Microservices.io is brought to you by Chris Richardson. Experienced software architect, author of POJOs in Action and the creator of the original CloudFoundry.com. His latest startup is eventuate.io, a microservices application platform.
Chris offers a comprehensive set of resources for learning about microservices including articles, an O'Reilly training video, and example code. Learn more
Chris offers a comprehensive consulting services, workshops and hands on training classes to help you use microservices effectively. Get advice
I'll be there in May! Contact me
Want to see an example? Check out Chris Richardson's example applications. See code
Cross cutting concerns
Join the microservices google group
When you start the development of an application you often spend a significant amount of time putting in place the mechanisms to handle cross-cutting concerns. Examples of cross-cutting concern include:
As well as these generic cross-cutting concerns, there are also cross-cutting concerns that are specific to the technologies that an application uses. Applications that use infrastructure services such as databases or a message brokers require boilerplate configuration in order to do that. For example, applications that use a relational database must be configured with a connection pool. Web applications that process HTTP requests also need boilerplate configuration.
It is common to spend one or two days, sometimes even longer, setting up these mechanisms. If you going to spend months or years developing a monolithic application then the upfront investment in handling cross-cutting concerns is insignificant. The situation is very different, however, if you are developing an application that has the microservice architecture. There are tens or hundreds of services. You will frequently create new services, each of which will only take days or weeks to develop. You cannot afford to spend a few days configuring the mechanisms to handle cross-cutting concerns. What is even worse is that in a microservice architecture there are additional cross-cutting concerns that you have to deal with including service registration and discovery, and circuit breakers for reliably handling partial failure.
Build your microservices using a microservice chassis framework, which handles cross-cutting concerns
Examples of microservice chassis frameworks:
The major benefit of a microservice chassis is that you can quickly and easy get started with developing a microservice.
You need a microservice chassis for each programming language/framework that you want to use. This can be an obstacle to adopting a new programming language or framework.
There are the following related patterns: