Hello Undertow Dev Team ,

      I have been working on the use case where i should create simple http server to serve 1.5 Million Requests per Second per Instance .. 

Here is the benchmark result of Undertow :

Running 1m test @ http://127.0.0.1:8009/

  20 threads and 40 connections

  Thread Stats   Avg      Stdev     Max   +/- Stdev

    Latency     2.51ms   10.75ms 282.22ms   99.28%

    Req/Sec     1.12k   316.65     1.96k    54.50%

  Latency Distribution

     50%    1.43ms

     75%    2.38ms

     90%    2.90ms

     99%   10.45ms

  1328133 requests in 1.00m, 167.19MB read

Requests/sec:  22127.92

Transfer/sec:      2.79MB

This is less compared to other frameworks like Jetty and Netty .. But originally Undertow is high performant http server .. 

Hardware details:

Xeon CPU E3-1270 v5 machine with 4 cores ( Clock 100 MHz, Capacity 4 GHz) , Memory : 32 G , Available memory 31 G.

I would need Undertow experts to review the server code below and advice me on tuning to achieve my goal( ~1.5 Million requests/sec ).

Server :

Undertow server = Undertow.builder()

               .addHttpListener(8009, "localhost")

               .setHandler(new Handler()).build();

server.start();

Handler.Java

    final Pooled<ByteBuffer> pooledByteBuffer =          

                 exchange.getConnection().getBufferPool().allocate();

final ByteBuffer byteBuffer = pooledByteBuffer.getResource();

   byteBuffer.clear();

   exchange.getRequestChannel().read(byteBuffer);

   int pos = byteBuffer.position();

   byteBuffer.rewind();

   byte[] bytes = new byte[pos];

   byteBuffer.get(bytes);

   String requestBody = new String(bytes, Charset.forName("UTF-8") );

   byteBuffer.clear();

   pooledByteBuffer.free();

   final PostToKafka post2Kafka = new PostToKafka();

try {

post2Kafka.write2Kafka(requestBody);  { This API can handle  ~2 Millions events per sec }

} catch (Exception e) {

e.printStackTrace();

}

    exchange.getResponseHeaders().put(Headers.CONTENT_TYPE, "text/plain");

    exchange.getResponseSender().send("SUCCESS");

--Senthil