Metrics Demo

Usage

• Install dependencies: make
• Be aware that composer is configured to ignore file system changes. You must run make each time you create, move, rename or delete files in src.
• Start the containers: docker-compose up -d
• Watch the client using the app: docker-compose logs -f client
• Open Grafana http://localhost:3000 (credentials = admin/admin)
• add data source (Configuration -> Data Sources -> Add Data Source): URL = http://influxdb:8086, db = metrics
• add dashboard (New Dashboard -> Import Dashboard -> Upload .json file) from docker/grafana/dashboards
• Scale client application to 10, 20, 40 instances and watch the changes on the dashboard: make scale-up clients=10 (make scale-down for downgrading the load back to 1 client again)
• watch all the containers live with ctop:

docker run -it --name ctop --rm -v /var/run/docker.sock:/var/run/docker.sock wrfly/ctop:latest

Application

ToDo list manager

See test/support/todo.http.

• Registration
• Login
• Get all lists
• Get one list
• Create list
• Delete list
• Get tasks
• Create task
• Mark task as done
• Mark task as not done
• Delete task

TODO: Instrumentation

• HTTP response status metrics
• Response time metrics
• Business metrics (total/minute):
  • registrations
  • logins
  • created lists
  • created tasks
  • done tasks

Degradation scenarios

1. Decrease/increase number of clients.
2. Decrease/increase wait time between client actions.
3. Decrease/increase number of php-fpm workers.
4. Decrease/increase size of nginx connection pool.
5. Drop/add mysql index.
6. Flush redis.
7. Decrease curl connection timeout on client.
8. Decrease curl operation timeout on client.
9. Add sleep in server index.php.