Artemis

Artemis is a library which dynamically resize the amount of workers (goroutines) to run functions in parallel at your target rate.

Installation

$ go get -u github.com/RY-2718/artemis

Usage

package main

import (
	"context"
	"fmt"
	"runtime"
	"time"

	"github.com/RY-2718/artemis"
)

func main() {
	// Define the function to run
	f := func() {
		time.Sleep(300 * time.Millisecond)
	}
	
	// Define the rate (frequency, error rate)
	rate := artemis.Rate{
		Freq:      100,
		Per:       time.Second, // Set `Per` param as time.Second now
		ErrorRate: 0.1,
	}

	ctx := context.Background()
	// Runner has responsibility for running function and reporting stats
	runner := artemis.Runner{}

	go runner.RunWithRate(ctx, &rate, f)

    // If you want to report periodically, using Ticker is a solution
	ticker := time.NewTicker(1 * time.Second)
	for {
		select {
		case <-ticker.C:
			// runner.Report() returns a struct which have RPS (rate per second), TargetRPS
			r := runner.Report()
			fmt.Printf("%f, %f, %d\n", r.RPS, r.TargetRPS, runtime.NumGoroutine())
		}
	}
}

Performance

Here we show the performance of Artemis at [100, 1000] rps (rate per second).

Artemis increases workers exponentially at first, and decreases them by half when rps exceeds target rps, then increases again when rps gets below the target.

License

MIT