DiffusionData Releases Diffusion 6.12

DiffusionData, the pioneer and leader in real-time data streaming, today announced the release of Diffusion 6.12. The latest enhancements have been introduced to speed up development, optimize resource usage, and guarantee consistent, high-performance real-time data delivery.

Grethe Brown, CEO of DiffusionData, said: “As a company, we’ve always been driven by the insights of our community, ensuring our solution directly aligns with client needs. By listening closely to evolving requirements, we’ve introduced enhancements to our framework that addresses real-world developer challenges while boosting operational efficiency. These improvements are designed to accelerate productivity, reduce complexity, and create tangible business value. The ongoing feedback from our customers fuels continuous innovation in Diffusion, enabling our clients to deliver better outcomes and stay competitive.”

Enhancements in Diffusion 6.12 include:

Enhancements to the ‘Set’ Operation in Topic Views
The ‘set’ operation within the Topic Views process clause has been enhanced to support additional use cases and provide greater flexibility when shaping output data. Key improvements include:

Ability to Clear Output Structures
Output structures (objects, arrays, or even the root) can now be emptied prior to selectively copying required items into the output. This simplifies scenarios where large input datasets need to be reduced to only a few items. New special values are available: empty_object and empty array (or, for short, $O and $A respectively). For example, set(, $O) clears the entire output, while set(/pointer, $O) clears only a specific structure.

Copying Items to the Same Output Location
A new “set to pointer” capability allows items (scalars or structures) to be copied directly to the same pointer location in the output. This is particularly useful when repopulating a structure that was previously cleared.

Support for Copying Complete Data Structures
This enhancement enables copying of entire objects or arrays in addition to scalar values, making it possible to move complete structures from input to output which is useful if a higher-level structure has been cleared, but also allows for copying to entirely different structures.

Metric Alerts
There is a new Metrics notifications feature which allows metrics alerts to be notified to topics when certain criteria are satisfied. For example, an alert could be set up which will write to a topic when the memory utilisation exceeds a specified threshold.

Session Authentication – Expiry
There is now a new session property called “$ExpiryTime” which lets an authenticator define when a session should automatically close, in milliseconds. If not set, the session won’t expire. Clients can now use the new re-authenticate method – replacing changePrincipal – to either switch principals or re-authenticate with the same one, while also updating session properties if needed. Clients can check their own fixed session properties, including expiry time, with getSessionProperties. Finally, administrators can use revokeAuthentication to immediately close another client’s session.

Put together, these changes mean that sessions now have clearer lifecycles. They can expire automatically, be refreshed by re-authentication, and be forcibly revoked by administrators when necessary.

Topic View insert ’s now Allowed at any Point in the Specification
Topic view inserts can now appear anywhere in the specification, not just at the end, allowing them to be interspersed with other transformations.

Regular Expression Matching for String Comparison in Topic Views
There is now a new matches or =~ operator available in topic view “process” conditionals. This allows for advanced string comparisons using regular expressions, providing greater flexibility and precision.

Session Lock Query API
There is now a new API available in the ClientControl feature, which enables control clients to query session locks. There is a getSessionLocks method, which returns details of all current session locks, as well as a getSessionLock method to query a specific named session lock.

SubscriptionControl Feature now Cluster Aware
Previously, the SubscriptionControl feature methods to subscribe and unsubscribe sessions would only work for sessions connected to the same server as the control client using the feature. This meant that when Diffusion was running in a cluster a control client would need to connect separately to all servers in the cluster in order to manage all sessions. In this release, all methods in the SubscriptionControl feature apply to all sessions across a cluster.

SELECT_TOPIC Permissions Changes
In 6.12, the SELECT_TOPIC path permission is required for all paths that a topic selector may match — not just the path prefix. In earlier versions, SELECT_TOPIC permission was only required for the prefix of a topic selector. A session could use a selector to access an entire branch of the topic tree as long as it had permission at the top-level path. As a result, it was not possible to selectively remove access from a sub-branch — access to the parent path implicitly granted access to everything below it.

The permission model has now been made more restrictive. To fetch or subscribe using a topic selector, a session must now have SELECT_TOPIC permission for each individual path that the selector may match. This allows SELECT_TOPIC to be granted to a branch of the topic tree and explicitly revoked for specific sub-branches.
For full path pattern topic selectors, the model is even more restrictive: SELECT_TOPIC permission is required for all paths at and below the path prefix. This is necessary to prevent circumvention using advanced regular expressions. This enhancement delivers more granular, flexible, and secure topic access management.

Improvements to the Journal Feature
In 6.12, the Journal feature has been simplified. The feature is now configured in the Server.xml configuration file, and the issued file contains a sample block with the feature disabled. A sample configuration file is now issued in the Diffusion ./etc installation directory which has all possible actions that can be configured, but with all disabled.

Topic Selection Scopes
In previous versions of Diffusion, if two different components of a client application, sharing a single Diffusion connection, subscribed to a topic and one of them later unsubscribed, the topic would be unsubscribed for the session and consequently for all components. Now, it is possible to specify a named scope when subscribing, such that a later unsubscription specifying that scope has no effect on other subscriptions that named a different scope. This allows subscriptions to be localised to the components that need them. There are now new subscription and unsubscription methods that take a scope parameter to support this. Applications using the old methods will continue to work as before, as their subscriptions will all be assigned to a default scope.

Other Improvements

1. In 6.12, both the Diffusion server and Java Client require Java 17. Older clients can still connect, but the 6.12 Java Client is needed to access all new features.
2. The JavaScript Client and Console now support the Safari browser.
3. The Dotnet SDK client can now specify a custom URL path to connect to Diffusion through use of the new parameterless ISessionFactory Open and OpenAsync API in conjunction with the new ISessionFactory attributes: ServerHost , ServerPort , SecureTransport and RequestPath .