Diffusion releases and versioning

The version selector at the top of this site relates to a supported version of the core Diffusion Server product. Selecting a version number will update all relevant hyperlinks across the site, to reference documentation at an appropriate matching or compatible version.

Key points

• The Diffusion Server is versioned using a three part major.minor.patch numbering format but does not follow strict semantic versioning (see notes below).
• Diffusion SDK versions are aligned with that of the Diffusion Server.
• Other libraries (e.g. adapters, gateway framework, MCP server) are versioned independently of the Diffusion Server, and as such may be released at different times. (They may retain a dependency upon a particular Diffusion Server version.)
• Each version of Diffusion is supported for at least 18 months. After this, a version may be declared end-of-life once there have been three subsequent major or minor releases.
• Support for earlier versions falling outside of this window is available through extended support contracts.

Release cadence

We have a general release cadence of one new minor release per year, although this is not fixed and minor releases may be more frequent. Patch releases may occur throughout the same period, on any of the three currently supported major.minor versions.

We recommend customers always upgrade to the latest available patch version of the release that they are using.

Notes on compatibility and upgrade paths

Major version upgrades are generally not API compatible and will introduce breaking changes. We endeavor to maintain compatibility between the 'terminal' release of the previous major release, and the new major release through a documented upgrade path, which will involve code changes.

Minor version upgrades may also occasionally introduce breaking changes by removing deprecated functionality. This is not compatible with strict semantic versioning. However, functionality will never be removed without prior notice of deprecation in at least one previous minor release. This will be provided in release notes, as well as in API documentation where the language permits.

Each Diffusion Server release provides compatibility with:

• Diffusion client libraries from the same release
• Diffusion client libraries from earlier supported releases with the same major version
• Diffusion client libraries from the 'terminal' release of the previous major release

...with the possibility of feature deprecation in the latter two cases.

This compatibility model is designed to support an upgrade path where Diffusion Server instances are upgraded first, and the client libraries can then be upgraded as customer app release requirements permit.

Specific notes on the Diffusion management console (web UI)

The Diffusion management console provides a web-based interface for monitoring and configuration of running Diffusion Server instances. It will connect to a running server by supplied URL.

A console instance is provided within the installer for each Diffusion Server release, and once running, the console can be instructed to connect to any running Diffusion server - not necessarily matching the version through which it was delivered.

Considerations:

• An older version of the console will maintain compatibility with later versions of the Diffusion Server
• A later version of the console may rely upon API features that are not implemented by an older Diffusion Server release
• However, we endeavour to maintain backwards compatibility in the second scenario, although some console features may be unavailable or restricted

Support and upgrade policy

Full details are published here, including a list of active and end-of-life release versions.