README
¶
hashring-go
This is a library that provides consistent hashing with bounded loads.
Overview
The package makes sure that all the keys are distributed uniformly and we operate consistently. We offer all the standard functionality such as Add, Remove and Get operations.
The user can configure what the ReplicationFactor and PartitionCount should be -- bear in mind, that these values can not be chaned after initializing the hashring object with them.
Before rushing in, try to find a combination of values that suits your needs -- also make sure, that your hashing function is uniformly distributing the values around the ring for best performance.
Contributing
Before creating a pull request, create an issue first.
Install
go get github.com/odvarkadaniel/hashring-go
You can find some usage examples in the examples folder.
Documentation
To see a list of all functions, please visit /TODO: Link/.
Examples
As mentioned before, more examples can be seen in the examples folder.
package main
import (
"fmt"
"hash/fnv"
"github.com/odvarkadaniel/hashring-go"
)
type Server string
func (s *Server) String() string {
return string(*s)
}
func Sum64(data []byte) uint64 {
h := fnv.New64()
h.Write(data)
return h.Sum64()
}
func main() {
cfg := hashring.Config{
PartitionCount: 23,
ReplicationFactor: 20,
Hasher: Sum64,
}
buckets := []hashring.Bucket{}
// Create our fake servers
for i := 0; i < 8; i++ {
b := Server(fmt.Sprintf("node%d", i))
buckets = append(buckets, &b)
}
// Create a new HashRing object
ring := hashring.New(cfg, buckets)
key := "test-key"
// Get a bucket that holds the key
bucket := ring.Get(key)
// This should print node7.
fmt.Println(bucket.String())
}
License
This project uses MIT LICENSE, for more details, please see the LICENSE file.
Documentation
¶
Index ¶
- Constants
- type Bucket
- type Config
- type HashFn
- type HashRing
- func (hr *HashRing) Add(bucket Bucket)
- func (hr *HashRing) AvgLoad() float64
- func (hr *HashRing) Buckets() []Bucket
- func (hr *HashRing) Get(key string) Bucket
- func (hr *HashRing) GetLoads() map[string]float64
- func (hr *HashRing) GetPartitionBucket(id int) Bucket
- func (hr *HashRing) GetPartitionID(key string) int
- func (hr *HashRing) Remove(key string)
Constants ¶
const ( DefaultPartitionCount = 71 DefaultReplicationFactor = 20 )
Variables ¶
This section is empty.
Functions ¶
This section is empty.
Types ¶
type Config ¶
type Config struct {
// Hasher is the hash function that we use to disribute the keys
// in the hash ring.
Hasher HashFn
// ReplicationFactor determines the number of virtual nodes we
// put into the hash ring (replication of a real node on the ring).
ReplicationFactor int
// PartitionCount determines how many time we want to partition the space
// to make for more uniform distribution of keys. Select a prime number for
// this.
PartitionCount int
}
type HashRing ¶
type HashRing struct {
// contains filtered or unexported fields
}
func (*HashRing) AvgLoad ¶
AvgLoad computes the average load. For more information, please see: https://blog.research.google/2017/04/consistent-hashing-with-bounded-loads.html
func (*HashRing) GetPartitionBucket ¶
GetPartitionBucket gets a bucket for a given partition id.
func (*HashRing) GetPartitionID ¶
GetPartitionID gets a partition id for a given key in the ring.
Source Files
Directories