tomcat-dev mailing list archives

Site index · List index
Message view « Date » · « Thread »
Top « Date » · « Thread »
From Anthony Vromant <>
Subject Smooth applications migration in a J2EE cluster [mod_jk]
Date Tue, 05 Dec 2006 15:46:45 GMT

I am member of the JOnAS team (, the 
ObjectWeb application server (

We are developing a prototype which provides a smooth web applications 
migration mechanism within a Java EE cluster (without interruption of 
service and in a transparent way for the clients, i.e. without loss of 

The system of distribution of the client's requests towards the adequate 
version is actually based on a hook in mod_jk. During the update and 
when a new version of the application is deployed, the clients having 
started a session before the update are routed towards the cluster 
hosting the old version, whereas the new clients (news sessions) are 
routed towards the cluster hosting the new version of the application.

This prototype contains an administration API who provides 
functionalities to manage the update (jkupdater : begin update, end 
update, changed application version on a worker). The interface 
jkmanager has also been adapted in order to add information related to 
the migration.

We would be very interested to be able to exchange with you on this subject.
Feel free to give us your feedbacks. If you are interested, we can 
provide further informations and source code.

Would it be possible to integrate such a feature in the original mod_jk 
? If yes, we may contribute to the development by providing our code.

Anthony Vromant
Bull, Architect of an Open World TM

To unsubscribe, e-mail:
For additional commands, e-mail:

View raw message