forked from TrueCloudLab/hrw
e5d4b47881
* Work around Hashing and tests * fixes * add TravisCI * fix lint * so slow * add badges * work on README * Improved tests and get rid of fnv (#3)
56 lines
No EOL
1.8 KiB
Markdown
56 lines
No EOL
1.8 KiB
Markdown
# Golang HRW implementation
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[](https://travis-ci.org/im-kulikov/hrw)
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[](https://codecov.io/gh/im-kulikov/hrw)
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[](https://goreportcard.com/report/github.com/im-kulikov/hrw)
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[](https://github.com/im-kulikov/hrw)
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[Rendezvous or highest random weight](https://en.wikipedia.org/wiki/Rendezvous_hashing) (HRW) hashing is an algorithm that allows clients to achieve distributed agreement on a set of k options out of a possible set of n options. A typical application is when clients need to agree on which sites (or proxies) objects are assigned to. When k is 1, it subsumes the goals of consistent hashing, using an entirely different method.
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## Install
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`go get github.com/im-kulikov/hrw`
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## Example
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```go
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package main
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import (
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"fmt"
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"github.com/im-kulikov/hrw"
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)
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func main() {
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// given a set of servers
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servers := []string{
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"one.example.com",
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"two.example.com",
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"three.example.com",
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"four.example.com",
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"five.example.com",
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"six.example.com",
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}
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// HRW can consistently select a uniformly-distributed set of servers for
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// any given key
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var (
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key = []byte("/examples/object-key")
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h = hrw.Hash(key)
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)
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hrw.SortSliceByValue(servers, h)
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for id := range servers {
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fmt.Printf("trying GET %s%s\n", servers[id], key)
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}
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// Output:
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// trying GET four.example.com/examples/object-key
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// trying GET three.example.com/examples/object-key
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// trying GET one.example.com/examples/object-key
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// trying GET two.example.com/examples/object-key
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// trying GET six.example.com/examples/object-key
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// trying GET five.example.com/examples/object-key
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}
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``` |