QBit Java Micorservices lib tutorials| QBit Website | QBit uses Reakt | QBit works with Vert.x | Reakt Vertx

QBit - The Microservice Lib for Java - JSON, REST, WebSocket, Speed!

Quick overview of QBit

The Java microservice lib. QBit is a reactive programming lib for building microservices - JSON, HTTP, WebSocket, and REST. QBit uses reactive programming to build elastic REST, and WebSockets based cloud friendly, web services. SOA evolved for mobile and cloud. ServiceDiscovery, Health, reactive StatService, events, Java idiomatic reactive programming for Microservices.

Got a question? Ask here: QBit Google Group.

Everything is a queue. You have a choice. You can embrace it and control it. You can optimize for it. Or you can hide behind abstractions. QBit opens you up to peeking into what is going on, and allows you to pull some levers without selling your soul.

QBit is a library not a framework. You can mix and match QBit with Spring, Guice, etc.

New and Improved!

QBit now supports Reakt invokable promises for local and remote client proxies. This gives a nice fluent API for async programming.

Invokeable promise

        employeeService.lookupEmployee("123")
               .then((employee)-> {...}).catchError(...).invoke();

QBit callbacks are now also Reakt Callbacks without breaking the QBit contract for Callbacks.

See Reakt Invokable Promises for more details.

QBit is FAST!

Getting started

Using from maven

QBit is published to the maven public repo.

<dependency>
    <groupId>io.advantageous.qbit</groupId>
    <artifactId>qbit-admin</artifactId>
    <version>1.10.0.RELEASE</version>
</dependency>
<dependency>
    <groupId>io.advantageous.qbit</groupId>
    <artifactId>qbit-vertx</artifactId>
    <version>1.10.0.RELEASE</version>
</dependency>

Using from gradle

compile 'io.advantageous.qbit:qbit-admin:1.10.0.RELEASE'
compile 'io.advantageous.qbit:qbit-vertx:1.10.0.RELEASE'

Core Features

• Write REST based async microservices
• Write WebSocket based async microservices (fast async RPC over WebSocket)
• Actor Service Queues using micro-batching for high-speed message passing
• Strongly async typed event bus which can be distributed
• Async low overhead metrics gathering which can be queried and distributed (for doing fast lane analytics)
• Complex async call coordination (with the Reactor) for reactive programming
• Built-in support for health checks (and integration with tools like Consul)
• Built-in support for monitoring (and integration with wire protocols like StatsD)
• Built-in support for Service Discovery (with integration with health system, DNS SRV records and Consul)
• Integration with persistent queues
• 12 factor app port bindings, health checks, KPI gathering, Logging MDC
• API Gateway support for client generation and consumption via Swagger.
• Our services can generate Swagger files (like idl for JSON/REST).
• Remote client proxies for WebSocket (your interface is your IDL)

Status

Deployed at several large fortune 100 companies. QBit now works with Vertx (standalone or embedded). You can also use QBit on non-QBit projects, it is just a lib.

License

Apache 2

Java Microservice Lib

QBit has inproc services, REST microservices and WebSocket microservices as well as an in-proc service event bus (which can be per module or per app). It supports workers and in-memory services.

Before we describe more, here are two sample services:

Todo Service

@RequestMapping("/todo-service")
public class TodoService {

    @RequestMapping("/todo/count")
    public int size() {...

    @RequestMapping("/todo/")
    public List<TodoItem> list() {...

Adder Service using URI params

    @RequestMapping("/adder-service")
    public class AdderService {

        @RequestMapping("/add/{0}/{1}")
        public int add(@PathVariable int a, @PathVariable int b) {...
    }

QBit philosophy:

At the end of the day QBit is a simple library not a framework. Your app is not a QBit app but a Java app that uses the QBit lib. QBit allows you to work with Java UTIL concurrent, and does not endeavor to hide it from you. Just trying to take the sting out of it.

Does it work

We have used techniques in Boon and QBit with great success in high-end, high-performance, high-scalable apps. We helped clients handle 10x the load with 1/10th the servers of their competitors using techniques in QBit. QBit is us being sick of hand tuning queue access and threads.

