From Monolith to Microservices: When and Why to Migrate

What to Keep in Mind When Migrating to Microservices

So you’ve decided to go microservices. Now what? Here is what’s important to keep in mind:

1. Have a Good Repository Setup: Mono repo and multi repo have their pros and cons. Choose wisely since this will have an impact on your CI/CD pipelines.
2. Communication: Microservices can use synchronous or asynchronous communication, such as message bus communication. Distinguish between both to design the system better. Implementing patterns like Service Registry and Service Discovery will help not only in communication but also in scalability.
3. Data: You must consider whether you go for the approach of API composition, event sourcing, or Two Phase commit in order to guarantee your data integrity. Choosing the right pattern will help you in handling data access, storage, and manipulation.
4. Failover Tolerance and Monitoring: Now you have multiple points of failure. This is why monitoring is key, including implementing health checks, good logging techniques (like process traceability), and working with logs aggregation technologies (i.e., ElasticSearch, Kibana Stack, Splunk, Loggly, etc.), many of which allow you to set up alerts and even create dashboards.

A Real World Scenario

A client came to Tekton looking for a scalable solution for his business, which had already been in the market for many years and had the potential to keep growing. We evaluated different options and took the one that best suited the final goal. An Azure cloud solution was proposed using a microservices architecture.

These microservices were deployed in a Kubernetes cluster. The communication between frontend and backend was done through API Management as the only entry point (Plus, the security benefits APIM provides were leveraged). Furthermore, we implemented asynchronous communication between microservices within the cluster and synchronous communication when calling external services. Because we need to be aware of every activity and have proper response time to any incident, monitoring was accomplished through health checks, Azure Monitor, application insights, dashboards, alerts, and application logs (Loggly).

Finally, we are a company that had already adopted a DevOps culture, so choosing Scrum as the agile methodology was evident, they both work well together, and Scrum helps us to achieve high agility when delivering value to our customers. A mono-repo approach was chosen, this allowed us to execute continuous integration (CI) pipelines using Gitlab, and we obtained deployment independence by having each sub-repo configured correctly. Our deployments to non-prod environments were done automatically, but deployments to production were done following Continuous Delivery since the client had requested that deployments have his approval.

Final Thoughts

Going from monolith to microservices is not a decision you should make lightly. It requires deep analysis and an understanding of what this task involves and the needs of the business. We hope this article has helped you as a starting point for doing microservices and doing it right.