https://github.com/observatorium/observable-demo

Demo of the instrumented L7 HTTP loadbalancer in Go following best practices.
https://github.com/observatorium/observable-demo

best-practices demo instrumentation loadbalancer metrics prometheus

Last synced: 4 months ago
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Demo of the instrumented L7 HTTP loadbalancer in Go following best practices.

• Host: GitHub
• URL: https://github.com/observatorium/observable-demo
• Owner: observatorium
• License: apache-2.0
• Created: 2020-01-09T11:01:57.000Z (over 6 years ago)
• Default Branch: master
• Last Pushed: 2020-01-26T10:33:22.000Z (over 6 years ago)
• Last Synced: 2024-06-21T06:42:07.017Z (almost 2 years ago)
• Topics: best-practices, demo, instrumentation, loadbalancer, metrics, prometheus
• Language: Go
• Homepage:
• Size: 73.2 KB
• Stars: 7
• Watchers: 2
• Forks: 1
• Open Issues: 0
• Metadata Files:
  • Readme: README.md
  • License: LICENSE

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README

          
# observable-demo

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This repository includes simple L7 round robin loadbalancer implementation, instrumented with metrics.

> `WARNING` : This is not meant to be production ready L7 loadbalancer. It's missing things like proper retrying, DNS discovery, logging, tracing etc, that might be added in future (:



This implementation was **mainly** used for presentations that showcase best practices for Prometheus based metrics Go instrumentation like:

* [Avoiding globals](https://github.com/observatorium/observable-demo/blob/e89e67a9e3e564d1ab3cb716835c8969f4bc1201/pkg/lbtransport/transport.go#L31).

* [Middlewares](https://github.com/observatorium/observable-demo/blob/e89e67a9e3e564d1ab3cb716835c8969f4bc1201/pkg/exthttp/middleware.go#L82) and [Tripperwares](https://github.com/observatorium/observable-demo/blob/d9cf53a171f4b016512337faa3e36411830525df/pkg/exthttp/tripperware.go#L46).

* Histograms [usage](https://github.com/observatorium/observable-demo/blob/e89e67a9e3e564d1ab3cb716835c8969f4bc1201/pkg/lbtransport/transport.go#L43).

* [Avoiding high cardinality](https://github.com/observatorium/observable-demo/blob/e89e67a9e3e564d1ab3cb716835c8969f4bc1201/pkg/lbtransport/transport.go#L42).

* [Initialising metrics](https://github.com/observatorium/observable-demo/blob/e89e67a9e3e564d1ab3cb716835c8969f4bc1201/pkg/lbtransport/transport.go#L62).

* [Wrapping registries](https://github.com/observatorium/observable-demo/blob/e89e67a9e3e564d1ab3cb716835c8969f4bc1201/pkg/exthttp/middleware.go#L84).

* Naming conventions

* [Testing metrics](https://github.com/observatorium/observable-demo/blob/d9cf53a171f4b016512337faa3e36411830525df/pkg/lbtransport/transport_test.go#L189)

## Using demo

This demo is runable.

To run loadbalancer and Prometheus in docker run:

``` console

make demo

```

After this, you should be able to go via browser to:

* `http://localhost:8080/lb` for load balancing endpoint, that loadbalanced to 3 fake endpoints.

* `http://localhost:8080/metrics` for metric page

* `http://localhost:9090` for Prometheus UI that scrapes loadbalancer every second.

To curl loadbalancer every 500ms to generate traffic run in separate terminal:

``` console

make demo-test

```