Boon and QBit humility policy

Ideas for Boon and QBit often come from all over the web. We make mistakes. Point them out. As a developer of Boon and QBit, we are fellow travelers. If you have an idea or technique you want to share, we listen.

Inspiration

A big inspiration for Boon/QBit was Vertx, Akka, Go Channels, Active Objects, Apartment Model Threading, Actor, and the Mechanical Sympathy papers.

QBit has ideas that are similar to many frameworks. We are all reading the same papers. QBit got inspiration from the LMAX disruptor papers and this blog post about link transfer queue versus disruptor. We had some theories about queues that blog post inspired us to try them out. Some of these theories are deployed at some of the biggest middleware backends and whose name brands are known around the world. And thus QBit was born.

QBit also took an lot of inspiration by the great work done by Tim Fox on Vertx. The first project using something that could actually be called QBit (albeit early QBit) was using Vertx on an web/mobile microservice for an app that could potentially have 80 million users. It was this experience with Vertx and early QBit that led to QBit development and evolution. QBit is built on the shoulders of giants (Netty/Vertx).

Does QBit compete with...

Spring Disruptor: No. You could use QBit to write plugins for Spring Disruptor I suppose, but QBit does not compete with Spring Disruptor. Spring Boot/Spring MVC: No. We use the same annotations but QBit is geared for high-speed in-memory microservices. It is more like Akka than Spring Boot. QBit has a subset of the features of Spring MVC geared only for microservices, i.e., WebSocket RPC, REST, JSON marshaling, etc. Akka: No. Well Maybe. Akka has similar concepts but they take a different approach. QBit is more focused on Java, and microservices (REST, JSON, WebSocket) than Akka. LMAX Disruptor: No. In fact, we can use disruptor as on of the queues that QBit uses underneath the covers.

(Early benchmarks have been removed. They were here. QBit got a lot faster. Benchmarking QBit is a moving target at the moment. Links and reports will be created.)

Code Examples

Basic Queue example (REST style services is further down)

====

     BasicQueue<Integer> queue =  BasicQueue.create(Integer.class, 1000);

    //Sending threads

     SendQueue<Integer> sendQueue = queue.sendQueue();
     for (int index = 0; index < amount; index++) {
           sendQueue.send(index);
     }
     sendQueue.flushSends();
     ...
     sendQueue.sendAndFlush(code);
     //other methods for sendQueue, writeBatch, writeMany


     //Receiving Threads
     ReceiveQueue<Integer> receiveQueue = queue.receiveQueue();
     Integer item = receiveQueue.take();
     //other methods poll(), pollWait(), readBatch(), readBatch(count)

What is QBit again?

QBit is a queuing library for microservices. It is similar to many other projects like Akka, Spring Reactor, etc. QBit is just a library not a platform. QBit has libraries to put a service behind a queue. You can use QBit queues directly or you can create a service. QBit services can be exposed by WebSocket, HTTP, HTTP pipeline, and other types of remoting. A service in QBit is a Java class whose methods are executed behind service queues. QBit implements apartment model threading and is similar to the Actor model or a better description would be Active Objects. QBit does not use a disruptor (but could). It uses regular Java Queues. QBit can do north of 100 million ping pong calls per second which is an amazing speed (seen as high as 200M). QBit also supports calling services via REST, and WebSocket. QBit is microservices in the pure Web sense: JSON, HTTP, WebSocket, etc. QBit uses micro batching to push messages through the pipe (queue, IO, etc.) faster to reduce thread hand-off.

QBit lingo

QBit is a Java microservice lib supporting REST, JSON and WebSocket. It is written in Java but we could one day write a version in Rust or Go or C# (but that would require a large payday).

Service POJO (plain old Java object) behind a queue that can receive method calls via proxy calls or events (May have one thread managing events, method calls, and responses or two one for method calls and events and the other for responses so response handlers do not block service. One is faster unless responses block). Services can use Spring MVC style REST annotations to