Question

By default, the activemq uses tcp protocol. But now, I change it to use ssl.

If I deploy the publisher and server on one machine, it makes no difference with regard to the speed. But after I deploy them on different machine, it’s much slower to use ssl than to use tcp. Is this normal? If not, what’s probably wrong with my code?

Thanks.

Answer 1

Depends on how much slower your application is working.

If you process huge amount of data volumes, SSL will take a decent amount of CPU cycles to encrypt (and also decrypt) the data. Is it the ActiveMQ server that is slower or is it the client. Profile the system setup to get an overview where to find the bottenecks.

Another possibillity is frequent hand shakes. Say your client code (can you post it?) to send messages by opening a connection for each message, it might be the case that the latency for sending a message will suffer from the increased SSL handshake time compared to plain tcp.

UPDATE:

A speed up would be to reuse your connection. A SSL handshake has to be done for every message sent in your case which involves cpu expensive asymmetric crypto and a few more tcp roundtrips than plain TCP. It is easy to do, with the pooling connection factory provided by activemq. This example does not alter your code much:

public class MySender{
 private static ConnectionFactory factory = new org.apache.activemq.pool.PooledConnectionFactory("ssl://192.168.0.111:61616");
 public void send(){
  Connection connection = factory.createConnection();
  Session session = connection.createSession(false, Session.AUTO_ACKNOWLEDGE);
  Topic topic = session.createTopic(newDataEvent.getDataType().getType());
  MessageProducer producer = session.createProducer(topic);
  TextMessage message = session.createTextMessage();
  message.setText(xstream.toXML(newDataEvent));
  producer.send(message);
  session.close();
  connection.close(); 
 }
}