Heroku Labs: Application Metrics Beta Channel
Last updated 21 January 2017
An opt-in labs channel is available for the Dashboard Metrics, which allows users to preview and comment on upcoming features.
How to opt in
To opt into the beta using the Dashboard, navigate to the Dashboard Metrics page.
To opt in from the Heroku CLI type:
$ heroku labs:enable metrics-beta
How to opt out
To opt out of the beta using the Dashboard, click the link beside the Labs Features button in the Metrics UI.
To opt out using the Heroku CLI type:
$ heroku labs:disable metrics-beta
Individual beta features are enabled and disabled through the Lab Features dialog. Note that not all beta features will be available to all dyno types upon release to general audience. If there are additional features you would like to see let us know.
Data lag indicator
To help differentiate between application outages and missing metrics data we’ve released a beta feature that highlights data gaps.
Autoscaling is currently available only for Performance-tier dynos and dynos running in Private Spaces. Autoscaling lets you scale your web dyno quantity up and down automatically based on your app’s current request latency.
Threshold autoscaling is configured from your app’s Resources tab on the Heroku Dashboard:
Click the Enable Autoscaling button next to your web dyno details. The Threshold Autoscaling configuration options appear:
Use the slider or text boxes to specify your app’s allowed autoscaling range. The minimum cannot be less than
1 and the maximum cannot be less than your current dyno count. The cost range associated with the specified autoscaling range is shown directly below the slider. Your dyno count is never scaled to a quantity outside the autoscaling range you specify.
Next, set your app’s Desired p95 Response Time. The autoscaling engine uses this value to determine how to scale your dyno count. A recommended p95 response time is provided.
Enable Email Notifications if you’d like all app collaborators (or org members if you’re using Heroku Teams/Organizations) to be notified when your web dyno count reaches the specified upper limit. At most one notification email is sent per day.
The dyno manager uses your app’s Desired p95 Response Time to determine when to scale your app. The autoscaling algorithm uses data from the past hour to calculate the minimum number of web dynos necessary to achieve the desired response time for 95% of incoming requests adjusted for the current request throughput. Every time an autoscaling event occurs, a single web dyno is added or removed from your app. Autoscaling events are always at least 1 minute apart. Scaling down was designed to be slightly less responsive to prevent a situation where aggressive downscaling for a brief lull in requests results in request timeouts if the demand subsequently spikes upward.
Monitoring autoscale events
Autoscaling events appear alongside manual scale events in the Events chart. In event details they are currently identified as having been initiated by “Dyno Autoscaling”. In addition, enabling, disabling and changes to autoscaling are shown.
If you disable autoscaling the dyno count will remain at its current setting.
Known issues & limitations
As with any autoscaling utility there are also certain application health scenarios in which autoscaling may not not help. You may also need to tune your Postgres connection pool to accommodate changes in dyno formation. We strongly recommend that you simulate the production experience with load testing, and use Threshold Alerting in conjunction with Threshold Autoscaling to monitor end user experience.
Response time summary
Similar to the memory summary, this feature displays summary metrics for response time, including the average of the median response times and the average of the 95th percentile median response times for the selected time interval.
7-Day data retention
7-day retention provides metrics for the past seven days at 2 hour retention, displayed on a single plot.
You can provide feedback through the Labs Feature dialog or by emailing the Dashboard Metrics team directly at firstname.lastname@example.org. Please drop us a line and let us know what you think.