To meet the evolving needs for business or consumer applications, especially higher demand for mobile, the pace of change is vastly accelerating for IT and developer teams. Monolithic systems that have most or all of the service side functionality on a single system is not scalable and reactive enough for large concurrent user loads typical with many mobile deployments, and the process of modifying a mobile app and getting the update installed on each user’s device is not a speedy one. Enterprises are seeking ways to move more functionality to back end services and rapidly make enhancements without requiring a full mobile app refresh deployment. Although microservices have been around for some time, they have recently risen in popularity thanks to availability of more targeted APIs, particularly REST APIs, which provide an interface gateway to a host of microservices that developers can use to leverage functionality and data they need to create applications.
Now, big and small companies alike are using microservices. Take the biggest cloud providers, like Amazon - who have been using microservices for years. Amazon Web Services is a prime example of microservices because there are smaller services in big collections that all work together. We’re seeing more IT shops and companies use them, but typically it’s harder for them to implement because they have a lot of legacy systems, which are monolithic by nature and more difficult to convert to microservices. Microservices sit in front of legacy systems and might have a certain function - like calling SAP instead having a user tied to SAP directly. Cloud companies have leveraged microservices the most, and you’re starting to see IT layer in microservices to their architecture.
Benefits of Microservices
A microservices architecture is very conducive to continuous development and deployment iterations. As the DevOps environment becomes more focused on rapid deployment, adaptability and growth, microservices are the perfect tool to build versatile systems that allow for continuous improvement and scaling with little to no down time for the user. By breaking down a large suite of features into discrete functions, where each runs as its own service that is not tied to any specific server or dependencies, developers are able to create a loosely coupled system of independent functionalities. In all, each microservice can do one or a few things very well.
Continuous delivery
This allows each microservice to have specific development teams that are responsible for the functionality on that service. They can enhance the microservice without impacting other services. Each team can work on each one independently and, bringing each together, they make a larger solution. This also solves the huge issue of teams running into each other. You can deploy or move changes into production separately from other teams, making updating and deploying easier. It’s also easier to practice agile development with microservices versus monolithic architectures.
Scalability
Each microservice can also be scaled on its own. By using containers and orchestration, you can create multiple instances of the same microservice or you can add more as your user base or demand grows, so you can scale much quicker.
Resilience
Because microservices perform limited functions that run independently, an architecture using them is more adaptable to failure. Unlike a monolithic system, if one microservice has an issue, the scope of impact can be less severe. Microservices running as multiple instances in an orchestrated environment can recover faster when issues arise and decrease system availability risks.
Enhancements
It’s much simpler to enhance an existing microservice, or introduce a brand new service to the overall system.
Data
Each microservice is going to work with some data - it may be a database that a microservice is connected to. The microservice may access data from another system or might call another microservice and ask it to calculate. The microservice gets a request, gets data and returns what is needed back to requester very quickly. A cluster of microservices working together is a powerful way to scale heavy duty computations with large data sets.
Tips for implementing microservices
- Have a plan. Microservices are advantageous but consequently a lot more for development teams to manage since you have to keep up with each microservice. It’s important to think in terms of services from the beginning if you’re architecting - how would you break it into smaller pieces? Think through the right scaling architecture - whether it’s Docker plus Kubernetes, Mesos, or other forms of container orchestration - to minimize downtime and ensure they can handle incremental loads and capacity without users knowing anything has changed.
- Limit the scope. Focus each service on one area of functionality. Don’t be tempted to pile up a lot of scope in a single service. A discipline of limiting each service to specific responsibilities will ensure your system maintains the scale, resilience and agility you need for the long term. Likewise plan on approaching development using agile practices to create, enhance and deploy each service.
- Define your messaging system. How microservices will talk to each other should be part of the architecture, and you need to have an event mechanism for microservices messaging. When talking to each other, options for inter-microservice communication can be in the form of direct REST API interfaces, publish-subscribe, or other messaging methods for listening and acting upon events. And microservices are ultimately useless if you they aren’t logging everything they’re doing. In case a security breach, functional, or performance issue happens, you’ll want to have an event capture mechanism in place to trace it.
- Leverage no-code/low-code platforms. Microservices have to be built with coding, but no-code platforms can call a web service to request data and return it much more quickly. Microservices are a back end functionality and important as a scalable architecture, while low-code/no-code platforms quickly build the front end and make it easier to consume the back end services. Ultimately you want to provide value to your users, and web and mobile front ends are the UI that leverages the capabilities provided by back end services. No-code platforms help you scale development and take advantage of microservices really fast and easily.
Monolithic app categories no longer meet the needs of today’s enterprise users. Business processes are changing and they are crossing process and app boundaries. As the line between consumer and business apps blurs, old categories like front-, middle-, and back-office no longer apply. Instead, data and processes must come together around user needs, delighting customers, partners, and employees. APIs will help to democratize microservices, pushing these high-level functions down to business users in easily consumable forms.