Now that we have a high-level idea of CQRS, let's set about designing how to use this pattern to support the query needs for our bookstore app. If you remember correctly, in Chapter 4, Making History with Event Sourcing, we had to remove the comment out of the code that we had previously working to handle multientity queries within our app. We have events for all of our entities stored in Cassandra, via Akka Persistence, currently. Unfortunately, the way this data is stored (binary via protobuf) and the nature of the data itself (events versus actual current state) makes it next to impossible to write queries against it. This means that we can't currently handle things such as looking up books by authors or sales orders by users. In order to get this functionality back, we will have to build read models for our entities.
Mastering Akka
By :
Mastering Akka
By:
Overview of this book
For a programmer, writing multi-threaded applications is critical as it is important to break large tasks into smaller ones and run them simultaneously. Akka is a distributed computing toolkit that uses the abstraction of the Actor model, enabling developers to build correct, concurrent, and distributed applications using Java and Scala with ease.
The book begins with a quick introduction that simplifies concurrent programming with actors. We then proceed to master all aspects of domain-driven design. We’ll teach you how to scale out with Akka Remoting/Clustering. Finally, we introduce Conductr as a means to deploy to and manage microservices across a cluster.
Table of Contents (17 chapters)
Mastering Akka
Credits
About the Author
Acknowledgments
About the Reviewer
www.PacktPub.com
Preface
Free Chapter
Building a Better Reactive App
Simplifying Concurrent Programming with Actors
Curing Anemic Models with Domain-Driven Design
Making History with Event Sourcing
Separating Concerns with CQRS
Going with the Flow with Akka Streams
REST Easy with Akka HTTP
Scaling Out with Akka Remoting/Clustering
Managing Deployments with ConductR
Customer Reviews