Has Java blocking IO on 64 bit Linux, in 2015, solved the C10K issue?
In other words:
Can a thread-per-socket Java server (not NIO), running on 64 bit Linux, keep 10,000 threads running?
Can it trivially reply to incoming data (on a small subset of the connections) within a millisecond or two?
I don't see any limitations inherent to Java here. Can you start 10,000 Java threads? Yes, easily. Can you open 10,000 java.io sockets? Yes, you can. Can your Linux setup handle it? The only way is to try and find out. Speaking from experience I saw JBoss servers do it on CentOS with >10k java.io connections.