ring

Go utility to build Peer to Peer Architecture easily.

Ring Configuration parameters

Parameters	Type	Usage
BindAddr	string	The address that Ring will bind to for communication with other members on the ring.
Tags	map[string]string	Tags will be sent with NodeName when a new member joins the ring.
NodeName	string	Unique node name to identify this member.
SeedAddresses	[]string	Addresses of other members to join upon start up.
VirtualNodeCount	int	Number of virtual nodes to create on the ring for this member.
HashFunction	HashFunction	Hash function to calculate position of the server on the ring.
MemberType	MemberType	Type of the membership: 1. ShardMember 2. LoadBalancerMember.
Timeout	time.Duration	Sets the timeout in the network in handling connections.
Logger	hclog.Logger	Human readable output mode in development and JSON mode for production.

Quick Start

Create a new ring member. LoadBalancerMember member has the list of all types of members.

import (
// Other dependencies....
"github.com/Brijeshlakkad/ring"
)

ringMember, err := ring.NewRing(ring.Config{
    NodeName:           "Unique_node_name_0", // Node name.
    SeedAddresses:      []string{},       // Addresses of other members to join upon start up.
    BindAddr:           "127.0.0.1:7946", // The address that Ring will bind to for communication with other members on the ring.
    Tags:               map[string]string{      // Tags to be sent to other members upon joining the ring.
        "rpc_addr": "127.0.0.1:1234",
        "custom_key": "custom_value"
    },
    VirtualNodeCount:   3, // This will create 3 virtual nodes on the ring.
    MemberType:         LoadBalancerMember, // This member will not take part in the sharding, but has the list of members (ShardMember) who is responsible for sharding. 
})

Use ringMember#AddListener method to add a new handler to be notified when new node joins on the ring. Look at this Handler interface to implement your own handler.

ringMember.AddListener(listenerId string, handler Handler)

Use ringMember#AddListener method to remove the handler from listening to the joining/leaving of other members. All the handlers' RemoveListener will get called when the member shutdowns.

ringMember.RemoveListener(listenerId string)

Upon join a listener will receive the below parameters in the function call:

1. rpcAddr - RPC address of the new member that has joined the ring.
2. vNodeCount - Number of virtual nodes of the new member on the ring.

Can I contribute to this project?

Feel free to create a PR, I’m more than happy to review and merge it.

What's the long-term goal?

• Onboard videos and documentation
• Clean code, full test coverage and minimal tech debt
• This utility will evolve over time!!!

References

1. Serf
2. https://en.wikipedia.org/wiki/Consistent_hashing
3. https://pdos.csail.mit.edu/6.824/papers/paxos-simple.pdf
4. https://github.com/RichardKnop/paxos