When using an extremely simple protocol stack the app will respond with a NullPointerException. ----------------------------------------------------------------------------------------------- Key: JGRP-446 URL: http://jira.jboss.com/jira/browse/JGRP-446 Project: JGroups Issue Type: Bug Affects Versions: 2.4.1 SP1 Environment: Windows XP java version "1.5.0_11" Java(TM) 2 Runtime Environment, Standard Edition (build 1.5.0_11-b03) Java HotSpot(TM) Client VM (build 1.5.0_11-b03, mixed mode) Reporter: Anders Persson Assigned To: Bela Ban Priority: Minor When using an extremely simple protocol stack the app will respond with a NullPointerException. The communication will however work (at least when running all parties on the same machine). The stack used: <protocol_stacks> <stack name="standard" description="Multicast stack intended for usage on internal highspeed networks."> <config> <UDP mcast_addr="228.15.15.15" mcast_port="45566"/> <PING timeout="2000"/> </config> </stack> <stack name="slow" description="Multicast stack intended for usage on external slow connections."> <config> <UDP mcast_addr="228.15.15.15" mcast_port="45567"/> <PING timeout="2000"/> </config> </stack> </protocol_stacks> Starting DrawMultiplexer using the stack above will generate the following stack trace 2007-mar-26 16:51:24 org.jgroups.JChannelFactory connect SEVERE: failed sending SERVICE_UP message java.lang.NullPointerException at org.jgroups.mux.Multiplexer.generateServiceView(Multiplexer.java:953) at org.jgroups.mux.Multiplexer.handleServiceUp(Multiplexer.java:781) at org.jgroups.mux.Multiplexer.sendServiceUpMessage(Multiplexer.java:224) at org.jgroups.JChannelFactory.connect(JChannelFactory.java:372) at org.jgroups.mux.MuxChannel.connect(MuxChannel.java:126) at org.jgroups.demos.DrawMultiplexer.start(DrawMultiplexer.java:44) at org.jgroups.demos.DrawMultiplexer.main(DrawMultiplexer.java:29) I traced the "problem" to be the lack of a pbcast.GMS entry. (You can try it by removing that entry in the conf/stacks.xml file in your distribution.) Some additional information: In order to get DrawMultiplexer to "communicate" you will have to start two instances using the stack above. Then press "leave" in the window that pops up as a result of the FIRST instance started. (Don't know the inner workings of the DrawMultiplexer app, I don't have to resort to these kinds of actions to get my own app to communicate.) The reason I would like to see this fixed is that I don't want to have NullPointerExceptions in the log file when deploying this at the customer. The reason for my very simple protocol is that we intend to use JGroups in a configuration where one server pumps out data in a stream to a varying number of clients and we don't care if the data was received correctly or not since the stream of data is repeated every six seconds. -- This message is automatically generated by JIRA. - If you think it was sent incorrectly contact one of the administrators: http://jira.jboss.com/jira/secure/Administrators.jspa - For more information on JIRA, see: http://www.atlassian.com/software/jira