What policy should a system administrator develop for when an application server is no longer needed?

The development of a decommissioning policy is essential for effectively managing the retirement of an application server that is no longer needed. This policy outlines the procedures and considerations necessary to safely and securely remove an application from the operational environment.

The decommissioning process typically includes steps for data preservation, ensuring that any critical or sensitive information is properly archived or securely deleted to mitigate risks of data breaches. It also encompasses the evaluation and documentation of the application server's end-of-life status, the reallocation or disposal of hardware and resources, and compliance with relevant regulations or organizational standards.

While the backup retention policy pertains to how long data backups need to be retained, it does not address the steps needed when an application server is being retired. The data encryption policy is focused on securing data at rest or in transit, which is also not directly related to the process of decommissioning an application. Lastly, the application lifecycle policy covers the stages of an application's development and ongoing management but does not specifically deal with the process of safely phasing out an application system. Hence, the decommissioning policy is the most appropriate choice for this scenario.