Activating your Lumen caching configuration

Candidate Slot

The "Candidate" slot should be used when you want to test a new configuration version with a small portion of production traffic. Adding a configuration to the "Candidate" slot will allow you to serve a part of your traffic (1%, 5% or more) to this new configuration, and verify that this new configuration doesn’t introduce any errors or issues to your production traffic using our Real Time Monitoring or Log Streaming. Meanwhile the rest of the traffic is served to the configuration occupying the "Current" slot.  

Once you have completed your tests and have enough confidence in the new configuration, you can increase the Candidate traffic share by clicking on "Edit Traffic Allocation".

"Traffic percentage" increases are made by you at the pace you desire. Each increase in traffic to the candidate slot causes a corresponding decrease to the current slot. Once the traffic adjustments reach 100%, and the changes candidate configuration is fully vetted, the candidate configuration should be promoted to the "Current" slot causing the candidate slot to be removed until it is needed again. You can do this by clicking on "Edit Traffic Allocation", and then "Promote" the configuration to "Current" slot.

Conversely, if the candidate configuration results in negative outcomes, the candidate slot traffic percentage can be rapidly reduced, even to 0%, or the slot can be deleted. In that case, all the traffic rolls back to the "Current" configuration already in place.

If your service is in the process of being migrated to Version 3, you may notice that staged activation is foundational. In this case, a Lumen engineer is cautiously rolling out your migrated configuration in the candidate slot, while your premigration configuration continues to serve the rest of the traffic until the migration candidate configuration is fully approved.

The current and candidate slot configurations should have the same properties unless you want to exclude a specific property and no longer serve its production traffic or add a new property.

The traffic allocation settings are applied to every active property (which you can see in the property registry). The traffic allocation for a property in one slot always equals 100% minus the allocated traffic from the other slot. Therefore, if a property is not present in one slot, it will be applied to 100% of the network.

Media Portal to help vet your candidate configuration.

There are several tools you might find useful during a staged activation interval.
 

• Use logs to look for anomalies. Logs provide you with splits per slot (current / candidate) which help you  detect statistically significant anomalies even when testing with a tiny percent of production traffic
  
  
  • To activate this feature, please contact your account manager or CDNsupport@lumen.com
    
    
• Use caching Real-Time metrics to look for anomalies, perhaps more than usual 5XXs, etc.
  
  
• Use CDN Usage Reports (historical usage stats) if your staged activation spans several days or weeks.
  
  
• Set alerts to be automatically notified based on trigers you define.
  
  

Learn more about monitoring your service.

In some cases, you might need to directly replace your Current slot Configuration without going through Staged Activation. You are able to do that, by selecting a Configuration, and pushing it directly to the Current slot. This action will replace the Configuration that was in the Current slot, and will start serving 100% of your traffic to the newly pushed configuration as soon as the activation is complete.

The Lumen CDN receives all CDN property settings as a collection, via the configuration activation process. Upon success, the properties contained in the configurations are added to the property registry. Each CDN property that is added is active by default and ready to affect edge traffic. Properties are never deleted, but they can be deactivated by activating a configuration that does not contain a property that is already in the registry. The property registry is displayed on the lower portion of “production” page.

In order to bind traffic domains to the Lumen CDN edge domains, you’ll need to create DNS CNAME records in your DNS system for Primary Aliases of your active properties.

CNAME stands for Canonical Name Record and is a type of resource record in the Domain Name System that maps one domain name to another. Each time a configuration is deployed to a production slot, CNAMES are created for all new properties. To ensure you have the correct CNAME, Visit the "CNAME" table found in the lower portion of "Production" tab's landing page.

Learn more about making DNS changes

Each "activation action" - promitng a new version of a configuration to current or candidate slot, changing traffic allocation, etc., - is deplyoed to the network, which takes 10 or more minutes. With every promotion of a new configuration / new version of a configuration to either of the slots, the "environment" version for the production slot is increased by 1. Note that this is different than the configuration version. Each activation action causes a transaction record to be created in "Transaction History", and a recor is uniquely identified by a transaction ID. Visit the "Environment History" tab to become more familiar with environment versions and transactions.