Process Federation Server components overview

Terminology

The terms federated system or federated instance can refer to either an IBM Business Process Manager or a Business Automation Workflow server that is part of the federated environment.

Architecture

Process Federation Server provides end users with a unified view of tasks, process instances and case instances running on different Business Automation Workflow and Case Manager federated systems.

REST APIs

Indexers and retrievers

For each federated system to configure, two components must be configured: an indexer and a retriever.

Indexers

The indexer inserts JSON documents that describe all the instances and/or tasks that run on the federated system into a Federated Data Repository index. Each federated system has its own single index, and depending on the version and on the type (BPD, BPEL or Case) of the system that you want to federate, the indexer runs either on Process Federation Server or on Business Automation Workflow nodes.

Process and BPEL indexers:

• constantly poll the federated system’s database to identify which tasks and process instances must be indexed into the Federated Data Repository.
• perform SQL queries to the database to build the document that will be indexed into Elasticsearch for each identified task and process instance.
• perform maintenance operations on the database tables involved in the indexing.
• in Business Automation Workflow 24.0.0.0, the process indexer was redesigned and is now configured and runs on the Business Automation Workflow federated system. For older process versions and for BPEL, the indexer is still configured and runs as part of Process Federation Server.

The Case indexer indexes Case instances into the Federated Data Repository.

• To federate a system hosting process instances and tasks, you must define the indexer either in Process Federation Server or in Business Automation Workflow, depending on your version of Business Automation Workflow:
  • For Business Automation Workflow 24.0.0.0, there is no indexer to configure in Process Federation Server. Instead, Business Automation Workflow must be configured to index directly in the Federated Data Repository as documented in Configuring Business Automation Workflow to index to the Federated Data Repository.
  • For Business Automation Workflow 23.0.2 and earlier, you must configure the indexer in the Process Federation Server configuration through an <ibmPfs_bpdIndexer> element. For more details, see Enabling indexing of process-related data in a federated environment.
    Note: Federating a Business Automation Workflow 24.0.0.0 process system by configuring the <ibmPfs_bpdIndexer> element in Process Federation Server configuration is deprecated. However, you can upgrade your Business Automation Workflow federated system to 24.0.0.0 as usual, and then disable the indexer in Process Federation Server to replace it with the new Federated Data Repository process indexing as documented in Enabling the Federated Data Repository process indexing.
• To federate a system hosting BPEL process instances and tasks, you must configure the indexer in Process Federation Server configuration through a <ibmPfs_bpelIndexer> element. For more details, see Enabling indexing of BPEL-related data in a federated environment.
• To federate a Case Manager system, you must configure the indexer in Case Manager configuration as described in Indexing case instances.

Retrievers

Retrievers perform requests to the federated systems, and store into the Federated Data Repository cache data such as:

• the system status
• the list of launchable entities
• the teams memberships of users

The retriever is always configured as part of Process Federation Server:

• To federate the BPMN (BPD) process instances and tasks hosted by a Business Automation Workflow system, you must configure the retriever through a <ibmPfs_bpdRetriever> element. For more details, see The ibmPfs_bpdRetriever element.
• To federate the BPEL process instances and tasks hosted by a Business Automation Workflow system, you must configure the retriever through a <ibmPfs_bpelRetriever> element. For more details, see The ibmPfs_bpelRetriever element.
• To federate a Case Manager system, you must configure the retriever through a <ibmPfs_caseRetriever> element. For more information, see The ibmPfs_caseRetriever element.

External components