Parallel Universe
Blog

  • Reactive (Dataflow) Programming in Java and Clojure with Quasar and Pulsar

    We cover the basic concepts and building-blocks of Reactive programming, give examples in Java and Clojure using both the imperative and functional styles, and contrast concurrency with parallelism

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  • Writing an MMO with Web Actors

    To see how web actors can be used in production, we have ported our spaceships demo from a standalone simulation to an MMO.

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  • Implementing, Abstracting and Benchmarking Lightweight Threads on the JVM

    In this blog post, we'll describe how Quasar fibers are implemented, and how they are abstracted to seamlessly run alongside plain Java (OS) threads, as well as benchmark their performance.

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  • Little's Law, Scalability and Fault Tolerance: The OS is your bottleneck (and what you can do about it)

    Little's Law helps us determine the maximum request rate a server can handle. When we apply it, we find that the dominating factor limiting a server's capacity is not the hardware but the OS. Should we buy more hardware if software is the problem? If not, how can we remove that software limitation in a way that does not make the code much harder to write and understand?

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  • Writing Interactive Web Applications with Web Actors

    The actor model is a great way to program modern interactive web applications. To that purpose, Comsat provides server-side Web Actors, that easily handle HTTP requests, WebSockets, and SSE streams. They let you write fast, simple, fault tolerant web applications with advanced features like hot code swapping. Lets look at an example.

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  • Introducing COMSAT and the Parallel Universe Stack

    We are happy to announce the launch of our latest open source product: COMSAT. Parallel Universe now provides a complete server-side stack, with Comsat at the web layer, Quasar for the application logic, and Galaxy for clustering and fault tolerance. SpaceBase, along with a future highly-concurrent non-spatial database called Dark Matter, form the database layer. This stack helps you write performant, highly scalable, and fault tolerant software, that takes full advantage of modern multi-core hardware, while at the same time emphasizes a simple programming model.

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  • No More Callbacks: 10,000 Actors, 10,000 Threads, 10,000 Spaceships

    We've re-written our spaceships demo so it uses Quasar actors, as well as the newly released SpaceBase 2.0, which integrates with Quasar. While written in Java rather than in a concurrency-oriented language, the demo uses Quasar's API which is heavily based on ideas taken from Erlang and Clojure

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  • Distributed Actors in Java and Clojure

    One of the main additions to Quasar/Pulsar 0.2.0 is distributed actors, which let actors discover one another and exchange messages in a cluster. 

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