During a server update, what is the best practice for ensuring application availability?

Performing updates during off-peak hours is best practice for ensuring application availability because it minimizes the impact on users who rely on the system for their daily tasks. By choosing a time when user activity is at its lowest, the likelihood of interrupting critical operations is greatly reduced. This strategic timing allows the update process to occur with less risk of causing disruptions or downtime that could affect business processes.

While notifying users of potential downtime and backing up applications before an update are important practices, the main focus of maintaining availability during the update is to avoid interruptions during peak usage times. Simultaneously updating all nodes can lead to complete unavailability of the service during the update, making it a less favorable option.