We noticed a significant drop in performance when running EJB client compared to EAP 7.0.

Short description of the testing scenario:

• many standalone EJB clients on three nodes spam a stateless bean (on fourth node) with requests (the number of threads on each node increases over time)
• the invoked method is just "echo", that means it returns the same value which was passed from client
• the value's size is 5 kB in "big data" scenario and 512 bytes in "small data" scenario
• the test ends when too many failures occur in clients (requests which fail with an exception)
• The perf test result is average duration of EJB calls

The numbers for big data scenario:

Good news, EAP 7.1 can handle more active clients.

The numbers for small data scenario:

What is notable is that with 7.0, the latencies increase quite steadily as the number of client increases, but with 7.1 they are very unpredictable, I saw cases where the latency reached 1000 ms with 2000 active clients and then dropped back to 200 ms after adding 1000 more clients...