reactivesocket

reactivesocket-js

ReactiveSocket Protocol for Client/Server for JS. Also comes with a CLI.

npm install -g reactivesocket

This library only supports the request/response, setup and error interactions. More interactions are coming soon.

Streams

The transport for this library is built entirely on top of the Node.js Stream API. As a result, it is agnostic to the underlying transport mechanism. As long as you pass in a transport stream that is a Node.js Duplex stream, this library will work.

Using streams means that this library natively supports backpressure regardless of the transport implementation.

We currently target TCP via the net module, and WebSockets via the yws-stream module. You are of course, free to inject other transports.

Connection Quick Start

This library supports 3 classes of clients. A fully managed load balancer, which automatically manages a pool of connections and takes care of automatically reconnecting and load-balancing connections from the pool. A fully managed single TCP connection, which can be configured to automatically reconnect if the TCP connection disconnects. Lastly a "raw" ReactiveSocket connection, which doesn't include any retry or transport logic. You provide a transport stream to plug in to the connection. This is the most flexible client, as you can use it with any transport mechanism. Examples for TCP and WebSockets are provided.

TCP Client Side Load Balancer

var bunyan = require('bunyan');
var reactiveSocket = require('reactivesocket');
 
var connectionPool = reactiveSocket.createTcpLoadBalancer({
    size: 5, // size of the pool, defaults to 5
    log: bunyan.createLogger({name: 'rsLoadBalancer'}),
    hosts: [{ // array of host:port objects to connect to
        host: 'localhost',
        port: 1337
    },{
        host: 'localhost',
        port: 1338
    },{
        host: 'localhost',
        port: 1339
    },{
        host: 'localhost',
        port: 1340
    },{
        host: 'localhost',
        port: 1341
    },{
        host: 'localhost',
        port: 1342
    },{
        host: 'localhost',
        port: 1343
    }]
});
 
connectionPool.on('ready', function () {
    var stream = connectionPool.getConnection().request({
        metadata: 'You reached for the secret too soon, you cried for the moon',
        data: 'Shine on you crazy diamond.'
    });
 
    stream.on('response', function (res) {
        console.log('got response', res.getResponse());
    });
 
    stream.on('application-error', function (err) {
        console.error('got error', err);
    });
 
    stream.on('error', function (err) {
        console.error('got rs connection error', err);
    });
});
 

TCP Connection

var bunyan = require('bunyan');
var reactiveSocket = require('reactivesocket');
 
var tcpConnection = reactiveSocket.createTcpConnection({
    log: bunyan.createLogger({name: 'rsConnection'}),
    connOpts: { // host to connect to
        host: 'localhost',
        port: 1337
    },
    reconnect: true // whether to reconnect if the TCP connection dies
});
 
tcpConnection.on('ready', function () {
    var stream = tcpConnection.getConnection().request({
        metadata: 'You reached for the secret too soon, you cried for the moon',
        data: 'Shine on you crazy diamond.'
    });
 
    stream.on('response', function (res) {
        console.log('got response', res.getResponse());
    });
 
    stream.on('application-error', function (err) {
        console.error('got error', err);
    });
 
    stream.on('error', function (err) {
        console.error('got rs connection error', err);
    });
});

Raw TCP

var net = require('net');
 
var bunyan = require('bunyan');
var reactiveSocket = require('reactivesocket');
 
 
// Create any transport stream that's a Node.js Duplex Stream.
var transportStream = net.connect(1337, 'localhost', function (err) {
    var rsConnection = reactiveSocket.createReactiveSocket({
        log: bunyan.createLogger({name: 'rsConnection'}),
        transport: {
            stream: transportStream,
            framed: true // TCP requires explicit framing
        },
        type: 'client',
        metadataEncoding: 'utf8',
        dataEncoding: 'utf8'
    });
 
    rsConnection.on('ready', function () {
        // returns a reactive socket stream
        var stream = rsConnection.request({
            metadata: 'You reached for the secret too soon, you cried for the moon',
            data: 'Shine on you crazy diamond.'
        });
 
        stream.on('response', function (res) {
            console.log('got response', res.getResponse());
        });
 
        stream.on('application-error', function (err) {
            console.error('got error', err);
        });
    });
});

Raw WebSocket

var bunyan = require('bunyan');
var reactiveSocket = require('reactivesocket');
 
var Ws = require('ws');
var WSStream = require('yws-stream');
 
 
var websocket = new Ws('ws://localhost:1337');
 
// Create any transport stream that's a Node.js Duplex Stream
var transportStream = new WSStream({
    log: bunyan.createLogger({name: 'ws-stream'}),
    ws: websocket
});
 
