With so many people running microservice workloads, it is inevitable that organizations keep bumping into the same set of problems: state management, resiliency, event-handling, and more. Dapr exists to help codify the best practices for building microservice applications into building blocks that enable you to build portable applications with the language and framework of your choice. Each building block is completely independent and you can use one, some, or all of them in your application to solve common microservice problems. ...

In my last post I detailed how to setup a local Kubernetes development cluster using kind. This post shows how to leverage this new cluster when developing a system or application that relies on multiple microservices using tilt. If you haven’t setup your local environment with kind yet, refer back to my last post before continuing on. Installing Tilt You can install the tilt binary using Homebrew or through curl and an installation script: ...

kind is a tool built for running local Kubernetes clusters using Docker containers as nodes. kind was primarily designed for testing Kubernetes itself, but it is actually quite useful for creating a Kubernetes environment for local development, QA, or CI/CD. This blog post shows you how to setup a kind-based environment for local development that can mimic a production Kubernetes environment. A fully functioning environment using kind includes a few different components. For our purposes, we will install the following list of software. ...

It’s a dangerous business, Frodo, going out your door. Kubernetes and public cloud infrastructure introduce a few layers of abstraction between users and our services. This article unravels some of those layers to help understand what, exactly, happens between the time a user makes a request to a Kubernetes service running in AWS and when the user receives a response. It’s helpful to start by framing a request in terms of the network boundaries involved, so let’s start there. ...

VoltDB is an in-memory database borne out of the H-Store research project spearheaded by Michael Stonebraker. Within that project, Michael started with the premise of building a fully transactional database with the best possible performance by using insights gathered from an in-depth study on database performance that completely removed disk access — the primary limiting factor on database performance. By removing disk access completely, we end up with a completely in-memory database where we can make additional optimizations like removing write-ahead logging, buffer management, and locks and latches. This effort resulted in the research database H-Store which was commercialized as the in-memory database VoltDB. This article takes a deeper dive into VoltDB to understand how it works and where you may benefit from this approach. ...

When working with Spring Boot, some auto-configuration can happen seemingly by magic. For example, in a traditional Spring application with Java-based configuration, you might configure an H2 database using the following block of code to set the type of the database and run some scripts to initialize it: @Bean public DataSource dataSource() { return new EmbeddedDataSourceBuilder() .setType(H2) .addScript("taco_schema.sql") .addScripts("user_data.sql", "ingredient_data.sql") .build(); } With Spring Boot, you can remove this entire block of code and use auto-configuration. If the H2 dependency is available in the classpath, Spring Boot will automatically create the DataSource and add it as a Bean to Spring’s application context and apply SQL scripts as long as they are named schema.sql or data.sql. Spring Boot does this auth-configuration by leveraging the Spring environment that collects the set of properties available to a Java application and uses those properties to configure beans in Spring’s application context. The following figure from Spring in Action shows how the Spring environment is generated by some of the available configuration property sources available in a typical Java application. ...

Many OCaml guides and tutorials refer to the OCaml toplevel, but what exactly is this thing? In short, the toplevel is OCaml’s Read-Eval-Print-Loop (repl) allowing interative use of the OCaml system. You can consider the toplevel an alternative to compiling OCaml into an executable. In this mode, the OCaml system is configured to repeatedly read phrases from input, typecheck, compile, and evaluate them, then print the inferred type and result value. ...

I’m a fan of Java. If you haven’t given it a chance in a while, you may not have noticed that, Java has quietly been adopting some of the best practices that make dynamic and functional languages so appealing, without sacrificing the many hundred person-years of effort that have made Java and the JVM a world-class development environment. Java is still one the world’s most popular programming languages with roughly 9 million programmers using Java. It doesn’t make sense to ignore all of that history and development effort because of a niggling feeling that Java is a little too verbose, or that XML is so last year. ...

Inversion of Control (IoC), also known as Dependency Injection (DI), allows an object to define their dependencies as constructor arguments (strictly speaking, you can set these dependencies as properties, but the examples I will use today are constructor-based). This is the inverse of the object itself controlling the instantiation or location of its dependencies, hence the name Inversion of Control. Let’s look at an example from Stackoverflow using a text editor with a spell checking component: ...

After recently setting up a new machine and going through the exercise of setting up a development environment for the nth time, I was frustrated by having to install and configure all of my plugins and dependencies to support auto-completion, syntax highlighting, and the other niceties I’ve come to enjoy with Vim. Looking for an alternative, I was drawn to Visual Studio Code (VS Code) with the VSCodeVim extension. Combining Vim key-bindings with Code’s excellent extension marketplace, I was able to recreate and in some cases improve the development environment I enjoyed as a Vim user in VS Code. This blog post continues that discovery by setting up a brand new OCaml project and development environment in VS Code. ...