Title:     Information and Data Registry
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Airavata provides capabilities for an integrated workflow and data management system. The information and data has to
be persisted into a registry service. To adhere to the philosophies of Airavata for layering over existing stable third
party components, Airavata usage is consolidated into a thick-client API. This API allows the pluggability of the
infrastructure and avoids locks in into any specific registry architectures. This following figure summarizes the use
of the registry.

![Airavata Registry Usage](/architecture/airavata-registry.png "Airavata Registry Usage")

## JCR Specification:
The Content Repository for Java Technology specification, developed under the Java Community Process JSR-170, aims to
standardize Java API to repositories. The specification provides a unified API under the javax.jcr namespace that allows
you to access any specification-compliant repository implementation in a vendor-neutral manner. A major advantage of
JSR-170 is that it is not tied to any particular underlying architecture. The back-end data storage for a JSR-170
implementation, for instance, may be a filesystem, a WebDAV repository, an XML-backed system, or even an SQL database.
Furthermore, the export and import facilities of JSR-170 allow an integrator to switch seamlessly between content
back ends and JCR implementations. Finally, the JCR provides a straightforward interface that can be layered on top of
a wide variety of existing content repositories, while simultaneously standardizing complex functionality such as
versioning, access control, and searching. There are open source implementations of JSR-170 such as Apache Jackrabbit,
Alfresco and WSO2 Registry.

##Airavata Registry API
When implementing registry functionality to store data and retrieve data we did not want to have locking for any custom
API's to content repository implementations. Airavata tried to integrate with existing repositories without having to
re-invent the wheel. JCR-2.0 specification and the JSR-170 implementation is plugged in to Apache Airavata system. The
Airavata specific API layers over the generic JCR API and is integrated with Apache Jackrabbit implementation. The API
is modularized as a common component reused by XBaya and GFac components to store and retrieve data. In addition to the
service information, the registry is used to catalog workflow consumed inputs and generated output data. The registry
is also used to advertise and retrieve persistent service information. The use of the registry for GFac service
registration allows for late service binding and supporting large number of applications provided by the inherent
load balance capabilities. For more up to date information and samples on Airavata API, refer
[Client API Overview][api].

[api]: https://cwiki.apache.org/confluence/display/AIRAVATA/Client+API+Overview