The CometD Project

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

CometD Versions

CometD Version	Min Java Version	Min Jetty Version	Servlet APIs
8.0.x	Java 17	Jetty 12.0.x	EE10 jakarta.servlet.*
7.0.x	Java 11	Jetty 11.0.x	EE9 jakarta.servlet.*
6.0.x	Java 11	Jetty 10.0.x	EE8 javax.servlet.*
5.0.x	Java 8	Jetty 9.4.x	EE7 javax.servlet.*

CometD License

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

Project Directory Layout

cometd-archetypes    - The Maven archetypes for quick application development
cometd-demo          - Demo of the Java server and of the ES6/jQuery clients
cometd-documentation - The CometD documentation
cometd-java          - The Java server and java client libraries
cometd-javascript    - The JavaScript (ES6/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
cd $MY_SERVER
<command to run my server>

Reporting Issues

Issues, bugs and requests for enhancements should be filed at https://bugs.cometd.org

Building CometD

If you have cloned the source release, follow the instructions at https://docs.cometd.org/current/reference/#_build, or just do:

$ mvn install

CometD Benchmark

The CometD Benchmark can be run interactively or in batch mode.

To run the server interactively, open a terminal window and type:

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

Then follow the instructions printed in the terminal.

To run the client interactively, open another terminal window (potentially on another machine), and type:

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

Then follow instructions printed on the terminal to generate the load.