Application Modernization

One of the Gartner Reports for Information Technology called out the paths to adopting the public cloud as one of Five R’s – Rehost, Refactor, Rearchitect, Rebuild and Retire. Many Solution Architects would tend to agree with such separate workstreams for the progression from assessment through deployment and finally release of the cloud hosted applications. But while the analysts and even customers tend to focus on one approach, the Solution architects often see many paths and even involving intermediary steps between the start and the finish.  While they fine tune the path by optimizing several parameters and often on a case-by-case basis, they generally agree with the break-out of these definitions.

Rehosting is a recommendation to change the infrastructure configuration of the application in order to “Lift and Shift” it to the cloud using Infrastructure-as-a-service.

Refactor is a recommendation to perform modest modifications of the application code without changing the architecture or functionality so that it can be migrated to the cloud in a container using Container-as-a-service or using Platform-as-a-service.

Rearchitect is a recommendation to dramatically modify the application code thereby altering the architecture to improve the health of the application and enable it to be migrated to the cloud using Platform-as-a-service or deployed serverless using Function-as-a-service.

Rebuild is a recommendation to discard the code of the application and develop it again in the cloud using Platform-as-a-service or serverless Function-as-a-service.

Retire is a recommendation to discard the application altogether or potentially replace it with a commercial software-as-a-service alternative.

All of the recommendations above can be made on an application-by-application basis but must be elaborated with additional information such as the Lines of code analyzed, the number of files read, a score or ranking, the total number of full-time employees required, a quantitative assessment for cloud readiness, the number of roadblocks encountered, the estimated effort, Operations and Business Support system dedication, the SR, SA, and SE assessments, and tentative dates for the release.

As you can see, this process can be quite intensive and repeating it for dozens of legacy applications can be quite tedious. Coming up with a table for the results of the rigor across all these applications and for a dashboard to represent the insights via canned queries can easily become error prone. Fortunately, some trail and documentation are maintained as this analysis is conducted and there are quite a few tools that can help with the visualization of the data even as the data is incrementally added to the dataset. An end-to-end automation that can help with detailed analysis, drill downs and articulated charts and graphs is possible if those applications were merely scanned by their source. Indeed, a rapid scan of a portfolio of applications can be a great start in the roadmap that requires us to assess, mobilize, migrate and modernize but iterations will remain inevitable and even desirable as they help towards optimizing continuously.