Which two components can be installed in monitored virtual machines to trigger vSphere HA Application Monitoring? (Choose two.)
A. A custom script utilizing the appmonitor executable
B. The vSphere Fault Tolerant agent
C. Third-party utilities such as Neverfail or ApplicationHA
D. The vSphere HA application agent
Correct Answer: AD
Explanation/Reference:
The vSphere High Availability (HA) feature for ESXi hosts in a cluster provides protection for a guest OS and applications running in a virtual machine by restarting the virtual machine if a guest OS or application failure occurs.
1. The HA feature provides this reset capability through two different mechanisms:
2. Guest OS heartbeat issued by the VMware Tools process, known as VM Monitoring.
Heartbeat issued by a program that uses the HA Application Monitoring SDK to communicate with the VMware Tools process and the vSphere HA agent, known as Application Monitoring. This mechanism involves local monitoring by the program, thus avoiding the overhead of sending messages to and from vCenter Server. Heartbeat and Status Signals depicts the monitoring and reset capability of host and virtual machine.
Heartbeat and Status Signals
Using the HA Application Monitoring SDK, developers can write application monitoring programs in the C or C++ language.
The application monitoring program sends an enable request to start the monitoring, followed by a heartbeat signal. The vSphere infrastructure passes the signal up from your HA application monitoring program to the virtual machine, and then to the ESXi host. The HA monitoring agent will reset the virtual machine if the application monitoring program stops sending a heartbeat signal.
http://pubs.vmware.com/vsphere-51/index.jsp?topic=%2Fcom.vmware.guestsdk.pg.doc%2Fguest_sdk_HAappmon.5.2.html
