While debuging I see that httpUpgradeHandlerClass in upgrade of org.apache.catalina.connector.Request is class org.apache.tomcat.websocket.server.WsHttpUpgradeHandler
InstanceManager is org.apache.catalina.core.DefaultInstanceManager in the source code of my maven dependency of tomcat-api-7.0.47 this method should exist: public interface InstanceManager { public Object newInstance(Class<?> clazz) throws IllegalAccessException, InvocationTargetException, NamingException, InstantiationException; ... Any clue ?