Vegeta

Vegeta is a versatile HTTP load testing tool built out of need to drill HTTP services with a constant request rate. It can be used both as a command line utility and a library.

Install

Pre-compiled executables

• Mac OSX 64 bit
• Mac OSX 32 bit
• Linux 64 bit
• Linux 32 bit

Source

You need go installed and GOBIN in your PATH. Once that is done, run the command:

$ go get github.com/tsenart/vegeta
$ go install github.com/tsenart/vegeta

Usage examples

$ echo "GET http://localhost/" | vegeta attack -rate=100 -duration=5s | vegeta report
$ vegeta attack -targets=targets.txt > results.vr
$ vegeta report -input=results.vr -reporter=json > metrics.json
$ cat results.vr | vegeta report -reporter=plot > plot.html

Usage manual

$ vegeta -h
Usage: vegeta [globals] <command> [options]

Commands:
  attack  Hit the targets
  report  Report the results

Globals:
  -cpus=8 Number of CPUs to use

-cpus

Specifies the number of CPUs to be used internally. It defaults to the amount of CPUs available in the system.

attack

$ vegeta attack -h
Usage of attack:
  -duration=10s: Duration of the test
  -header=: Targets request header
  -ordering="random": Attack ordering [sequential, random]
  -output="stdout": Output file
  -rate=50: Requests per second
  -targets="stdin": Targets file

-duration

Specifies the amount of time to issue request to the targets. The internal concurrency structure's setup has this value as a variable. The actual run time of the test can be longer than specified due to the responses delay.

-header

Specifies a request header to be used in all targets defined. You can specify as many as needed by repeating the flag.

-ordering

Specifies the ordering of target attack. The default is random and it will randomly pick one of the targets per request without ever choosing that target again. The other option is sequential and it does what you would expect it to do.

-output

Specifies the output file to which the binary results will be written to. Made to be piped to the report command input. Defaults to stdout.

-rate

Specifies the requests per second rate to issue against the targets. The actual request rate can vary slightly due to things like garbage collection, but overall it should stay very close to the specified.

-targets

Specifies the attack targets in a line sepated file, defaulting to stdin. The format should be as follows.

GET http://goku:9090/path/to/dragon?item=balls
GET http://user:password@goku:9090/path/to
HEAD http://goku:9090/path/to/success
...

report

$ vegeta report -h
Usage of report:
  -input="stdin": Input files (comma separated)
  -output="stdout": Output file
  -reporter="text": Reporter [text, json, plot]

-input

Specifies the input files to generate the report of, defaulting to stdin. These are the output of vegeta attack. You can specify more than one (comma separated) and they will be merged and sorted before being used by the reports.

-output

Specifies the output file to which the report will be written to.

-reporter

Specifies the kind of report to be generated. It defaults to text.

text

Requests      [total]               1200
Latencies     [mean, 95, 99, max]   223.340085ms, 326.913687ms, 416.537743ms, 7.788103259s
Bytes In      [total, mean]         3714690, 3095.57
Bytes Out     [total, mean]         0, 0.00
Success       [ratio]               55.42%
Status Codes  [code:count]          0:535  200:665
Error Set:
Get http://localhost:6060: dial tcp 127.0.0.1:6060: connection refused
Get http://localhost:6060: read tcp 127.0.0.1:6060: connection reset by peer
Get http://localhost:6060: dial tcp 127.0.0.1:6060: connection reset by peer
Get http://localhost:6060: write tcp 127.0.0.1:6060: broken pipe
Get http://localhost:6060: net/http: transport closed before response was received
Get http://localhost:6060: http: can't write HTTP request on broken connection

json

{
  "latencies": {
    "mean": 9093653647,
    "95th": 12553709381,
    "99th": 12604629125,
    "max": 12604629125
  },
  "bytes_in": {
    "total": 782040,
    "mean": 651.7
  },
  "bytes_out": {
    "total": 0,
    "mean": 0
  },
  "requests": 1200,
  "success": 0.11666666666666667,
  "status_codes": {
    "0": 1060,
    "200": 140
  },
  "errors": [
    "Get http://localhost:6060: dial tcp 127.0.0.1:6060: operation timed out"
  ]
}

plot

Generates an HTML5 page with an interactive plot based on Dygraphs. Click and drag to select a region to zoom into. Double click to zoom out. Input a different number on the bottom left corner input field to change the moving average window size (in data points).

Usage (Library)

package main

import (
  vegeta "github.com/tsenart/vegeta/lib"
  "time"
  "fmt"
)

func main() {
  targets, _ := vegeta.NewTargets([]string{"GET http://localhost:9100/"})
  rate := uint64(100) // per second
  duration := 4 * time.Second

  results := vegeta.Attack(targets, rate, duration)
  metrics := vegeta.NewMetrics(results)

  fmt.Printf("Mean latency: %s", metrics.Latencies.Mean)
}

Limitations

There will be an upper bound of the supported rate which varies on the machine being used. You could be CPU bound (unlikely), memory bound (more likely) or have system resource limits being reached which ought to be tuned for the process execution. The important limits for us are file descriptors and processes. On a UNIX system you can get and set the current soft-limit values for a user.

$ ulimit -n # file descriptors
2560
$ ulimit -u # processes / threads
709

Just pass a new number as the argument to change it.

Licence

The MIT License (MIT)

Copyright (c) 2013 Tomás Senart

Permission is hereby granted, free of charge, to any person obtaining a copy of
this software and associated documentation files (the "Software"), to deal in
the Software without restriction, including without limitation the rights to
use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of
the Software, and to permit persons to whom the Software is furnished to do so,
subject to the following conditions:

The above copyright notice and this permission notice shall be included in all
copies or substantial portions of the Software.

THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS
FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR
COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER
IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.