include::../shared-doc/attributes.adoc[]

= servlet-async: How to Write an Asynchronous Servlet
:author: Christian Sadilek
:level: Intermediate
:technologies: Asynchronous Servlet, CDI, EJB

[abstract]
The `servlet-async` quickstart demonstrates how to use asynchronous servlets to detach long-running tasks and free up the request processing thread.

:standalone-server-type: default
:archiveType: war

//*************************************************
// Shared CD and Product Release content
//*************************************************

== What is it?

The `servlet-async` quickstart is a sample project showing the use of asynchronous servlets in {productNameFull}.

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.


//*************************************************
// Product Release content only
//*************************************************

ifndef::EAPCDRelease[]

// System Requirements
include::../shared-doc/system-requirements.adoc[leveloffset=+1]
// Use of {jbossHomeName}
include::../shared-doc/use-of-jboss-home-name.adoc[leveloffset=+1]
// Start the {productName} Standalone Server
include::../shared-doc/start-the-standalone-server.adoc[leveloffset=+1]
// Build and Deploy the Quickstart
include::../shared-doc/build-and-deploy-the-quickstart.adoc[leveloffset=+1]

== Access the Application

The application will be running at the following URL http://localhost:8080/{artifactId}/.

// Undeploy the Quickstart
include::../shared-doc/undeploy-the-quickstart.adoc[leveloffset=+1]
// Run the Quickstart in Red Hat JBoss Developer Studio or Eclipse
include::../shared-doc/run-the-quickstart-in-jboss-developer-studio.adoc[leveloffset=+1]
// Debug the Application
include::../shared-doc/debug-the-application.adoc[leveloffset=+1]

endif::[]

//*************************************************
// CD Release content only
//*************************************************

ifdef::EAPCDRelease[]

// Getting Started with OpenShift
include::../shared-doc/cd-openshift-getting-started.adoc[leveloffset=+1]
//Prepare OpenShift for Quickstart Deployment
include::../shared-doc/cd-create-project.adoc[leveloffset=+1]
// Import the Latest {xpaasproduct-shortname} Image Streams and Templates
include::../shared-doc/cd-import-imagestreams-templates.adoc[leveloffset=+1]
// Deploy the {ProductShortName} Source-to-Image (S2I) Quickstart to OpenShift
include::../shared-doc/cd-deploy-project.adoc[leveloffset=+1]
// OpenShift Post Deployment Tasks: This is not currently needed.
// include::../shared-doc/cd-post-deployment-tasks.adoc[leveloffset=+1]

endif::[]

