Applications can be deployed concurrently across a network cluster by
utilizing a phased approach to deployment. A preparation operation is
invoked each node on which an application is to be deployed. The
preparation operation can utilize two phases, in which the deployment
descriptors for an application are analyzed and in which each node is
initialized for deployment. For each node that is successfully
initialized, an activation phase is started in which the node is informed
that it should prepare for requests on the application. The deployed
application is then started on each successful node. For each node on
which the preparation operation was unsuccessful, the deployment can be
rolled back or attempted again.