoding or HTTP/2)
   

From google chat conversation:
Are there any limits to the size of data/objects that can be stored in a cache entry?
For example, is a binary object (blob) an appropriate value for a key in a cache? 2 GB
the server has the 2GB limitation

Will Rosenquist Burns, Yesterday 6:38 PM
That limit is intrinsic to us as we use byte[] for messages and that is limited to 2^31. Note the 2GB consists of the key and value size and some internal metadata, so for a single value it is a bit less than 2GB.

I wouldn't recommend 2 GB in a single value though, especially if this is a distributed cache as you will lose a lot of value of having keys automatically written to different nodes if only a few values will fill up your heap

Will Rosenquist Burns, Yesterday 6:40 PM, Edited
And if the keys are not balanced equally you will have some nodes running out of memory a lot quicker than others