// Wait for Websocket to establish connection, before we create an RS Connection
websocket.on('open', function() {
 
    var rsConnection = reactiveSocket.createReactiveSocket({
        log: bunyan.createLogger({name: 'rsConnection'}),
        transport: {
            stream: transportStream
        },
        type: 'client',
        metadataEncoding: 'utf8',
        dataEncoding: 'utf8'
    });
 
    rsConnection.on('ready', function () {
        // returns a reactive socket stream
        var stream = rsConnection.request({
            metadata: 'You reached for the secret too soon, you cried for the moon',
            data: 'Shine on you crazy diamond.'
        });
 
        stream.on('response', function (res) {
            console.log('got response', res.getResponse());
        });
 
        stream.on('application-error', function (err) {
            console.error('got error', err);
        });
    });
});

Timeout

As a convenience for the user, the ReactiveSocket client provide 'timeout' events. Below is an example of how to listen to those events.

var socket = ...;
var client = reactiveSocket.createReactiveSocket({
    log: LOG,
    transport: {
        stream: socket,
        framed: true
    },
    requestTimeoutMs: 100,
    type: 'client',
    metadataEncoding: 'utf-8',
    dataEncoding: 'utf-8'
});
 
client.on('ready', function () {
    var responseStream = CLIENT_CON.request({data: 'request-data'});
 
    responseStream.once('response', function (res) {
        console.log('Yeah, a response ' + res.getResponse());
    });
    responseStream.once('timeout', function () {
        console.log('Too late ');
    });
});

Lease Semantic

ReactiveSocket client allows you to specify if you want to honor the lease semantic.

reactiveSocket.createReactiveSocket({
    ...,
    lease: true,
    ...
});

If you don't, it means that the ReactiveSocket is ready as soon as the connection is established, and you can start sending messages. But if you do, it means the client has to wait for a LEASE frame from the server before sending messages.

Note that nothing is preventing the client to send requests to the server before receiving the LEASE, the LEASE reception only update the return value of the availability method (number between 0 and 1.0).

The availability method gives precious information to a potential higher level library (e.g. load-balancing library) about the capability of the underlying connection.

More details about the lease semantic are available in the protocol Spec.

Metrics

ReactiveSocket uses the metrix library to collect and export metrics. By default, the library doesn't collect any metrics, and then its usage doesn't have any impact on the performance of ReactiveSocket.

To enable the collection, you need to pass a Recorder when creating a ReactiveSocket, and listen to this Recorder with an Aggregator.

E.g.

var RECORDER = metrix.createRecorder();
var AGGREGATOR = metrix.createAggregator(RECORDER);
 
var client = reactiveSocket.createReactiveSocket({
    transport: {
        stream: myStream,
        framed: true
    },
    recorder: RECORDER,
    type: 'client',
    metadataEncoding: 'utf-8',
    dataEncoding: 'utf-8'
});
 
setInterval(function () {
    var report = AGGREGATOR.report();
    var json = JSON.stringify(report);
    console.log(json)
}, 60*1000);

CLI

This library comes with a CLI. You can use it by installing this module.

$ npm install -g reactivesocket

RS Client

There are two versions of the client CLI. The simple CLI makes one request to a server.

$ rs -o req tcp://localhost:1337 'if you didnt care what happened to me, And I didnt care for you'

There is also a benchmarking CLI in the vein of Apache Bench

$ rb -c 10 -n 10000000 -s 1000 tcp://localhost:1337
{ 'elapsed time (s)': 10.529176232,
  'total reqs': 137133,
  RPS: 13024.095805636622,
  'median (ms)': 0.649035,
  'mean (ms)': 0.75758988656268,
  '0.1% (ms)': 0.457949,
  '1% (ms)': 0.498248,
  '5% (ms)': 0.544133,
  '10% (ms)': 0.565295,
  '20% (ms)': 0.596515,
  '30% (ms)': 0.616699,
  '40% (ms)': 0.633112,
  '50% (ms)': 0.649035,
  '60% (ms)': 0.671943,
  '70% (ms)': 0.708819,
  '80% (ms)': 0.772095,
  '90% (ms)': 0.905283,
  '99% (ms)': 4.441137,
  '99.9% (ms)': 6.004325,
  '99.99% (ms)': 32.613085,
  '99.999% (ms)': 101.189893 }

Echo Servers

Simple echo servers are also available for both TCP and Websocket.

TCP

$ HOST=localhost PORT=1337 rs-tcp-server

WebSocket

$ HOST=localhost PORT=1337 rs-ws-server

Contributions

Contributions welcome, please ensure make check runs clean.

License

MIT

Copyright 2016 Yunong J Xiao