/ConsistentHash

A universal Consistent Hash implementation in Java, which supports virtual nodes and user defined hash function

Primary LanguageJava

Consistent Hash Implementation in Java

Reference http://www.codeproject.com/Articles/56138/Consistent-hashing

Get Started

    //initialize 4 service node
    MyServiceNode node1 = new MyServiceNode("IDC1","127.0.0.1",8080);
    MyServiceNode node2 = new MyServiceNode("IDC1","127.0.0.1",8081);
    MyServiceNode node3 = new MyServiceNode("IDC1","127.0.0.1",8082);
    MyServiceNode node4 = new MyServiceNode("IDC1","127.0.0.1",8084);

    //hash them to hash ring
    ConsistentHashRouter<MyServiceNode> consistentHashRouter = new ConsistentHashRouter<>(Arrays.asList(node1,node2,node3,node4),10);//10 virtual nodes

    String requestIp = "192.168.0.1";
    System.out.println(requestIp + " is route to " + consistentHashRouter.routeNode(requestIp));

Please see MyServiceNode.java for more usage details

Developer Doc

Node

Any class that implements Node can be mapped to ConsistentHashRouter.

VirtualNode

Your custom Node represents a real physical node, which supports numbers of virtual nodes , the replicas of physical node.

When adding new Node to the ConsistentHashRouter, you can specify how many virtual nodes should be replicated.

HashFunction

By default , ConsistentHashRouter will use MD5 to hash a node, you may specify your custom hash function by implementing HashFunction

Contact Author

For any question or feature required, please post a Github issue directly.

To contact author, please mail to linjunjie1103@gmail.com


Java 实现的一致性哈希

原理参考 http://www.codeproject.com/Articles/56138/Consistent-hashing

快速开始

    //初始化4个服务节点
    MyServiceNode node1 = new MyServiceNode("IDC1","127.0.0.1",8080);
    MyServiceNode node2 = new MyServiceNode("IDC1","127.0.0.1",8081);
    MyServiceNode node3 = new MyServiceNode("IDC1","127.0.0.1",8082);
    MyServiceNode node4 = new MyServiceNode("IDC1","127.0.0.1",8084);

    //把节点哈希到哈希环中
    ConsistentHashRouter<MyServiceNode> consistentHashRouter = new ConsistentHashRouter<>(Arrays.asList(node1,node2,node3,node4),10);//10个虚拟节点

    String requestIp = "192.168.0.1";
    System.out.println(requestIp + " is route to " + consistentHashRouter.routeNode(requestIp));

更多的使用的实例请参看: MyServiceNode.java

开发者文档

Node(节点)

任意一个实现了Node接口的类的对象都可以映射到ConsistentHashRouter

VirtualNode(虚拟节点)

自定义的 Node代表一个物理的节点,这些物理节点支持指定一些虚拟节点作为物理节点的复制(replicas)。当需要增加NodeConsistentHashRouter时,你可以指定这个节点需要复制有多少个虚拟节点。

HashFunction(哈希函数)

默认情况下, ConsistentHashRouter 会使用MD5去哈希一个节点,你也可以通过去实现HashFunction指定自己的自定义哈希函数

联系作者