What is the closest to ConcurrentHashMap and NavigableMap in Java?

[ilya-stromberg]

On Thursday, 14 November 2013 at 21:31:52 UTC, Jacek 
Furmankiewicz wrote:
> hashmap per thread is not an option. The cache may be a few GBs 
> of data, there is no way we can duplicate that data per thread.
>
> Not to mention the start up time when we have to warm up the 
> cache.

How often do you change the data? Probably, you should use 
`immutable` variables.