Understanding LaunchDarkly metrics

Overview

This guide explains the different kinds of LaunchDarkly metrics and what you can use them for. LaunchDarkly uses different kinds of metrics to do things like measure flag change impact, gauge application performance, track account usage, and more.

The five kinds of metrics within LaunchDarkly include:

• Flag impact metrics
• Engineering insights project metrics
• Migration flag metrics
• Application adoption metrics
• Account metrics

Continue reading to learn more about each kind of metric and how you can use metrics to help meet your business needs throughout the software development, deployment, and release cycle.

How to find the right metric for your needs

Most LaunchDarkly capabilities that use metrics automatically include metrics as part of the feature. Engineering insights, migration flags, applications, and account usage all include metrics ready for you to use. Flag impact metrics are different in that they require you to do some initial metric setup before you can use them. You can read more about flag impact metrics in the next section.

If you're confused about which metric to use for a particular business purpose, use the LaunchDarkly docs site search function to search for "metric + [use]". For example, you might search for "metric deployment" for documentation on engineering insights metrics, or "metric migration" for migration flag metrics.

If you still are unsure what metric to use for your needs after reading this guide, start a Support ticket.

Flag impact metrics

Flag impact metrics measure changes in audience or system behaviors affected by flag variations. Flag impact metrics are unique from other LaunchDarkly metrics in that there are no pre-defined metrics. You must first create and define what you want a metric to measure before you can use it. You can then use the metric with flags and experiments.

Flag impact metrics can measure things like:

• how often customers access a URL
• how long a URL takes to load a page
• how often customer payments succeed
• how many items customers purchase per transaction
• how long it takes for a server to respond to a request
• how long until the time to first byte

There are five types of flag impact metrics: clicked or tapped conversion, custom conversion binary, custom conversion count, custom numeric, and page viewed conversion metrics. For examples of what each type of flag impact metric can measure, read Creating and managing metrics.

LaunchDarkly records metric data through metric events. You can export metric event information to other applications to perform analysis in third-party tools. For a full list of available metric integrations, read Experimentation and metric integrations.

You can also import metric events from third-party applications to use with LaunchDarkly. To learn how, read Importing metric events.

You can use flag impact metrics as part of Experimentation and guarded rollouts.

Experimentation

Experimentation lets you track single metrics or metric groups on multiple variations of the same flag to find out which performs best over time. When you have enough data from your Experimentation metrics to make a decision, you can then roll out the winning variation to the rest of your audience. To learn more, read Experimentation.

Guarded rollouts

Guarded rollouts let you attach single metrics or metric groups to a targeting rule on a flag.

If those metrics detect regressions, or negative impact, after you start serving the flag variation, LaunchDarkly can notify you or automatically roll back the flag change. To learn more, read Guarded rollouts.

Engineering insights project metrics

Engineering insights is a set of features within LaunchDarkly. Engineering insights lets you track key engineering metrics in one place to improve engineering efficiency and assess team performance. To learn more, read Engineering insights.

Engineering insights project metrics include:

• Deployment frequency and deployment failure rate: these metrics measure how often you deploy code and how often you have to roll back those deployments. This helps you understand the productivity of your engineering teams. To lean more, read Deployments.
• Releases and flag impact: these metrics measure the number and size of impactful flag changes your team makes over time. This helps you understand how and when impactful changes are going out to your customers. To learn more, read Releases.
• Lead time: this metric measures the time between first code commit and successful deployment to an environment. This helps you understand the efficiency of your engineering teams. To learn more, read Lead time.
• Flag health: this metric measures the ratio of stale flags to total temporary flags in your environment. This helps you understand if you need to be more proactive in archiving and removing stale flags from your code. To learn more, read Flag health.
• Experimentation coverage: this metric measures measures the number of your flag changes that are associated with an experiment. This helps you understand if you are running a sufficient number of experiments on your flag changes. To learn more, read Experimentation coverage.

Migration flag metrics

A migration feature flag is a temporary flag you can use to migrate data or systems while keeping your application available and disruption free. Migration flags break the transition from an old to a new implementation into a series of two to six stages. You can use migration flag metrics to track the progress of a migration flag. To learn more, read Migration flags.

Migration flag metrics include:

• consistency rate: this metric shows how often two sets of compared data match each other
• p99 latency: this metric measures custom latency rates as reported by your SDK
• error rate: this metric measures errors as reported by your SDK

To learn more, read Migration flag metrics.

You can configure migration flag metrics in your SDK. To learn more, read Migration configuration.

Application adoption metrics

When you are developing a mobile app, you can use applications to track version adoption and to evaluate flags differently for supported or unsupported app versions. To learn more, read Applications and application versions.

You can use application adoption metrics to understand the adoption percentage for an application version. To learn more, read Adoption metrics.

Account metrics

You can use account metrics to understand your client-side monthly active users (MAU) usage, Experimentation key usage, Data Export usage, and server usage for billing purposes. To learn more, read Account usage metrics.

Conclusion

LaunchDarkly provides a variety of metrics to provide you with the information you need to make informed business decisions. For more help deciding which metrics to use for your needs, start a Support ticket.