After jboss application server is turned off and immediately turned back on - we notice that it fails to start due to missing dependencies. If we restart the app server again it boots fine. This occurs on our 3 node cluster.
The default configurations for a jboss cluster leaves the scan-interval value at 0. This can cause the app server to fail to start with missing dependencies depending on your environment.
Before making any modifications to the standalone-full-ha.xml file please ensure you save a backup of the file.
1) Edit the standalone-full-ha.xml and search for "deployment-scanner" you should find a similar line to this.
<deployment-scanner path="deployments" relative-to="jboss.server.base.dir" scan-enabled="true" scan-interval="0" auto-deploy-exploded="true" deployment-timeout="600"/>
2) update the scan-interval to "5000" and save the file.
3) restart the application server and you should no longer experience this issue.