One anti-pattern I’ve observed in networked Akka applications is a tendency to forget that it is, well, networked and to treat the network as a friendly place. How does that look like? Well, consider the following piece of code:
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actorOnDifferentNode.tell(veryImportantMessage, sender()); |
Akka’s default message sending mechanism is the fire-and-forget tell method. And that works great – until it doesn’t. See, tell … Read More
Whilst I have always successfully discouraged my clients from using Akka Remoting in their application, I often get questions regarding remoting while talking about anti-patterns at conferences and user groups. Don’t get me wrong. I love Akka remoting. Especially the new Aeron-based Artery remoting version that is based on UDP rather than TCP. Whilst it maintains the same delivery guarantees, … Read More
Lagom is a framework for building reactive microservices in Scala or Java with an emphasis on developer productivity. I’ve had a chance to work with it for some time and would like to share my impressions about it. This is going to take a bit longer than just one post, so you’re reading part one of a 3-part series: Part … Read More
An overview of Akka anti-pattern articles Basics Shared mutable state Blocking Flat actor hierarchies / Mixing businesss logic and failure handling Race conditions Performance Logging the wrong way Being out of touch with the hardware Using Java Serialization (to be written) Network / Cluster Using remoting Trusting the network Always using the defaults (to be written) Architecture Too many actor … Read More
Akka Streams is a powerful implementation on top of the Reactive Streams SPI for non-blocking asynchronous communication with back-pressure on the JVM. This post is not about explaining what this means, nor what Akka Streams does. The purpose of this post is to explain what on earth the NotUsed type in type signatures of Akka Streams is all about which … Read More
This is probably one of the most frequent (and dangerous) anti-patterns when it comes to working with Akka. Let’s look at an adequate description of the mindset you must be in in order to use it: So maybe you didn’t actually want to see the world burn. Maybe you thought that this one time it was okay to call blocking … Read More
There’s a scene in the 1987 classic movie Dirty Dancing in which Johnny (Patrick Swayze) explains the concept of dancing space to Baby (Jennifer Grey). “Lock your frame. Lock it, lock it, lock it. Look. Spaghetti arms. This is my dance space, this is your dance space. I don’t go into yours, you don’t go into mine. You got to … Read More
I recently got myself a new desktop computer with nice and fast hardware (more about this in another post) and am setting up Ubuntu Gnome on it. Since I’ll still be using my MacBook Pro for some time I don’t want to learn another set of keyboard shortcuts, so I set out to use IDEA’s OS X 10.5+ keyboard bindings … Read More
Choosing Akka as a tool is often – if not always – driven by the need for good performance. Surely, the actor model itself is appealing as a means for organizing and reasoning about code, but this isn’t in itself a good reason enough to use the Akka toolkit. If all you are concerned about is a nice way to … Read More
Update: removed rogue toString call in the second code example, since it was unnecessary (and harmful). Debugging actor systems is no small feat, even when there is IDE support for it. In fact, debugging any asynchronous system for that matter is a rather complicated task. Which is why, especially during development, it is not entirely uncommon to rely on DEBUG … Read More
