一致性哈希 consistent-hash

Implementing Consistent Hashing in Kotlin

Java Kotlin实现的一致性哈希工具

简单示例

val a = HostPortPhysicalNode("A", "192.169.1.1", 8080)
val b = HostPortPhysicalNode("B", "192.169.1.2", 8080)
val c = HostPortPhysicalNode("C", "192.168.1.13", 8888)

val consistentHash = ConsistentHashHelper.create<HostPortPhysicalNode>()
        .withNodes(listOf(a, b))
        .build()

consistantHash.getNode("manerfan")
consistantHash.getNode("linxi")

consistentHash.add(c)
consistantHash.getNode("linxi")

consistantHash.remove(a.hashKey())
consistantHash.getNode("manerfan")

自定义物理节点

实现PhysicalNode接口及hashKey方法，ConsistantHash将通过hashKey的返回计算节点的哈希值

自定义哈希函数

实现HashFunc接口及hash方法

ConsistentHashHelper

使用ConsistentHashHelper快速构造ConsistentHash

withHash(Hash)方法用于指定自定义哈希函数

withNodes(Collection<PhysicalNode>[, ReplicasNum])用于在构造ConsistentHash时初始化节点，同时可指定每个节点的副本个数

val a = MyPhysicalNode("192.169.1.1", 8080)
val b = MyPhysicalNode("192.169.1.2", 8080)

val consistentHash = ConsistentHashHelper.create<MyPhysicalNode>()
        .withHash(customHash)
        .withNodes(listOf(a, b))
        .build()

ConsistentHash

add(PhysicalNode[, ReplicasNum]) 动态增加节点，同时可指定副本个数

remove(key) 动态删除节点

getNode(key) 计算该key应该落到的物理节点