prom-loadtest-metrics-generator

README

Prometheus scrape endpoint generator

Application to be run as part of a Prometheus load test which exposes multiple target endpoints for Prometheus to scrape.

Endpoints are provided at /metrics/<endpoint_number> for example /metrics/2. The metrics returned include a range of counters, gauges and histograms with random values.

This tool is designed to be used in conjunction with the load test tool and the Prometheus terraform repo.

It is based off the Prometheus prombench fake-webserver and has been adapted to make it easier to generate the necessary metrics and size of time series needed for load testing at a number of different loads.

Configuration

• ENDPOINT_COUNT - The number of endpoints to expose from /metrics/1 to /metrics/<ENDPOINT_COUNT>
• ROUTE_COUNT - The number of routes for our pretend application on which the metrics are based (roughly 1 route equates to 60 metrics)
• SCRAPE_INTERVAL - The scrape interval in seconds for Prometheus of your targets

Pre-requisites

You will need to install Go lang

Running the webserver

Make a copy of environment_sample.sh to environment.sh file and source it - source environment.sh.

Execute ./run_app.sh -w on a terminal to run the webserver locally.

Deploying the server to PaaS

Update the manifest.yml to set your desired ENDPOINT_COUNT and ROUTE_COUNT.

Run cf push in the sandbox space.

Set up your Prometheus to scrape your load test endpoints

Execute ./run_app.sh -c on a terminal to create the scrape config section for your new targets. It will look similar to:

- job_name: load-test-targets-1
  metrics_path: "/metrics/1"
  scheme: https
  scrape_interval: 30s
  static_configs:
  - targets: ["prom-loadtest-metrics-generator.cloudapps.digital"]
- job_name: load-test-targets-2
  metrics_path: "/metrics/2"
  scheme: https
  scrape_interval: 30s
  static_configs:
  - targets: ["prom-loadtest-metrics-generator.cloudapps.digital"]

You should then append this to the config file for your development Prometheus stack at terraform/app-ecs-services/templates/prometheus.tpl.