Tomcat request timeout

Question

In my web application there are some requests which last longer than 20 seconds. But in some situations the code can lead to infinite loop or something similar which slows down the server.

I want to put a request timeout for 60 sec on the server side. Is this implemented in tomcat ?

Thank you, Horatiu

Answer 1

With Tomcat 7, you can add the StuckThreadDetectionValve which will enable you to identify threads that are "stuck". You can set-up the valve in the Context element of the applications where you want to do detecting:

<Context ...>
  ...
  <Valve 
    className="org.apache.catalina.valves.StuckThreadDetectionValve"
    threshold="60" />
  ...
</Context>

This would write a WARN entry into the tomcat log for any thread that takes longer than 60 seconds, which would enable you to identify the applications and ban them because they are faulty.

Based on the source code you may be able to write your own valve that attempts to stop the thread, however this would have knock on effects on the thread pool and there is no reliable way of stopping a thread in Java without the cooperation of that thread...

Answer 2

If you are trying to prevent a request from running too long, then setting a timeout in Tomcat will not help you. As Chris says, you can set the global timeout value for Tomcat. But, from The Apache Tomcat Connector - Generic HowTo Timeouts, see the Reply Timeout section:

JK can also use a timeout on request replies. This timeout does not measure the full processing time of the response. Instead it controls, how much time between consecutive response packets is allowed.

In most cases, this is what one actually wants. Consider for example long running downloads. You would not be able to set an effective global reply timeout, because downloads could last for many minutes. Most applications though have limited processing time before starting to return the response. For those applications you could set an explicit reply timeout. Applications that do not harmonise with reply timeouts are batch type applications, data warehouse and reporting applications which are expected to observe long processing times.

If JK aborts waiting for a response, because a reply timeout fired, there is no way to stop processing on the backend. Although you free processing resources in your web server, the request will continue to run on the backend - without any way to send back a result once the reply timeout fired.

So Tomcat will detect that the servlet has not responded within the timeout and will send back a response to the user, but will not stop the thread running. I don't think you can achieve what you want to do.

Answer 3

You can set the default time out in the server.xml

<Connector URIEncoding="UTF-8" 
    acceptCount="100" 
    connectionTimeout="20000" 
    disableUploadTimeout="true" 
    enableLookups="false" 
    maxHttpHeaderSize="8192" 
    maxSpareThreads="75" 
    maxThreads="150" 
    minSpareThreads="25" 
    port="7777" 
    redirectPort="8443"/>

Answer 4

This article talks about setting the timeouts on the server level. http://www.coderanch.com/t/364207/Servlets/java/Servlet-Timeout-two-ways

What is causing the application to go into infinite loop? If you are opening connections to other resources, you might want to put timeouts on those connections and sending appropriate response when those time out occurs.

Answer 5

For anyone who doesn't like none of the solutions posted above like me then you can simply implement a timer yourself and stop the request execution by throwing a runtime exception. Something like below:

                  try 
                 {
                     timer.schedule(new TimerTask() {
                       @Override
                       public void run() {
                         timer.cancel();
                       }
                     }, /* specify time of the requst */ 1000);
                 }
                 catch(Exception e)
                 {
                   throw new RuntimeException("the request is taking longer than usual");
                 }

   

or preferably use the java guava timeLimiter here

Answer 6

Add tomcat in Eclipse

In Eclipse, as tomcat server, double click "Tomcat v7.0 Server at Localhost", Change the properties as shown in time out settings 45 to whatever sec you like