The CometD project, a scalable comet (server push) implementation for web messaging.
Java JavaScript Other

The CometD Project

Welcome to the CometD Project, a scalable comet (server push) implementation for the web.


The CometD source code is released under the Apache 2.0 License.

Directory Layout

cometd-archetypes - The Maven archetypes for quick application development
cometd-demo       - Demo of the Java server and of the Dojo/jQuery clients
cometd-java       - The Java server and java client libraries
cometd-javascript - The JavaScript (Dojo/jQuery) client libraries

Running the CometD Demo

If you have downloaded the release bundle, then the CometD is already built for you. To run the demonstration with Maven, unzip the release bundle and execute:

$ cd cometd-demo
$ mvn jetty:run

then point your browser at http://localhost:8080

Alternately you can deploy the CometD demo war file into any Servlet 2.5 or later server (e.g. jetty, tomcat, glassfish) with commands like:

$ cp cometd-demo/target/cometd-demo/target/cometd-demo-*.war  $MY_SERVER/webapps/cometd.war
<command to run my server>

Reporting Issues

Issues, bugs and requests for enhancements should be filed at

Building CometD

If you have cloned the source release, follow the instructions at, or just do:

$ mvn install

Load Testing CometD

To run load testing, open two windows. In the server window run:

$ cd cometd-java/cometd-java-benchmark/cometd-java-benchmark-server/
$ mvn exec:exec

In the client window (potentially on another machine), run

$ cd cometd-java/cometd-java-benchmark/cometd-java-benchmark-client/
$ mvn exec:exec

Then follow instructions on the console to generate load.