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VMware vSphere App HA is virtual appliance introduced with vSphere 5.5.
vSphere App HA works with vSphere HA host and virtual machine (VM) monitoring to improve application uptime and provide high availability (HA). The feature can restart an application service if it detects a failure and can reset a VM if the application fails to restart.
VSphere App HA uses VMware vFabric Hyperic to monitor applications. Hyperic stores and manages App HA policies, which are configured in the administration section of the vSphere Web Client. Policies define items such as the number of times vSphere App HA will attempt to restart a service, the number of minutes it will wait for the service to start and when to reset a VM if a service is unstable.