Is your dream to build a service like cassandra,kafka,zipkin,jaeger,redis,etc...? You are in the right place , join ring-election project !!!

What the ring-election driver offers you ?

• A default partitioner that for an object returns the partition to which it is assigned.
  
• Mechanism of leader election
  
• Failure detection between nodes.
  
• Assignment and rebalancing of partitions between nodes
  
• Automatic re-election of the leader
  
• Listen for new assigned/revoked partitions
  

What problems can you solve with this driver ?

• Scalability
  
• High availability
  
• Concurrency between nodes in a cluster
  
• Automatic failover
  

  npm i ring-election --save

Example You do not need to choose a node as leader , just indicate all your nodes and start everyone as follower.
The first node to start will be the leader , the leader do not have assigned partitions so try to start 2 instances after your integration

How to integrate

const ring = require('ring-election')
let follower = ring.follower
const {
  BECOME_LEADER,
  PARTITIONS_ASSIGNED,
  PARTITIONS_REVOKED
} = ring.constants;
follower.createClient()
// if you want REST API as monitoring , invoke startMonitoring
follower.startMonitoring()
// to get ring info
ring.follower.ring()
// to get assigned partitions
let assignedPartitions = ring.follower.partitions()
// now let me assume that a follower will create some data
// and you want to partition this data
let partition = ring.follower.defaultPartitioner('KEY')
// save your data including the partition on a storage
// you will be the only one in the cluster working on the partitions assigned to you.

// If you want to handle partitions assigned
// ( use other constants to listen other events ) you can do in this way.
ring.follower.eventListener.on(PARTITIONS_ASSIGNED , (newAssignedPartitions) => {
   // DO STUFF
})

Start your development cluster

You will find some helpful files into the dev folder , please see the following video

Watch the video

Check assigned partitions to local:9000/status or change the port to 9001/9002

Try to stop and restart processes and observe the behaviour.

This section introduce you on what you can build on top of ring-election using it as driver/library.

Distributed Scheduler
Each Scheduler instance will work on the assigned partitions .
A real implementation of this use case is available here https://github.com/pioardi/hurricane-scheduler

Distributed lock
Distributed cache
Distributed computing

Try it out !

   docker image build -t ring-election .
   docker-compose up

See wiki page.

See contributing guidelines CONTRIBUTING