HKSample

An algorithm to sample a complete session by hashing its key, and then we see if the keys fits in one the buckets within the sampling percentage.

Installation

 go get github.com/lafikl/hksample

Example

package main

import (
    "log"
    "github.com/lafikl/hksample"
)
func main() {
    hk := NewHKSample(.20)
    key := []byte(`5efe2993-6b3d-48e2-ac94-1afd543d9190`)
    if hk.Sample(key) {
        log.Printf("Sampled: %s", key)
    }
}

Key Features:

• Guarantees that if an event is chosen it'll always pick it in the following messages, unless the sampling percentage was reduced.
• No extra metadata to add in every message you send, nor receive.
• No need for communications between systems to sample/pick the same events/sessions.
• Tested in real world scenarios, against millions of events.

Why i made this library?

I needed it to build a tracing system that samples a complete session/flow, to gain visibility on a data pipeline that receives events/messages with a single key/id identifying a complete session.

Documentation

GoDoc

License

BSD 3-Clause License

Copyright (c) 2017, Khalid Lafi
All rights reserved.

Redistribution and use in source and binary forms, with or without
modification, are permitted provided that the following conditions are met:

* Redistributions of source code must retain the above copyright notice, this
  list of conditions and the following disclaimer.

* Redistributions in binary form must reproduce the above copyright notice,
  this list of conditions and the following disclaimer in the documentation
  and/or other materials provided with the distribution.

* Neither the name of the copyright holder nor the names of its
  contributors may be used to endorse or promote products derived from
  this software without specific prior written permission.

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