go-load-tester

go-load-tester is a distributed load testing framework. It is based on Vegeta and can run in a distributed mode (something that Vegeta cannot do at the moment), borrowing the approach from Locust.

NOTE: this is a work in progress.

Known limitations:

• The framework is currently Sentry-oriented. The data generators that are currently supported are described here.
• Worker registration/keep-alive behaviour is not very robust

Usage

For supported load generators and parameter details -- see here.

More information about the general architecture and writing tests.

The load tester can run in a few modes:

• as a master process controlling worker load testers
• as a worker load tester
• as a standalone load tester ( this is achieved by running it in worker mode without providing a master url)

Global usage

Usage:
  go-load-tester [command]

Available Commands:
  completion  Generate the autocompletion script for the specified shell
  help        Help about any command
  run         Runs the load tester
  update-docs Extract docs from source code into static files.

Flags:
      --color           Use color (only for console output).
      --config string   configuration directory (default ".config")
      --log string      Log level: trace, info, warn, (error), fatal, panic (default "info")

Use "go-load-tester [command] --help" for more information about a command.

Running Load Tester

Usage:
  go-load-tester run [command]

Available Commands:
  master      Run load tester in master mode.
  worker      Run a worker, that waits for commands from a server

Flags:
  -h, --help                   help for run
  -p, --port string            port to listen to (default "8000")
      --statsd-server string   ip:port for the statsd server
  -t, --target-url string      target URL for the attack
  -w, --workers int            threads to use to build load (default 10)

Global Flags:
      --color           Use color (only for console output).
      --config string   configuration directory (default ".config")
      --log string      Log level: trace, info, warn, (error), fatal, panic (default "info")

Use "go-load-tester run [command] --help" for more information about a command.

Master Mode

NOTE: When running the load tester in master mode the server also exposes a documentation page under the /docs url ( i.e. http(s)://<SERVER_ADDRESS:PORT>/docs)

Usage:
  go-load-tester run master [flags]

Global Flags:
      --color                  Use color (only for console output).
      --config string          configuration directory (default ".config")
      --log string             Log level: trace, info, warn, (error), fatal, panic (default "info")
  -p, --port string            port to listen to (default "8000")
      --statsd-server string   ip:port for the statsd server
  -t, --target-url string      target URL for the attack

Worker Mode and Standalone Mode

For running the load tester in standalone mode do not provide the master-url parameter

Usage:
  go-load-tester run worker [flags]

Flags:
  -m, --master-url string   Registers worker with the specified master

Global Flags:
      --color                  Use color (only for console output).
      --config string          configuration directory (default ".config")
      --log string             Log level: trace, info, warn, (error), fatal, panic (default "info")
  -p, --port string            port to listen to (default "8000")
      --statsd-server string   ip:port for the statsd server
  -t, --target-url string      target URL for the attack

Parallelism

The worker takes -w parameters that defines the level of parallelism used to produce the requests for the target. This allows us to have a request ready as soon as it is needed even when high volume is needed.

It is important to set this parameter accurately specifically when the worker runs in an environment where the number of cores is limited (like k8s) or when it takes long to produce each requests (like large batches of data).

Some tips to find the right value assuming the process to generate the request is CPU intensive:

1. If you are only limited by the number of cores on your machine, just set the parallelism value to the number of cores.

2. If you have more specific limits (like when running in k8s), estimate or measure the time it takes to produce a request. You can try by setting w to 1 and messages per second to 1 then increase this last one. Either you saturate the system you are testing first, or you reach a point where you cannot produce faster.

   * If you saturate the target first, you do not have a problem in producing
   

   requests.

   * If you saturate the producer first you know how many requests per second you
   

   can produce from this test. The parallelism you want is the desired number of request per second divided by the request per second per thread.