1. A system for automatic migration of poller proxy services in an application server cluster, comprising: one or more computers, each including a microprocessor; an enterprise service bus (ESB) cluster, executing on the one or more computers, that includes a plurality of managed servers, and one or more poller proxy services deployed thereon, wherein each poller proxy service is homogeneously deployed on each managed server and associated with a poller engine configured to run on a single managed server; a poller singleton application and a cluster change listener registered therewith, wherein the cluster change listener listens for any state change in the cluster; wherein the poller singleton application operates to receive a notification that a managed server fails in the cluster, determine one or more poller engines configured to run on the failed managed server, determine one or more running managed servers in the cluster, and migrate each of the poller engines from the failed managed server to a running managed server.