Mixed Mode lets you use the same use case-based behaviors in multiple rules in the same Download Delivery (Download Delivery) property. This lets you simplify the configuration process and also get the best performance, by applying best practices for each use case.

The old way vs. the new way: Mixed Mode Configuration

With a traditional Download Delivery property—the "old way"—the various use case-based behaviors for optimization are limited to the Default Rule in the property, which uses a match criteria of "all requests." A mixed mode configuration (MMC)—the "new way"—lets you set up a single property and include these behaviors in multiple rules, and set up different match criteria.

More Origin Optimization. In the past, you could include multiple origin servers in a single Download Delivery property, but you could only apply a single instance of the Origin Characteristics behavior to optimize access to them. If you needed unique Origin Characteristics for multiple origins, you had to create a completely separate Download Delivery property to handle requests. Now, you can include multiple origins in a single property, along with unique Origin Characteristics, and set up match criteria to direct requests to the applicable origin.
More Content and Client Optimization. Previously, you had to create one property to optimize delivery of specific content to some clients, and a second to optimize its delivery to other clients. Now you can apply multiple instances of the Content Characteristics and Client Characteristics behaviors in a single property, to optimize delivery, based on match criteria you set up for client requests.

What are use case-based behaviors?

There are various behaviors included in the Default Rule with your Download Delivery property, that are used to implement "use case-based provisioning" for delivery of your content. You should familiarize yourself with these "use case-based" behaviors and how they're applied before you start using MMC.

These behaviors are required in the Default Rule of a property for Download Delivery. With MMC, you can include them in additional rules with their own unique match criteria, too. The use case-based behaviors for Download Delivery include:

Property rule and behavior logic, and MMC

When applying rules in a property, the bottom rule in the list is reviewed first: if its match criteria is met by a request for content, the settings in its behaviors are applied for that request. The Default Rule is processed last and its behaviors' settings are applied to all requests. In the case of duplicate behaviors, if the match criteria in all other rules in the property don't match the request, the instance of the behavior in the Default Rule is used.

So, with MMC consider the following:

Use case-based behaviors are required in the Default Rule. If you added a use case-based behavior to a custom rule to support MMC, and that rule's match criteria is not met by a request, the settings applied in the Default Rule for the same use case-based behavior are applied for the request.
Rule logic "trickles down". Rules stack and the last rule listed is read first. If a request does not meet the match criteria in the last rule, the second-to-the-last rule is checked next, and so on. Consider this when applying the same use case-based behavior in multiple rules. For example, you've set up two rules with unique match criteria, along with the Default Rule that applies to all requests. They all contain the "Content Characteristics" behavior. If the match criteria in the second (last) rule isn't matched by a request, the first rule is checked. If that criteria isn't matched, what's set in the Default Rule would be used.
Remember that the Default Rule is still applied to all requests. Behaviors included in the Default Rule, but not in a custom rule are applied to requests, too. So, if you set up a non-use case-based behavior in the Default Rule, its settings are also applied to a request. However, if you set up the same behavior in the custom rule, and that rule's match criteria is met, that behavior's settings are used, rather than what's in the Default Rule.

How to enable MMC

There is no specific enablement required for use. However, MMC is only available in a new Download Delivery property. You can't apply it to the existing version of a property.

You can edit the property to create a new version of it and configure mixed mode support. If you do, we highly recommend that you save the updates to the Staging network and thoroughly test the property before pushing the new version to Production. You can always migrate back to an earlier "working" version of your property if you run into problems.