Java is back. To be sure, it never really left, but it did appear to take a backseat during the past decade. While new, lightweight, mobile-friendly languages rose to prominence, Java—saddled with cumbersome frameworks and an uncertain future—seemed destined to be used only by the most traditional of enterprises.
But that didn’t happen. It wasn’t just enterprises that depended on Java, but innovative startups. And heavyweight Java frameworks evolved into more approachable, simple-to-use tools. Case in point: the open-source Spring dependency injection framework. Spring’s been a mainstay of Java development for years, but its XML-heavy configuration model made it increasingly unwieldy. Enter Spring Boot in 2014. Spring Boot introduced an opinionated, convention-over-configuration model to Spring and instantly improved developer productivity. And now, companies large and small are using it at an astonishing rate.
Spring Cloud followed in 2015. This open-source project included a host of capabilities—including a number of projects from Netflix engineering—for teams building modern web apps and distributed systems. It’s now downloaded hundreds of thousands of times per month.
Behind all this Spring goodness is Pivotal, the company I work for. We’re the primary sponsor of Spring and after joining Pivotal in April, I thought it’d be fun to teach a course on these technologies. There’s just so much going on in Spring Cloud, that I’m doing a two-partner. First up: Java Microservices with Spring Cloud: Developing Services.
In this five-hour course, we look at some of the Spring Cloud projects that help you build modern microservices. In the second part of the course (which I’m starting on soon), we’ll dig into the Spring Cloud projects that help you coordinate interactions between microservices (think load balancing, circuit breakers, messaging). So what’s in this current course? It’s got five action-packed modules:
- Introduction to Microservices, Spring Boot, and Spring Cloud. Here we talk about the core characteristics of microservices, describe Spring Boot, build a quick sample app using Spring Boot, walk through the Spring Cloud projects, and review the apps we’ll build throughout the course.
- Simplifying Environment Managed with Centralized Config. Spring Cloud Config makes it super easy to stand up and consume a Git-backed configuration store. In this module we see how to create a Config Server, review all the ways to query configs, see how to setup secure access, work to configure encryption, and more. What’s cool is that the Config Server is HTTP accessible, so while it’s simple to consume in Spring Boot apps with annotated variables, it’s almost just as easy to consume from ANY other type of app.
- Offloading Async Activities with Lightweight, Short-Lived Tasks. Modern software teams don’t just build web apps. No, more and more microservices are being built as short-lived, serverless activities. Here, we look at Spring Cloud Task explore how to build event-driven services that get instantiated, do their work, and gracefully shut down. We see how to build Tasks, store their execution history in a MySQL database, and even build a Task that gets instantiated by an HTTP-initiated message to RabbitMQ.
- Securing Your Microservices with a Declarative Model. As an industry, we keep SAYING that security is important in our apps, but it still seems to be an area of neglect. Spring Cloud Security is for teams that recognize the challenge of applying traditional security approaches to microservices, and want an authorization scheme that scales. In this module we talk about OAuth 2.0, see how to perform Authorization Code flows, build our own resource server and flow tokens between services, and even build a custom authorization server. Through it all, we see how to add annotations to code that secure our services with minimal fuss.
- Chasing Down Performance Issues Using Distributed Tracing. One of the underrated challenges of building microservices is recognizing the impact of latency on a distributed architecture. Where are there problems? Did we create service interactions that are suboptimal? Here, we look at Spring Cloud Sleuth for automatic instrumentation of virtually EVERY communication path. Then we see how Zipkin surfaces latency issues and lets you instantly visualize the bottlenecks.
This course was a labor of love for the last 6 months. I learned a ton, and I think I’ve documented and explained things that are difficult to find elsewhere in one place. If you’re a Java dev or looking to add some cloud-native patterns to your microservices, I hope you’ll jet over to Pluralsight and check this course out!