Published Release Notes

Updated architecture of the data flow service

Benefit from improvements to data flow architecture that increase the stability of data flow runs and minimize the need for manual restarting of data flow jobs. Real-time data flows now use improved node rebalancing for better handling of failed or restarted nodes. If the topology changes, batch data flows no longer attempt to pause and resume the run. As such, there are fewer interactions with the database and between the nodes, resulting in the increased resilience of the Data Flow service.

If you are upgrading from a previous version of Pega Platform™, see Changes to the architecture of the Data Flow service for an overview of the changes to the Data Flow service compared to previous versions.

Changes to the architecture of the Data Flow service

In Pega Platform™ 8.4, the architecture of batch and real-time data flows uses improved node handling to increase the stability of data flow runs. As a result, there are fewer interactions with the database and between the nodes, resulting in increased resilience of the Data Flow service.

If you upgrade from a previous version of Pega Plaftorm, see the following list for an overview of the changes in the behavior of the Data Flow service compared to previous versions:

• Responsiveness
• Updates to lifecycle actions
• Starting a run
• Triggering pre- and post-activities
• Selecting a node fail policy
• No service nodes and active runs

Responsiveness

Nodes no longer communicate and trigger each other, but run periodic tasks instead. As such, triggering a new run does not cause the service nodes to immediately start the run. Instead, the run starts a few seconds later. The same applies to user actions such as stopping, starting, and updating the run. The system also processes topology changes as periodic tasks, so it might take a few minutes for new nodes to join runs, or for partitions to redistribute when a node leaves a run.

Updates to lifecycle actions

To make lifecycle actions more intuitive, the Stop action consolidates both the Stop and Pause actions. The Start action consolidates both the Resume and Start actions.

You can resume or restart stopped and failed runs with the Start and Restart actions. The Start action is only available for resumable runs and continues the run from where it stopped. The Restart action causes the run to process from the beginning. Completed runs can only be restarted. If a run completes with failures, you can restart it from the beginning, or process only the errors by using the Reprocess failures action.

Starting a run

New data flow runs have the Initializing status, and start automatically. You no longer need to manually start a new run, so the New status is now removed.

If there are no nodes available to process a run, the run gets the Queued status and waits for an available node.

Triggering pre- and post-activities

The system now triggers pre-activities on a random service node, rather than on the node that triggered the run.

The system triggers post-activities only for runs that complete, fail, or complete with failures. If you manually stop a run with the Stop action, the post-activity does not trigger. However, restarting the run with the Restart action triggers first the post-activity, and then the pre-activity.

You can no longer choose to run pre- and post-activities on all nodes.

Selecting a node fail policy

For resumable runs, you can no longer select a node fail policy. If a node fails, the partitions assigned to that node automatically continue the run on different nodes.

For non-resumable runs, you can choose to restart the partitions assigned to the failed node on different nodes, or to fail the partitions assigned to the failed node.

No service nodes and active runs

If the last data flow node for an in-progress run fails, the run remains in the In Progress state, even if no processing takes place. This behavior results from the fact that data flow architecture now prevents unrelated nodes from affecting runs.

Support for predictive models in PMML version 4.4

Pega Platform™ now supports the import of predictive models in Predictive Model Markup Language (PMML) version 4.4. With this feature, you can import PMML models that use the anomaly detection algorithm.

For a list of all supported PMML models, see Supported models for import. 

Low-code styling in mobile apps

The mobile channel now supports enhanced low-code styling and branding of mobile apps. For example, you can customize app icons in three different ways: by uploading an image, by selecting from a list of font icons, or by using the default text-based icons. This enhancement helps you to conveniently customize the look of mobile apps to match the branding guidelines of your company and provide a consistent experience for users across different channels.

For more information, see Applying a custom theme to mobile apps.

Offline support for Cosmos-based mobile apps

Mobile apps that are based on the Cosmos design system now support offline mode. Previously, offline-enabled apps had to rely on the classic look. Now, you can use the low-code Cosmos solutions to design apps that operate reliably regardless of the connection status. 

For more information, see Designing apps for offline mode.

Removal of Pega Mobile Client 7

You can now use a single Pega Mobile Client™ that improves app performance, app development, and meets all your mobile needs. With the introduction of new functionalities for mobile apps, Pega Mobile Client 7 is removed in Pega Platform™ 8.5.

Upgrade impact

After an upgrade to Pega 8.5, you can no longer build mobile apps based on Pega Mobile Client 7, and existing apps based on Pega Mobile Client 7 no longer connect to Pega Platform. App developers can now configure mobile apps with Pega Mobile Client.

What steps are required to update the application to be compatible with this change?

Existing clients that upgrade to Pega 8.5 are automatically switched to Pega Mobile Client.

Limits on active data flow runs

You can now configure a maximum number of concurrent active data flow runs for a node type. Set limits to ensure that you do not run out of system resources and that you have a reasonable processing throughput. If a limit is reached, the system queues subsequent runs and waits for active runs to stop or finish before queued runs can be initiated, starting with the oldest.

For more information see, Limit the number of active runs in data flow services (8.5).

Upgrade impact

If you have many data flow runs active at the same time, you might notice that some of the runs are queued and waiting to be executed.

What steps are required to update the application to be compatible with this change?

You do not have to take any action. After the active runs stop or finish, the queued runs start automatically. The default limits are intended to protect your system resources, and you should not see a negative impact on the processing of data flows. However, if you want to allow a greater number of active data flow runs to be active at the same time, you can change the limits. For more information, see Limiting active data flow runs.

Support for Apache HBase 2.1 and Hadoop 3.0

Support for these versions extends Pega Platform™ compatibility with HBase releases to ensure that your database implementations integrate seamlessly with Pega Platform.

Pega Platform now supports:

• Apache HBase 2.1 for the HBase data set
• Apache Hadoop Distributed File System (HDFS) 3.0 for the HDFS data set

For more information, see Enhance your data sets with Apache HBase 2.1 and Hadoop 3.0 (8.5).

Web portal reuse removed from the mobile channel

The reuse of web portals for creating mobile apps with a single web view is no longer supported. You can conveniently update your existing channels that reuse web portals to take advantage of the multiple-views experience and native mobile capabilities, such as native mobile list views or floating action buttons.

Upgrade impact

The Reuse web portal option is removed from Pega Platform 8.5 and later.

What steps are required to update the application to be compatible with this change?

App developers need to use the migration tool available on the mobile channel to move their apps to the recommended new navigation designer. When users open existing mobile channel with the Reuse web portal option configured, they are prompted to run through the wizard to upgrade the mobile channel to the latest Pega Mobile Client based configuration. When this is done, app developers should rebuild the app.

Enhanced search in the mobile channel

The search configuration now includes up to three additional secondary fields, such as the case ID, category, cost, date, owner, and active channel. The enhancement increases the usability of search on mobile apps and provides more contextual information in the search results.

For more information, see Adding a search gadget.