okhttp Dispatcher throws executor rejected

Question

I am using Okhttp Dispatcher in my application to send out HTTP2 request to a simulator which is an Reactor Netty HTTPSever . Actually we are doing a PT with 10 simulators , out of which 9 simulators have a delay of 50 ms , things work fine in this case , but when i introduce the 10th simulator with 10 seconds delay then immediately all of the requests are failing with executor rejected error response. Below is the dispatcher configuration used

Dispatcher dispatcher = new Dispatcher(new ThreadPoolExecutor( 1, 350, 60L, TimeUnit.SECONDS, new SynchronousQueue(), Util.threadFactory(HTTP_THREAD_NAME_DEFAULT, false)));

        dispatcher.setMaxRequestsPerHost(300);
        dispatcher.setMaxRequests(500);

I have tried increasing the ThreadPoolExecutor max threads to 500 , MaxRequestsPerHost to 500 and MaxRequests to 800, but things don't work

NOTE: we are testing with 4k tps and its an springboot application not mobile application

Answer 1

OkHttp uses the parameters maxRequests and maxRequestsPerHost to determine concurrency. You should keep the default dispatcher and use these tuning parameters instead.