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

Get them here.

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

$ go get github.com/masahide/vegeta-mysql
$ go install github.com/masahide/vegeta-mysql

Usage: vegeta [global flags] <command> [command flags]

global flags:
  -cpus int
        Number of CPUs to use (default 24)
  -profile string
        Enable profiling of [cpu, heap]
  -version
        Print version and exit

attack command:
  -body string
        Requests body file
  -dsn string
        Data Source Name has a common format (default "password@protocol(address)/dbname?param=value")
  -duration duration
        Duration of the test (default 10s)
  -maxIdleConns int
        Max open idle connections per target host (default 10000)
  -maxOpenConns int
        Max open connections per target host (default 10000)
  -output string
        Output file (default "stdout")
  -rate uint
        Requests per second (default 50)
  -timeout duration
        Requests timeout (default 30s)
  -workers uint
        Initial number of workers (default 10)

report command:
  -inputs string
        Input files (comma separated) (default "stdin")
  -output string
        Output file (default "stdout")
  -reporter string
        Reporter [text, json, plot, hist[buckets]] (default "text")

dump command:
  -dumper string
        Dumper [json, csv] (default "json")
  -inputs string
        Input files (comma separated) (default "stdin")
  -output string
        Output file (default "stdout")

examples:
  vegeta-mysql attack -dsn "user:pass@tcp(localhost:3306)/hostname" -body sql.txt -duration=60s | tee results.bin | vegeta-mysql report
  vegeta-mysql report -inputs=results.bin -reporter=json > metrics.json
  cat results.bin | vegeta-mysql report -reporter=plot > plot.html
  cat results.bin | vegeta-mysql report -reporter="hist[0,100ms,200ms,300ms]"

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

Usage of vegeta-mysql attack:
  -body string
        Requests body file
  -dsn string
        Data Source Name has a common format (default "password@protocol(address)/dbname?param=value")
  -duration duration
        Duration of the test (default 10s)
  -maxIdleConns int
        Max open idle connections per target host (default 10000)
  -maxOpenConns int
        Max open connections per target host (default 10000)
  -output string
        Output file (default "stdout")
  -rate uint
        Requests per second (default 50)
  -timeout duration
        Requests timeout (default 30s)
  -workers uint
        Initial number of workers (default 10)

sql text.

Specifies the timeout for each request. The default is 0 which disables timeouts.

Specifies the initial number of workers used in the attack. The actual number of workers will increase if necessary in order to sustain the requested rate.

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

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.

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

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

Requests      [total, rate]             1200, 120.00
Duration      [total, attack, wait]     10.094965987s, 9.949883921s, 145.082066ms
Latencies     [mean, 50, 95, 99, max]   113.172398ms, 108.272568ms, 140.18235ms, 247.771566ms, 264.815246ms
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

{
  "latencies": {
    "total": 237119463,
    "mean": 2371194,
    "50th": 2854306,
    "95th": 3478629,
    "99th": 3530000,
    "max": 3660505
  },
  "bytes_in": {
    "total": 606700,
    "mean": 6067
  },
  "bytes_out": {
    "total": 0,
    "mean": 0
  },
  "earliest": "2015-09-19T14:45:50.645818631+02:00",
  "latest": "2015-09-19T14:45:51.635818575+02:00",
  "end": "2015-09-19T14:45:51.639325797+02:00",
  "duration": 989999944,
  "wait": 3507222,
  "requests": 100,
  "rate": 101.01010672380401,
  "success": 1,
  "status_codes": {
    "200": 100
  },
  "errors": []
}

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).

Each point on the plot shows a request, the X axis represents the time at the start of the request and the Y axis represents the time taken to complete that request.

Computes and prints a text based histogram for the given buckets. Each bucket upper bound is non-inclusive.

cat results.bin | vegeta report -reporter='hist[0,2ms,4ms,6ms]'
Bucket         #     %       Histogram
[0,     2ms]   6007  32.65%  ########################
[2ms,   4ms]   5505  29.92%  ######################
[4ms,   6ms]   2117  11.51%  ########
[6ms,   +Inf]  4771  25.93%  ###################

$ vegeta dump -h
Usage of vegeta dump:
  -dumper="": Dumper [json, csv]
  -inputs="stdin": Input files (comma separated)
  -output="stdout": Output file

Specifies the input files containing attack results to be dumped. You can specify more than one (comma separated).

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

Specifies the dump format.

Dumps attack results as JSON objects.

Dumps attack results as CSV records with six columns. The columns are: unix timestamp in ns since epoch, http status code, request latency in ns, bytes out, bytes in, and lastly the error.

Whenever your load test can't be conducted due to Vegeta hitting machine limits such as open files, memory, CPU or network bandwidth, it's a good idea to use Vegeta in a distributed manner.

In a hypothetical scenario where the desired attack rate is 60k requests per second, let's assume we have 3 machines with vegeta installed.

Make sure open file descriptor and process limits are set to a high number for your user on each machine using the ulimit command.

We're ready to start the attack. All we need to do is to divide the intended rate by the number of machines, and use that number on each attack. Here we'll use pdsh for orchestration.

$ pdsh -b -w '10.0.1.1,10.0.2.1,10.0.3.1' \
    'echo "GET http://target/" | vegeta attack -rate=20000 -duration=60s > result.bin'

After the previous command finishes, we can gather the result files to use on our report.

$ for machine in "10.0.1.1 10.0.2.1 10.0.3.1"; do
    scp $machine:~/result.bin $machine.bin &
  done

The report command accepts multiple result files in a comma separated list. It'll read and sort them by timestamp before generating reports.

$ vegeta report -inputs="10.0.1.1.bin,10.0.2.1.bin,10.0.3.1.bin"
Requests      [total, rate]         3600000, 60000.00
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]               100.0%
Status Codes  [code:count]          200:3600000
Error Set:

package main

import (
  "fmt"
  "time"

  vegeta "github.com/masahide/vegeta/lib"
)

func main() {
  rate := uint64(100) // per second
  duration := 4 * time.Second
  targeter := vegeta.NewStaticTargeter(vegeta.Target{
    Method: "GET",
    URL:    "http://localhost:9100/",
  })
  attacker := vegeta.NewAttacker()

  var metrics vegeta.Metrics
  for res := range attacker.Attack(targeter, rate, duration) {
    metrics.Add(res)
  }
  metrics.Close()

  fmt.Printf("99th percentile: %s\n", metrics.Latencies.P99)
}

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.

The MIT License (MIT)

Copyright (c) 2013-2015 Tomás Senart

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