Experimental Features in the SAS Viya Platform
As of SAS Viya platform releases after December 2021, SAS Environment Manager includes a Features page which allows SAS Viya platform administrators to toggle the display and availability of pre-production features to users. The features in this context are ones that are ready for users to try out but may or may not be promoted to production at some later date. For deployments at SAS, the Features settings are used to provide early access to appropriate testing groups for quality testing. For deployments outside of SAS, administrators can decide to expose any available feature listed on the Features page all users or just targeted groups of users.
In this post I will highlight the different types of features that can be exposed to users and look at how administrators can expose experimental features.
Intended Audiences
There are two primary audiences for features managed by the Features page:
- Internal SAS testing
- Customers (e.g., Business partners, Early adopters, Partners).
The sas-feature-flags service, which manages the availability of features exposed to users, behaves differently for deployments at SAS ("internal") and customer deployments ("external"). As you might expect, the number of features available for testing is significantly higher for internal deployments so that features can be exposed to the appropriate testing teams. External orders only have access to features that are approved for external exposure and some of those features require special licensing to activate. Depending on the situation, it is possible that the Features page for external deployments may not offer any optional features.
Types of features
There are three types of features that are managed with the Features page:
- Experimental features
- Permissioning features
- Release toggle features.
Experimental features are ready to be tested and may or may not be promoted to production quality. Regardless, the feature will at some point disappear from the Features list. Experimental features appear in both internal and external deployments and are the most common type of feature exposed to customers. Activation of an experimental feature requires acknowledgement that the feature is pre-production and the administrator must accept an agreement to activate the feature.
Permissioning features require a license to use and as such, are intended primarily for use by customers who have been asked, or offered, to test certain features. The customer can decide whether or not to activate the feature and the feature only appears in the administrators list if it is permitted by the license. An example of this type of feature is one that might be exposed to a development partner for targeted feedback as the feature is being developed.
Release toggle features appear only on internal deployments. These features can be made active and turned on by default when the feature is deemed 'ready' which speeds it into a production-ready testing state without needing to remove the old code first. The result is exposure to all users as if the feature is already in production.
Managing Experimental Features
External deployments offer feature control only at the administrator level and the list of available features is usually quite limited. Depending on the situation, it is very possible for the Features list to be empty so do not be alarmed if there are no features displayed in your deployment.
Experimental features are inactive by default so the administrator must activate any feature they want to expose to their user community. When the Active checkbox is selected, the administrator will be asked to agree to a notification that they are providing access to a pre-production feature.
In this example, the administrator has activated the Upload data from Excel feature but set the Default value to False. This may seem contradictory but notice that the Data Builders group was added to the Exceptions list. So, although the Upload data from Excel feature active, it is unavailable (i.e., false) for everyone except users in the Data Builders group. This is one way for administrators to limit feature access to specific subsets of users.
Feature values Default value and Exceptions work in combination as shown in this table from the SAS Viya Platform Administration documentation.
What happens if a feature is removed or gets promoted to production?
At some point, every feature will either be promoted to production or removed in a subsequent update of the SAS Viya platform.
If the feature moves to production in a later update, which is the more likely outcome, the feature will disappear from the Features list without the administrator having to do anything. Users will gain access to the feature as dictated by the normal availability rules for products.
If the feature is removed in a later update, the sas-feature-flags service will automatically remove the feature and it will no longer be available to any users. Again, no action by the administrator is required.
Wrapping up
SAS Viya platform administrators can use the Features page in SAS Environment Manager to toggle the display and availability of pre-production features to users.
Providing early access to features allows users to test, comment on, and direct development of future features of the SAS Viya platform.
Find more articles from SAS Global Enablement and Learning here.
