Analytics events

Overview

This topic explains analytics events, how SDKs send them to LaunchDarkly, and what features they are generated for.

Server-side, client-side, and edge SDKs send analytics events to LaunchDarkly as a result of feature flag evaluations and certain SDK calls. There are several kinds of analytics events.

Here is a list of analytics event kinds and their functions:

• summary events describe a set of individual feature evaluations over an interval.
• feature events include additional feature flag evaluation details for flags used in Experimentation and flags you enable detailed tracking for.
• debug events describe feature flag evaluations when debugging mode is on.
• migration_op events describe metrics collected as part of reading and writing migration flags.
• index and identify events push context data to LaunchDarkly.
• page view and click events are sent by JavaScript-based SDKs when pages are visited or clicked as part of an experiment.
• custom events are sent when an application calls the SDK's track method.

Analytics events are crucial to the functioning of several features in LaunchDarkly.

Here is a list of LaunchDarkly features that rely on analytics events:

• The Contexts list
• Target with flags
• Flag statuses and lifecycle stages
• Live events
• Data Export
• Experimentation
• Migration flag metrics

Event buffering and sending

LaunchDarkly SDKs automatically send pending analytics events to LaunchDarkly at regular intervals. This is called a flush interval. The buffer between flushes prevents the SDK from having to send constant network requests, and varies by SDK. By default, server-side SDK buffer time is usually a few seconds, and mobile SDK buffer time is around 30 seconds. A longer buffer time for mobile SDKs helps preserve the device's battery life, and events do not need to be flushed as often because events build up much more slowly for client-side SDKs with only a small number of contexts.

You can configure your SDK's buffer time between flushes.

Manually flush events

You can manually call flush to send events immediately without waiting for the next interval. Most customers do not need to use the manual flush feature, but it can be useful if you test the SDK in a simulator.

Shut down your SDK

You do not need to manually shut down your SDK in most situations. However, if your app dies while there are still events in the buffer, the SDK discards them. If you know your application is about to terminate, or if you're testing an app, you should manually shut down the LaunchDarkly client before quitting to ensure it delivers any pending analytics events to LaunchDarkly.

Omit anonymous contexts from events

By default, index and identify events push context data to LaunchDarkly. In some server-side SDKs, you can configure the SDK to omit data from anonymous contexts when sending these index and identify events. Depending on how your application uses contexts, this can significantly decrease the amount of data your application sends to LaunchDarkly.

Include prerequisite information in events

Any client-side SDK that is configured to send events sends a combination of summary, debug, and feature events back to LaunchDarkly for each evaluated flag.

Additionally, most client-side SDKs also send the same combination of summary, debug, and feature events back to LaunchDarkly for any flags that are prerequisites of the flag explicitly being evaluated. Sending events for prerequisite flags is required for some LaunchDarkly features, such as holdouts. To find which client-side SDKs support sending events for prerequisite flags, read Supported features.

Most server-side SDKs return metadata on flag prerequisites as part of the all flags feature. To find which server-side SDKs support including prerequisite information as part of all flags, read Supported features.

Disable SDKs from sending events

You can disable SDKs from sending events for testing purposes. To learn more, read Manage test data in your production environment.