go_app

ASATS test app

This app is used in the app-autoscaler acceptance test suite (ASATS) to generate metrics to test end-to-end scenarios.

The app can be made to consume and release on demand:

• main memory
• CPU
• hard disk

It can be used to emit custom metrics.

It can be used to respond to HTTP requests:

• as fast as possible
• or with a configurable request latency

The API of the test app is not part of the public API and may change at any time.

Still, the app can be useful during development and one such use case is described in detail in the next section.

Deploy Test Application with Custom Metrics

Sample Autoscaling Policy

Autoscaling policy is available at test-policy.json

{
  "instance_min_count": 1,
  "instance_max_count": 2,
  "scaling_rules": [
    {
      "metric_type": "review_count",
      "breach_duration_secs": 60,
      "threshold": 200,
      "operator": ">=",
      "cool_down_secs": 60,
      "adjustment": "+1"
    },
    {
      "metric_type": "review_count",
      "breach_duration_secs": 60,
      "threshold": 100,
      "operator": "<=",
      "cool_down_secs": 60,
      "adjustment": "-1"
    }
  ]
}

Deploy Test Application

Prepare acceptance_config.json. Example acceptance_config.json

CONFIG=$PWD/acceptance_config.json make deploy-test-app && \
#attach autoscaling policy (as defined above)
cf attach-autoscaling-policy test_app test-policy.json && \
# show autoscaling policy using autoscaler cli plugin
cf asp test_app

Send Custom Metrics

# scale out 
APP_ROUTE=$(cf app test_app | grep routes | awk '{print $2}')
curl https://$APP_ROUTE/custom-metrics/mtls/review_count/201

# scale In 
APP_ROUTE=$(cf app test_app | grep routes | awk '{print $2}')
curl https://$APP_ROUTE/custom-metrics/mtls/review_count/78

View Metrics in Log Cache

Metrics are ingested into log-cache and can be viewed using CF Log Cache CLI Plugin

cf tail --name-filter="review_count" test_app --follow