I think that patching these libraries might be a bit of a red herring though, in the sense that possibly the problem is way too much contention. The solution being more servers, less threads that take longer to process requests. It is so easy to let ExecutorService’s get out of control and assume that more threads == better.

For us I have a feeling that removing the charset contention is going to point to massive spikes in the number of threads we are using.