I just wasted the better part of a day to identify why deployment of my webapp on JBoss AS 7.0.1.Final failed. It would have been a lot easier if the error message had been more verbose than:
16:10:42,184 ERROR [org.jboss.as] (MSC service thread 1-2) JBoss AS 7.0.1.Final "Zap" started (with errors) in 6884ms - Started 240 of 339 services (42 services failed or missing dependencies, 57 services are passive or on-demand)
16:10:42,403 INFO [org.jboss.as.server.controller] (DeploymentScanner-threads - 2) Deployment of "A3Z_eZIVI.war" was rolled back with failure message Operation handler failed to complete
16:10:42,403 INFO [org.jboss.weld] (MSC service thread 1-9) Stopping weld service
16:10:42,543 INFO [org.jboss.as.server.deployment] (MSC service thread 1-9) Stopped deployment A3Z_eZIVI.war in 143ms
16:10:42,543 ERROR [org.jboss.as.deployment] (DeploymentScanner-threads - 1) {"Composite operation failed and was rolled back. Steps that failed:" => {"Operation step-2" => "Operation handler failed to complete"}}
The root cause was that the jdbc driver (which I had deployed as JAR as recommended on http://community.jboss.org/wiki/DataSourceConfigurationInAS7 ) was not "deployed" because its deployment had been marked as "failed". (i.e. the file jboss/standalone/deployments/ojdbc6.jar.failed existed).
This came about by copying the ojbc.jar into the deployments directory manually, then deploying the webapp and starting the server using JBoss Tools. The JBoss application server than somehow recognized the ojdbc.jar, did a composite deployment of both the webapp and the driver, and when deployment of the web application failed for unrelated reasons, rolled back the deployment of ojdbc.jar, too. When I then redeployed the webapplication, JBoss Tools cleared the ".failed"-marker for the webapp, but not for ojdbc.jar, causing the latter to be ignored in future deployment attempts ...
It would be nice if JBoss Tools worked more seamlessly with JBoss AS.
I hope this post will assist in rectifying these defects, or at least spare others the pain of having to hunt down why their webapps won't deploy.