Author: Christian Sadilek
Level: Intermediate
Technologies: Asynchronous Servlet, CDI, EJB
Summary: The servlet-async
quickstart demonstrates how to use asynchronous servlets to detach long-running tasks and free up the request processing thread.
Target Product: WildFly
Source: https://github.com/wildfly/quickstart/
The servlet-async
quickstart is a sample project showing the use of asynchronous servlets in WildFly Application Server.
It shows how to detach the execution of a long-running task from the request processing thread, so the thread is free to serve other client requests. The long-running tasks are executed using a dedicated thread pool and create the client response asynchronously.
A long-running task in this context does not refer to a computation intensive task executed on the same machine but could for example be contacting a third-party service that has limited resources or only allows for a limited number of concurrent connections. Moving the calls to this service into a separate and smaller sized thread pool ensures that less threads will be busy interacting with the long-running service and that more requests can be served that do not depend on this service.
The application this project produces is designed to be run on WildFly Application Server 11 or later.
All you need to build this project is Java 8.0 (Java SDK 1.8) or later and Maven 3.3.1 or later. See Configure Maven for WildFly 11 to make sure you are configured correctly for testing the quickstarts.
In the following instructions, replace WILDFLY_HOME
with the actual path to your WildFly installation. The installation path is described in detail here: Use of WILDFLY_HOME and JBOSS_HOME Variables.
For Linux: WILDFLY_HOME/bin/standalone.sh
For Windows: WILDFLY_HOME\bin\standalone.bat
mvn clean install wildfly:deploy
This will deploy target/servlet-async.war
to the running instance of the server.
The application will be running at the following URL http://localhost:8080/servlet-async/.
mvn wildfly:undeploy
You can also start the server and deploy the quickstarts or run the Arquillian tests from Eclipse using JBoss tools. For general information about how to import a quickstart, add a WildFly server, and build and deploy a quickstart, see Use JBoss Developer Studio or Eclipse to Run the Quickstarts.
If you want to debug the source code of any library in the project, run the following command to pull the source into your local repository. The IDE should then detect it.
mvn dependency:sources