Tomcat WebSockets issues and workaround - Atmosphere/atmosphere Wiki
The Tomcat WebSocket implementation is new and contains some issues. If you are using Atmosphere 1.0.0, make sure you read the following:
Connection gets closed after 20000 Workaround: Increase the value of connectionTimeout of the connector in server.xml Fixed in Tomcat 7.0.30 and up.
Sporadic NPE Workaround: No workaround, Atmosphere will handle the disconnection and recover from it)
ClassCastException with Spring Workaround: Upgrade Atmosphere 2.0.0