Posts

Command Query Responsibility Segregation (CQRS) is a pattern that causes quite a lot of confusion. With the popularity of microservices and the event-based programming model, it is important to know what CQRS is. In this article, I will provide you with a simple explanation. To understand CQRS it is important to get some basic terms and concepts right. The first that often appears next to CQRS is CRUD. What is CRUD? CRUD stands for Create, Read, Update and Delete. When you think about this, this is what most basic software systems do. You have some records, you may want to read some records, update them, create or delete. ...

I have recently spoken at a meetup about Practical Choreography with Spring Cloud Stream . It was a great event where I was asked many questions after the talk. One question got me thinking: *“What book about Spring Cloud do you recommend?”*which as it turns out boils down to “How do you learn Spring Cloud?”. I heard that question posed a few times before in different ways. Here, I will give you my answer on what I think is the best way of learning Spring Cloud. ...

JSON Binding (JSON-B) is the new Java EE specification for converting JSON messages to Java Objects and back. JSON is used everywhere and so far we had two main ways of dealing with JSON conversion in Java- using either Jackson or GSON. With the introduction of JSON-B, we have a standard way of handling this conversion. In this article, we will see how Spring Boot 2.0 supports JSON-B, how easy it is to use it and how does it compare with the other options. ...

As part of me running this blog, I have decided to create a mailing list and a semi regular newsletter. This is the first edition of that newsletter. If you would like to join it and receive the content to your email, you can sign up here . I have started this blog on the 13th January 2018, hoping to share my passion, knowledge and experience with the like minded people online. The first blog post: Starting a blog – why? gives a bit more insights. So far this journey has been amazing. ...

I have recently spent quite a lot of time playing with Spring Cloud Data Flow (SCDF). It is an amazing platform that can be used for many things. Talking about it with some of my colleagues I realized that not everyone knows what are the common use cases. Thinking about it further I realized that I don’t know the full scope of capabilities and business problems that it can solve! In this article I look at different uses for Spring Cloud Data Flow based on what the platform offers and actual stories from companies using it in production. The examples come from Spring One Platform 2017 conference. ...

Last week I wrote about getting Started with Spring Cloud Data Flow . This week I want to show you a few more things that you can do with this amazing platform. In this article I will show you how to make your own Apps that can be part of Data Flow Streams and how to use the Data Flow Shell to control the platform. I assume here that you know how to get you Data Flow up and running and you are familiar with the basics of the platform. If not- don’t worry! Check out my Getting Started with Spring Cloud Data Flow article to learn the basics. ...

When talking about microservices (or agile development), the idea of self-managed, independent teams often comes up. What is not emphasized enough is how vital this idea is to the successful adoption of such highly decoupled architecture. In this article, I will share my experiences about working with independent teams and being part of them. Most successful projects that I was either part of, or had a pleasure of working with had one thing in common. They were delivered by either one or a multiple of high-performing, self-managed, independent teams. You may say: every sizable project nowadays is delivered by a team! I disagree, most medium and large projects are delivered by groups of people, but in many cases, I would not call them teams. In my opinion, it takes more than grouping a few people together and slapping a name on them to make a team… ...

On the 15th February 2018 I had a pleasure to speak at The JVM Roundabout Meetup in London. My topic was “Practical Choreography with Spring Cloud”. The idea behind the talk was to give practical advice on introducing choreography into microservices architecture. The emphasis is on practical. Choreography can be intimidating, especially for those not familiar with the pattern. Since I am a big advocate of Spring Cloud and I think it is a great framework for newcomers and experts alike, I demonstrate how it can be used to make that adoption easier. ...

In this article, I will show you how you can get started with Spring Cloud Data Flow. Spring Cloud Data Flow is an amazing platform for building data integration and processing pipelines. It has a very user-friendly graphical dashboard where you can define your streams, making your work with data an absolute pleasure. The goal of this article is to have you learn to build some simple data pipelines by the time you are finished reading. Before we get started there are a few system requirements: ...

HATEOAS – Hypermedia as the Engine of Application State, a name long enough to intimidate and confuse. Behind this complicated name we have a rather simple and elegant idea. In this blog post, I explain what HATEOAS is and how it can be practically used to build more stable systems. HATEOAS is a way of designing a REST API. More precisely it is a specific constraint of a REST architecture. It can be summed up with: ...