Data saving mode
Data saving mode is available for Early Access
Data saving mode is supported in the SDKs listed below. It is also supported in the Relay Proxy.
Data saving mode is only available to members of LaunchDarkly’s Early Access Program (EAP). If you want access to this feature, join the EAP.
This topic explains how data saving mode works in the LaunchDarkly SDKs that support it, listed below. The Relay Proxy also supports data saving mode.
Server-side SDKs in data saving mode first open a polling connection to LaunchDarkly. The initial payload from this connection contains the data the SDK will need to operate and perform flag evaluations.
Subsequently, server-side SDKs in data saving mode open a streaming connection and receive realtime flag configuration changes over the stream. These configuration changes include only the difference between the server-side SDK’s stored configuration and the latest configuration in LaunchDarkly. The SDKs use in-memory data for the unchanged aspects of the flag configuration.
The SDKs fall back to using a polling connection if LaunchDarkly streaming is unavailable. Data saving mode includes additional configuration options that let you set a backup data source, enabling automatic failover if a connection is unavailable.
Depending on the number of flags in your project and the complexity of their configuration, data saving mode can significantly improve performance, including reducing your network costs when in polling mode or on reconnection. Additionally, SDKs in data saving mode have reduced memory and CPU usage overall.
Track service connection usage by application
When using data saving mode, you can track which applications are consuming service connections by configuring application metadata. Set the applicationId in your SDK configuration to see a per-application breakdown on the Service connections usage page under the SDK App ID dimension. Server-side streaming connections without applicationId configured appear as “Unknown.” To learn how, read Application metadata configuration.
Server-side SDKs
This feature is available in the following SDKs:
.NET (server-side)
Expand .NET (server-side) SDK code sample
To enable data saving mode:
- If you are using the Relay Proxy, upgrade your Relay Proxy to version 9.0.0-rc.1 or later.
- Upgrade your .NET (server-side) SDK to version 8.11 or later.
- Update your SDK configuration to enable the
DataSystemconfiguration option.
Here’s how to enable the DataSystem configuration option:
Standard setup
We recommend the standard data system configuration for most customers. It uses a combination of streaming and polling to initialize the SDK, provide real time updates, and switch between streaming and polling automatically to provide redundancy.
Relay proxy with LaunchDarkly API fallback
File-based bootstrap with live updates
To learn more, read DataSystemModes for information about pre-configured data system modes, and DataSystemBuilder for information on additional configuration options.
Go
Expand Go SDK code sample
To enable data saving mode:
- If you are using the Relay Proxy, upgrade your Relay Proxy to version 9.0.0-rc.1 or later.
- Upgrade your Go SDK to version 7.11 or later.
- Update your SDK configuration to enable the
DataSystemconfiguration option.
Here’s how to enable the DataSystem configuration option:
Standard setup
We recommend the standard data system configuration for most customers. It uses a combination of streaming and polling to initialize the SDK, provide real time updates, and switch between streaming and polling automatically to provide redundancy.
Relay proxy with LaunchDarkly API fallback
File-based bootstrap with live updates
To learn more, read DataSystem. For information on additional configuration options, read DataSystemConfiguration.
Java
Expand Java SDK code sample
To enable data saving mode:
- If you are using the Relay Proxy, upgrade your Relay Proxy to version 9.0.0-rc.1 or later.
- Upgrade your Java (server-side) SDK to version 7.11 or later.
- Update your SDK configuration to enable the
dataSystemconfiguration option.
Here’s how to enable the dataSystem configuration option:
Standard setup
We recommend the default data system configuration for most customers. It uses a combination of streaming and polling to initialize the SDK, provide real time updates, and switch between streaming and polling automatically to provide redundancy.
Relay proxy with LaunchDarkly API fallback
File-based bootstrap with live updates
To learn more, read DataSystemModesfor information about pre-configured data system modes, and DataSystemBuilder for information on additional configuration options.
Node.js (server-side)
Expand Node.js (server-side) code sample
To enable data saving mode:
- If you are using the Relay Proxy, upgrade your Relay Proxy to version 9.0.0-rc.1 or later.
- Upgrade your Node.js (server-side) SDK to version 9.10 or later.
- Update your SDK configuration:
- Enable the
dataSystemconfiguration option. - Migrate existing
LDOptionsfields. The following existing options were previously top-levelLDOptionsfields and are part of thedataSystemconfiguration as of version 9.10:persistentStore,stream,streamInitialReconnectDelay,pollInterval,useLDD.
- Enable the
Here’s how to enable the dataSystem configuration option:
Standard setup
We recommend the standard data source option for most customers. It uses a combination of streaming and polling to initialize the SDK, provide real time updates, and switch between streaming and polling automatically to provide redundancy.
File-based bootstrap with live updates
To learn more, read dataSystem. For information on additional configuration options, read LDDataSystemOptions.
Python
Expand Python SDK code sample
To enable data saving mode:
- If you are using the Relay Proxy, upgrade your Relay Proxy to version 9.0.0-rc.1 or later.
- Upgrade your Python SDK to version 9.13 or later.
- Update your SDK configuration to enable the
DataSystemconfiguration option.
Here’s how to enable the DataSystem configuration option:
Standard setup
We recommend the standard data system configuration for most customers. It uses a combination of streaming and polling to initialize the SDK, provide real time updates, and switch between streaming and polling automatically to provide redundancy.
