Streams processing have been around for a while and encompasses a great number of applications: HTTP servers handling stream of incoming HTTP requests Message streams: Twitter hose, user posts, … Time-series messaging: stream from IoT sensors Database querying: result set contains a stream of record …. Most interestingly reactive streams have gain traction over the […]
The actor model allows us to write complex distributed applications by containing the mutable state inside an actor boundary. However with Akka this state is not persistent. If the actor dies and then restarts all its state is lost. To address this problem Akka provides the Akka Persistence framework. Akka Persistence is an effective way […]
The problem Last time we’ve seen how to deal with future inside an actor. However some times you just need to wait for a future to finish before processing the next message.
Future and Actor are two different paradigms to express concurrent computations. Both of them are perfectly valid abstractions. However one must be careful when it comes to mixing them up.
People regularly complains about the lack of type safety within Akka actors. After 2 rather unsuccessful attempts (using byte-code generation at runtime for the first and java proxies for the second) the third attempt seems much more promising. Let’s start with regular non-typed actors to implement a very basic toy example and then move on […]
Stream computing is one of the hot topic at the moment. It’s not just hype but actually a more generic abstraction that unifies the classical request/response processing with batch processing. The request/response is a 1-1 scheme: 1 request gives 1 response. On the other hand the batch processing is an all-all scheme: all requests are […]
Continuing my tour of the Spark ecosystem today’s focus will be on Alluxio, a distributed storage system that integrates nicely with many compute engines – including Spark. What is Alluxio ? The official definition of Alluxio is (or at least that’s how one of its author presents it): Alluxio is an open source memory speed […]
Apache Spark is a computation engine for large scale data processing. Over the past few months a couple of new data structures have been available. In this post I am going to review each data structure trying to highlight their forces and weaknesses. I also compares how to express a basic word count example using […]