Akamai’s Global Traffic Manager, or GTM for short, is technology that allows a user to configure traffic to be sent to more than one data center, or at least more than one origin URL. For an Akamai primer, go here.
In our case, we used it to facilitate A-B testing.
We could have accomplished the same thing with any smart load balancer than handles DNS load balancing, such as the F5 GTM.
We configured Akamai’s GTM to point 50% of our traffic to origin address A, and 50% to origin address B. We then configured our internal F5 LTM to direct requests for origin address A to our servers that hosted code base A, and requests to origin address B to servers that hosted code base B.
As noted, we could have run the GTM piece in our F5 GTM. Technically, we could have done the entire thing in the LTM. If the user didn’t have a cookie, we would randomly distribute the initial request to one of two servers. The software then sets a cookie, and subsequent requests are persisted based on either:
1) an existing mapping of that session to a backend server if the session has not expired
2) or to one of the two pools based on the cookie the last time the user visited
However, as soon as we would like to span data centers, we are back to needing a GTM in some form or fashion.
We configured the Akamai GTM by clicking through the screens shown below.