Relay proxy with LaunchDarkly API fallback
File-based bootstrap with live updates
To learn more, read ldclient.datasystem. For information on additional configuration options, read DataSystemConfig.
Ruby
Expand Ruby SDK code sample
To enable data saving mode:
- If you are using the Relay Proxy, upgrade your Relay Proxy to version 9.0.0-rc.1 or later.
- Upgrade your Ruby SDK to version 8.12.0 or later.
- Update your SDK configuration to enable the
data_system_configconfiguration option.
Here’s how to enable the data_system_config configuration option:
Standard setup
We recommend the standard data system configuration for most customers. It uses a combination of streaming and polling to initialize the SDK, provide real time updates, and switch between streaming and polling automatically to provide redundancy.
Relay proxy with LaunchDarkly API fallback
File-based bootstrap with live updates
To learn more, read LaunchDarkly::DataSystem. To learn more about additional configuration options, read DataSystem::ConfigBuilder.
Client-side SDKs
Client-side SDKs in data saving mode use the same data system pipeline as server-side SDKs, adapted to the lifecycle and connectivity characteristics of the client environment. SDKs may switch between connection modes automatically in response to application lifecycle events and network state changes. Some client-side SDKs use streaming when the application is active or in the foreground for real-time flag updates, and switch to polling or reduce activity when the application is backgrounded or hidden.
This feature is available in the following SDKs:
Android
Expand Android SDK code sample
Consider mobile update tails before shipping EAP code
Mobile applications have long update tails. Apps you ship today may remain installed on end-user devices for years. If you include the EAP version of the Android Client SDK in a production release, the EAP-era API surface and behaviors may persist in deployed apps long after data saving mode graduates to General Availability. Make sure your release timeline can tolerate shipping a non-stable API.
To enable data saving mode:
- Upgrade your Android Client SDK to version 5.13 or later.
- Request to join the Early Access Program. Wait to receive confirmation from LaunchDarkly that data saving mode is enabled for your account.
- Update your SDK configuration to enable the
dataSystemconfiguration option.
Here’s how to enable the dataSystem configuration option:
Standard setup
We recommend the standard data system configuration for most customers. It uses a combination of streaming and polling to initialize the SDK, provide real time updates, and switch between streaming and polling automatically to provide redundancy.
Automatic mode switching
The Android Client SDK switches between connection modes automatically based on app lifecycle and network connectivity. You can disable automatic switching entirely, or selectively disable lifecycle-driven or network-driven switching.
To disable automatic switching entirely and keep the SDK in a single connection mode regardless of lifecycle or network changes:
To disable lifecycle-driven switching but continue switching modes when network connectivity changes:
To learn more, read Components.dataSystem(). To learn more about additional configuration options, read DataSystemBuilder.
JavaScript
Expand JavaScript SDK code sample
To enable data saving mode:
- Upgrade your JavaScript SDK to version 4.9 or later.
- Request to join the Early Access Program. Wait to receive confirmation from LaunchDarkly that data saving mode is enabled for your account.
- Update your SDK configuration to enable the
dataSystemconfiguration option.
Here’s how to enable the dataSystem configuration option:
Standard setup
We recommend the standard data system configuration for most customers. The JavaScript SDK opens a streaming connection for real-time flag updates, and falls back to polling when streaming is unavailable.
Set a fixed connection mode
To keep the SDK in a single connection mode instead of letting it manage the connection, use manual mode switching and set the initial connection mode:
To learn more, read LDOptions.dataSystem.
React Native
Expand React Native SDK code sample
Consider mobile update tails before shipping EAP code
Mobile applications have long update tails. Apps you ship today may remain installed on end-user devices for years. If you include the EAP version of the React Native SDK in a production release, the EAP-era API surface and behaviors may persist in deployed apps long after data saving mode graduates to General Availability. Make sure your release timeline can tolerate shipping a non-stable API.
To enable data saving mode:
- Upgrade your React Native SDK to version 10.19 or later.
- Request to join the Early Access Program. Wait to receive confirmation from LaunchDarkly that data saving mode is enabled for your account.
- Update your SDK configuration to enable the
dataSystemconfiguration option.
Here’s how to enable the dataSystem configuration option:
Standard setup
We recommend the standard data system configuration for most customers. The React Native SDK uses streaming in the foreground for real-time flag updates and polling in the background, and switches between connection modes automatically as the app moves between the foreground and background.
Automatic mode switching
By default, the React Native SDK switches between connection modes automatically based on app lifecycle. To disable automatic switching entirely and keep the SDK in a single connection mode regardless of lifecycle changes:
To learn more, read LDOptions.dataSystem.
React Web
Expand React Web SDK code sample
The React Web SDK is built on the JavaScript SDK, so it supports the same dataSystem configuration. Pass the option through the provider’s ldOptions.
To enable data saving mode:
- Upgrade your React Web SDK to version 4.2 or later.
- Request to join the Early Access Program. Wait to receive confirmation from LaunchDarkly that data saving mode is enabled for your account.
- Update your SDK configuration to enable the
dataSystemconfiguration option.
Here’s how to enable the dataSystem configuration option:
Standard setup
We recommend the standard data system configuration for most customers. The React Web SDK opens a streaming connection for real-time flag updates, and falls back to polling when streaming is unavailable.
Set a fixed connection mode
To keep the SDK in a single connection mode instead of letting it manage the connection, use manual mode switching and set the initial connection mode:
To learn more, read LDReactClientOptions.