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Rohit is an investor, startup advisor and an Application Modernization Scale Specialist working at Google.

Saturday, May 16, 2020

Top Ten Application Modernization Myths

Sometimes we tell little lies to ourselves. It is always good to take inventory of reality and introspect on what is true and what is not. Here are some of the little lies of application migration and modernization that I have observed over the last five years. 
  1. Application has to be 12/15 factors compliant to land on PaaS. Apps can be modified on the cloud native spectrum. The more cloud native idiomatic changes to an app - the more ROI you get from the changes. See Myth #1 "Cloud Foundry can only run cloud-native, 12-factor apps." - FALSE https://tanzu.vmware.com/content/blog/debunking-cloud-foundry-myths
  2. Applications need to be modified by developers before landing them on Kubernetes (TKG). In fact an enterprise can get significant cost savings by migrating one factor apps to Kubernetes. A one factor app simply has the capability to restart with no harmful side-effects See https://tanzu.vmware.com/content/intersect/vmware-tanzu-in-15-minutes Do you even have a 1-factor application?
  3. Once technical debt on an application becomes unsurmountable the only recourse is to rewrite it. Surgical strikes with an emphasis on understanding the core domain can lead to incremental modernization of the most valuable parts of a big critical legacy system. A FULL rewrite is not the only option.  See technical debt like financial debt https://tanzu.vmware.com/content/intersect/risk-profile-of-technical-debt and https://tanzu.vmware.com/content/webinars/may-6-tech-debt-audit-how-to-prioritize-and-reduce-the-tech-debt-that-matters-most
  4. There is a silver bullet for app migration. There is an increasing bevy of tools that have started promising a seamless migration of VMs to containers in the cloud. Remember in life nothing is free. You get what you put in. Migration is highly contextual and the OPEX and Developer efficiency returns are dependent on the workloads being ported. Migration of apps in VMs to Kubernetes stateful sets or automatic dockerization through buildpacks etc should be evaluated for the desired objectives of the Migration Project.
  5. Microservices and event driven architecture is ALWAYS the right architecture choice for app modernization. Sometimes the answer is to step back simplify the domain and implement a modular monolithic system and sometimes the answer is to decompose the large system into a combination of microservices and functions. Understand the design and operational tradeoffs first before making the choice. Every tech choice like eventing, APIs, streaming etc has a spectrum. The fundamental job of an architect is to understand the sociotechnical factors and make the right choices from a process, people and implementation perspective. see https://tanzu.vmware.com/content/practitioners-blog/how-to-build-sustainable-modern-application-architectures
  6. Decomposing and rearchitecture of an existing system can be done concurrently with forward development with little impact to exisrting release schedules. This is a dream. When working on two branches of an existing system a forward development branch and a rearchitecture branch > the total output often times gets worse before becoming better. WBB - This is because there is a period of time where dual maintenance and dual development and the coordination tax across two teams are levied without getting any of the benefits of modularization and refactoring. See The Capability Trap: Prevalence in Human Systems https://www.systemdynamics.org/assets/conferences/2017/proceed/papers/P1325.pdf https://rutraining.org/2016/05/02/dont-fall-into-the-capability-trap-does-your-organization-work-harder-or-smarter/
  7. The fundamental problems of app modernization are technical. If developers  only had the rigor and discipline to write idiomatic code all problems would be fixed and we won't incur technical debt. Wrong- The fundamental problems of app modernization are team and people related. Incorrect team structure, wrong alignment of resources to core domains and messed up interaction patterns are far more responsible for the snail pace for feature addition rather than technical changes. The answer is team re-organization based on the reverse conway maneuver. See Team Topologies https://www.slideshare.net/matthewskelton/team-topologies-how-and-why-to-design-your-teams-alldaydevops-2017
  8. Mainframe modernization can be accelerated by using lift-n-shift tools like emulators or code generation tools. In our experience a complex mainframe modernization almost always involves a fundamental rethink of the problem being solved and then rewriting a new system to address the core domain divorced from the bad parts of the existing intermingled complex system. Theory of constraints and a systems thinking help us reframe the system and implement a better simpler one.
  9. Engineers, Developers and Technical Architects tend to think from a technical nuts and bolts perspective (the “how”) and, therefore, tend to look at modern technologies such as Cloud Foundry, Spring Boot, Steeltoe, Kafka and containerization as the definition of a modern application. This misses the mark. The Swift Method pioneered by Pivotal  helps bridge the gap in understanding between the non-technical, top down, way of thinking and the technical, bottom up thought process.  The end result is an architecture that maps to the way the system “wants to behave” rather than one that is dictated by the software frameworks of du jour. 
  10. AWS or Azure or GKE/GCP etc provide an all encompassing suite of tools, services and platforms to enable and accelerate modernization and migration of workloads. While it is true that the major cloud providers have ALL the bells and whistles to migrate workloads, the economics of app modernization tend towards the app and not the platform. The more cloud native you make the app, the higher the optionality you get since it becomes cloud agnostic allowing enterprises to exact maximum leverage from all the providers. The focus needs to be on the app inside-out to get the best returns. In general the higher you are in the abstraction stack the more performance gains you will get so Architecture changes will yield a 10x more benefit than JVM or GC tuning which will yield a 10x more benefit than tuning assembly code and so on … If it is the database tier that you think is the problem - then you can put in multiple shock absorbers 1. caches 2. queues 3. partitioning first and focused on instead tuning the startup memory and app start times. Apps first, Platform second :-)  

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