Feature Overview

• The customer is experiencing long VM restart time of ~15 minutes when a host fails. 

Goals

• The expected user outcome is for the VM to restart within seconds on another node in case of a host failure, allowing applications/servers to have minimal downtime.

Requirements

Even with the improvements in FAR (90 seconds to host recovery), this is a small footprint critical system where a failed VM needs to start on another host as quickly as possible, and the failed host rebooted.

Questions to answer

• What system checks or health checks are performed on an IPI installation with the MachineHealthCheck controller?
• With the MachineHealthCheck controller, how much time or range of time will the VM take to restart?

Background, and strategic fit

This Section: What does the person writing code, testing, documenting need to know? What context can be provided to frame this feature.

Documentation Considerations

Questions to be addressed:

• What educational or reference material (docs) is required to support this product feature? For users/admins? Other functions (security officers, etc)?
  • Customer needs a reference material to show what health checks are done in the case of a host failure and best practices they need to take in order to minimize downtime 
• Does this feature have doc impact?
  • Yes
• What concepts do customers need to understand to be successful in [action]?
  • The customer needs further information on the above Questions to Answer
• How do we expect customers will use the feature? For what purpose(s)?
  • They will use this feature to minimize VM downtime due to a host failure
• What reference material might a customer want/need to complete [action]?

• • Documentation listing steps they need to take to remediate host failure and how long the VM may need to take to restart on another node
• Is there source material that can be used as reference for the Technical Writer in writing the content? If yes, please link if available.
  • N/A.
• What is the doc impact (New Content, Updates to existing content, or Release Note)?
  • Release Note