Bugs item #871649, was opened at 2004-01-06 13:16 Message generated for change (Comment added) made by ejort You can respond by visiting: https://sourceforge.net/tracker/?func=detail&atid=376685&aid=871649&group_id=22866
Category: JBossMX Group: v3.2 Status: Open >Resolution: Accepted Priority: 5 Submitted By: Jeff Haynie (jhaynie) >Assigned to: Jeff Haynie (jhaynie) Summary: Problem with source of JMX Notifications Initial Comment: According to the JMX spec, the source of a Notification must be of type ObjectName. At line 420 in ServerImpl: Notification msg = new Notification (START_NOTIFICATION_TYPE, this, 1); should be changed to: Notification msg = new Notification (START_NOTIFICATION_TYPE, ServerImplMBean.OBJECT_NAME, 1); We should also update JMX to check this (although I thought it did before - maybe its happening at the at a higher level in the BasicMBeanRegistry). The problem is that the ListenerRegistration in the NotificationBroadcasterSupport.sendNotification() will evaluate the NotificationFilter before being dispatched up to the listener. The listener is being wrapped at a higher level by the mbean server using the NotificationListenerProxy which sets the source - but this happens after the filter is applied -- which causes problems if you're checking the ObjectName in the filter. An easy enough fix for this particular problem is just to do above. However, I'm worried we'll still see this in other places. Another thought is to wrap the MBeanServerListenerRegistration (which creates NotificationListenerProxy) and pass in a proxy to the filter, such that it will set the appropriate source using the MBeanServerListenerRegistration and then delegate to the appropriate filter. The other thing is to enforce in our Notification implementation ObjectName in setSource and the constructor -- which according to the JMX spec we're suppose to throw an IllegalArgumentException. ---------------------------------------------------------------------- >Comment By: Adrian Brock (ejort) Date: 2004-01-06 13:50 Message: Logged In: YES user_id=9459 Yes, go ahead. Regards, Adrian ---------------------------------------------------------------------- Comment By: Jeff Haynie (jhaynie) Date: 2004-01-06 13:44 Message: Logged In: YES user_id=4529 OK, looking at the JMX 1.2 spec javadoc for Notification, it states: "The Notification class represents a notification emitted by an MBean. It contains a reference to the source MBean: if the notification has been forwarded through the MBean server, this is the object name of the MBean. If the listener has registered directly with the MBean, this is either the object name or a direct reference to the MBean. It is strongly recommended that notification senders use the object name rather than a reference to the MBean object as the source." In my case, and in the case for jboss mx, we're not registering directly with the mbean. I like the idea of filter proxy since it would enforce the ObjectName externally and still allow either ObjectName or direct reference in the implementation of an MBean. Is this something you would like me to apply? ---------------------------------------------------------------------- Comment By: Adrian Brock (ejort) Date: 2004-01-06 13:34 Message: Logged In: YES user_id=9459 The only requirement from the spec is that notification listeners registered through the MBeanServer receive notifications with the ObjectName they registered against. Direct notifications (i.e. where you register directly with the MBean) are not required to use the ObjectName, but direct notifications are frowned upon. You cannot setSource() a normal object but there is no such requirement on the constructor. Unless the broadcaster also implements MBeanRegistration it does not know its own ObjectName. One way to fix the problem would be to add a NotificationFilterProxy that replaces the source with the ObjectName in the same way that is done for the NotificationListener. Regards, Adrian ---------------------------------------------------------------------- You can respond by visiting: https://sourceforge.net/tracker/?func=detail&atid=376685&aid=871649&group_id=22866 ------------------------------------------------------- This SF.net email is sponsored by: IBM Linux Tutorials. Become an expert in LINUX or just sharpen your skills. Sign up for IBM's Free Linux Tutorials. Learn everything from the bash shell to sys admin. Click now! http://ads.osdn.com/?ad_id=1278&alloc_id=3371&op=click _______________________________________________ JBoss-Development mailing list [EMAIL PROTECTED] https://lists.sourceforge.net/lists/listinfo/jboss-development
