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@wzrdtales/swim-ng

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  • License MIT

Gossip protocol based on SWIM

Package Exports

  • @wzrdtales/swim-ng
  • @wzrdtales/swim-ng/index.js

This package does not declare an exports field, so the exports above have been automatically detected and optimized by JSPM instead. If any package subpath is missing, it is recommended to post an issue to the original package (@wzrdtales/swim-ng) to support the "exports" field. If that is not possible, create a JSPM override to customize the exports field for this package.

Readme

swim-js Build Status

JavaScript implementation of SWIM membership protocol

Motivation

Membership management is important to distributed systems and large clusters need a decentralized protocol such as SWIM, which handles failure detection and membership dissemination in a scalable and weakly-consistent way. It can be used to implement functionalities based on membership like distributed consensus, application layer sharding, log replication, etc.

Usage

Installation

npm install swim --save
var Swim = require('swim');
var opts = {
    local: {
        host: '10.31.1.191:11000',
        meta: {'application': 'info'} // optional
    },
    codec: 'msgpack', // optional
    disseminationFactor: 15, // optional
    interval: 100, // optional
    joinTimeout: 200, // optional
    pingTimeout: 20, // optional
    pingReqTimeout: 60, // optional
    pingReqGroupSize: 3, // optional
    suspectTimeout: 60, // optional
    udp: {maxDgramSize: 512}, // optional
    preferCurrentMeta: true // optional
};
var swim = new Swim(opts);
var hostsToJoin = ['10.31.1.192:11000', '10.31.1.193:11000'];

swim.bootstrap(hostsToJoin, function onBootstrap(err) {
    if (err) {
        // error handling
        return;
    }

    // ready
    console.log(swim.whoami());
    console.log(swim.members());
    console.log(swim.checksum());

    // change on membership, e.g. new node or node died/left
    swim.on(Swim.EventType.Change, function onChange(update) {});
    // update on membership, e.g. node recovered or update on meta data
    swim.on(Swim.EventType.Update, function onUpdate(update) {});

    // shutdown
    swim.leave();
});

// or
swim.bootstrap(hostsToJoin);
// bootstrap error handling
swim.on(Swim.EventType.Error, function onError(err) {});
// bootstrap ready
swim.on(Swim.EventType.Ready, function onReady() {});

Additional API Documentation

Benchmark

Benchmark convergence time under different configuration

node bench/script/convergence-time.js -h

  Usage: convergence-time [options]

  Options:

    -h, --help                      output usage information
    --cycles [value]                number of cycles
    --workers [value]               number of workers
    --codec [value]                 msgpack or json
    --dissemination-factor [value]  dissemination factor
    --interval [value]              interval
    --join-timeout [value]          join timeout
    --ping-timeout [value]          ping timeout
    --ping-req-timeout [value]      ping req timeout
    --ping-req-group-size [value]   ping req group size
    --max-dgram-size [value]        max dgram size
node bench/script/convergence-time.js

configuration:
- cycles 10
- workers 10
- codec msgpack
- dissemination factor 15
- interval 20 ms
- join timeout 100 ms
- ping timeout 4 ms
- ping req timeout 12 ms
- ping req group size 3
- max dgram size 512 bytes
convergence time under single node failure
histogram data:
- count 10
- min 76
- max 123
- mean 100
- median 101
- variance 308.44444444444446
- std dev 17.56258649642599
- p75 116.25
- p95 123
- p99 123

License

MIT