What’s new in Mender: Server-side generation of delta updates

The latest Mender Server 4.1 LTS release introduces production-grade server-side generation of delta updates.

Server-side generation of delta updates

Delta updates can save significant network costs in bandwidth-sensitive environments, such as metered cellular networks. Delta updates can also greatly reduce issues where devices are unable to download a full update completely due to unreliable networks. Depending on the environment, delta updates can reduce the download size by up to 95%, transferring only the difference between the currently installed software and the one to be deployed.

The challenge with leveraging delta updates effectively is the inherent interdependence – which delta is needed depends on which software the device is currently running. In turn, delta updates potentially create a complex version matrix to be managed.

With server-side generation of delta updates in Mender, this device-specific delta generation is automatically and transparently solved by the Mender Server. For a given deployment, delta updates can be enabled under Advanced options.

The status of the delta update generation can be monitored under both Deployments (indicating that a delta is being generated for a Device) and a new tab under Releases.

As an optional step, optimizing the delta generation to the smallest possible size depends on the Artifact being deployed and the changes made between the releases. These parameters can now be set in Global settings in the Mender UI.

Please note: Server generation of delta updates currently supports “rootfs-image” type of updates (full A/B file system updates). This update type is typically the largest type of update, and the devices need to be configured with a read-only file system. See more information in the documentation. Future releases will support more update types for server-generation.

For the full list of Mender enhancements, check out the changelogs for Mender Server.

Try the new features

The hosted deployment of Mender is already updated with all the new features. If you’re an existing customer, check out the new features and functionality in your account today!

Note: Server-side generation of delta updates is only available with the Enterprise plan.

For self-hosted, on-premise Mender, please refer to the Server upgrade documentation to get the latest release.

If you are new to Mender, we recommend following the Get started documentation and signing up for a Free Trial account. No credit card is required, and you get 10 devices for free for 12 months.

Share your feedback

We hope these changes will simplify and help Mender users going forward. Share your feedback about the new Mender features and suggestions for future improvements in the Mender Hub General Discussions forum. If you encounter any issues with the new release, please report them in the Mender JIRA issue tracker with detailed reproduction steps and system information, or use Mender support if you are a Mender customer.