Based on how your application works, you can do the following:

• For applications with all or mostly cacheable content, ensure that your CDN or Varnish cache settings are set to hold onto content for at least an hour on the night of the maintenance event. This ensures that your unauthenticated end users can see the content on your site, even when the site is down for maintenance.

  However, this approach is ineffective for applications with authenticated traffic or uncached content. For example, your sites cannot be rendered properly without write access to the file system or database, even when users browse content and not trigger any actions.

• Empty your cache tables and backup, and delete any file system or database content that might reduce the size of either on each environment. You must complete this step before the maintenance event starts, so that the visitors of your site do not experience a reduction in performance.

Typically, smaller file systems and databases can be upgraded quicker than the larger ones.