Lifecycle Query Engine

You can use indexed data from Lifecycle Query Engine (LQE) data sources to report on artifacts across projects or versioned data in configurations.

Lifecycle Query Engine is a Jazz™ application that is registered with a single Jazz Team Server. In a distributed environment, friend relationships can be set up across different servers, providing access to the application data.

You can use LQE with either the default Apache Derby database or with an external database; what you choose depends on how you deploy LQE. For example, if you deploy a single LQE node, you can use either option. However, if you are deploying LQE across several nodes, you must use an external database.

Important: Lifecycle Query Engine is the data source for reporting on projects with or without configurations; however, there are considerations. See this article on Jazz.net about reporting on data in configurations.

What is an LQE index and how does it work?

Lifecycle tools make data available for indexing by using tracked resource sets (TRS); members of the TRS are retrievable resources with resource description framework (RDF) representations, called index resources. You can create and run SPARQL queries on the RDF data set that aggregates the RDF graphs of the index resources. These queries include data from across the lifecycle tools; they also include cross-tool links between the resources. The change log in the tracked resource set captures any changes that happen to index resources, and the changes are propagated to the lifecycle index, keeping it up to date.

Resources in a TRS can be protected resources. An LQE administrator can grant access to indexed resources based on the entire index, each data source that is indexed, or access contexts that are defined by the lifecycle tools.

For more information about the TRS specification, see Open Services for Lifecycle Collaboration Tracked Resource Set Specification Version 2.0 .

How long does it take to index data?

If you are creating an index for the first time, or reindexing data, the process can take some time to complete. The duration of the data indexing process is difficult to define. If the lifecycle tools are working perfectly, then the duration depends on the amount of data to be indexed by LQE. If the amount of data is very small, indexing might take a few minutes or an hour. If there is a large volume of data, indexing might take several days. The duration also depends on the hardware configurations.

Indexing speed is also affected by issues that the tools might encounter, such as socket timeouts, TRS feeds that are slow, and slow fetching of resources. These issues can result in skipped resources. For more information, see Managing data sources for Lifecycle Query Engine.

When LQE is indexing a data source, you can see information about the progress and gauge how long indexing might take. The progress indicator shows the number of resources to be indexed. Because LQEdoes not know how much data is available from each of the data sources, when you start indexing, the reported number of resources might not be accurate. However, as indexing continues, LQE looks ahead at the TRS base and over time the progress indicator reflects a more accurate count.

LQE administrators can receive email notifications for data source events by configuring the associated properties. See Setting up email notification for Lifecycle Query Engine events.

Technology preview: LQE with property graph technology

Starting in version 6.0.6, you can use a new LQE solution in your test environments for evaluation purposes. By using property graph technology, the new LQE solution offers elastic scalability for growing data and user base.
Attention: Do not use the technology preview on production servers or with large repositories. For detailed information, read this article on Jazz.net.

Terminology used by LQE

Resource
A resource is an object that is described by RDF expressions. An RDF resource is identified by a URI.
For more information, see Composite Capabilities/Preference Profiles: Terminology and Abbreviations
Triple
An RDF triple contains three components; the Subject, the Predicate, and the Object.
For more information, see Resource Description Framework (RDF): Concepts and Abstract Syntax
Graph
An RDF graph is a set of RDF triples.
For more information, see Resource Description Framework (RDF): Concepts and Abstract Syntax
RDF vocabulary
An RDF vocabulary describes the meaningful use of properties and classes in RDF data.
For more information, see RDF Vocabulary Description Language 1.0: RDF Schema

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