Openwings Specification Request (OSR)

Title:

Openwings Real-time Data Distribution Service (OSR_014)

Summary:

The Expert Team focuses on providing a high-performance and real-time data distribution service. The service promotes autonomous software components that use the service as a normalized interaction environment to share properly modeled and distributed system data.

Section 1. Identification

Submitting Member and Specification Lead:

	Submitting Member	Specification Lead
Name of Contact	Hans van ‘t Hag	Hans van ‘t Hag
Telephone Number	31-74-2483683	31-74-2483683
Fax Number	31-74-2484018	31-74-2484018

Expert Nominee Qualifications:

The desired qualifications for this expert team are:

Experienced with large-scale distributed systems
Experienced with real-time and embedded systems
Experienced with data-modeling techniques
Experienced with Openwings connector technologies
Experienced with network protocol stacks (reliable multicast)
Experienced with SQL and embedded-SQL
Understanding of data-flow oriented systems
Understanding of model-based systems

Section 2: Request

2.1 Please describe the proposed Specification:

The proposed specification describes a service that supports high-performance and real-time access to selectively replicated information in the data-flow oriented parts of an Openwings based distributed system. As such, the service adds the ‘information centric’ paradigm of offering ‘the right information at the right place at the right time’ to the already available service-centric features of Openwings. This ‘webtone for information’ as provided by the service strongly promotes autonomous components with real-time behavior and adds a new level to ‘easy’, ‘dynamic’, ‘de-coupled’ and ‘adaptive’.

The specification will address all lifecycle phases in the following way:

a. system design	: specification of an information model including data-classification (QoS)
b. system development	: intuitive set of simple yet powerful API’s that leverage from database-expertise
c. system integration	: visibility of information (data & meta-data) using API’s and support-tools
d. system deployment	: QoS enforced by the service regarding delivery, persistency and urgency
e. system maintenance	: evolutionary upgrading of both the information-model and applications

The Expert team will be responsible for developing the following:

Service Specification
Reference Implementation
Compatibility Test Suite

2.2 What is the target Java platform? (i.e., desktop, server, personal, embedded, card, etc.)

J2SE is largely targeted towards desktop and webtop applications on the front end. J2EE is largely targeted towards E-Commerce and back end servers. J2ME is targeted towards the device market. This specification has a system focus on information distribution between networked components, which includes the front end, back end, and devices; hence this specification targets all three Java platforms.

2.3 What need of the Openwings community will be addressed by the proposed specification?

There are several applications that require access to reliable, real-time information. Military applications would include ISR processing systems and real-time targeting. Commercial applications would include robotics, factory automation and tightly coupled control systems.

2.4 Why isn't this need met by existing specifications?

The proposed specification would provide mechanism for high speed, data dissemination with real-time, highly available data stores with deterministic response times. It will also provide capabilities for Quality of Service, prioritization and data replication for critical information. The closest relevant specifications are the Data Services Specification (an Openwings Facility) and the Connector Specifications (part of Openwings Core).

The existing Data Services specification focuses on persisting objects transparently in a 3-tier architecture. This proposed specification will focus on providing critical information elements to multiple destinations on the network in real-time and will provide a high-performance mechanism for persistence storage and data access. Examples of where this type of real-time data distribution is required are Robotics (i.e. Factory Automation), control systems and real-time targeting applications.

Part of this capability will require real-time dissemination of data. It is the intent to evaluate the existing connector architecture in terms of suitability for real-time data distribution. As a result of this analysis, we may either propose changes to the connector architecture or propose a real-time connector as part of this specification.

2.5 Please give a short description of the underlying technology or technologies:

This specification will make use the following technologies: Internet Protocol Version 6 (Ipv6), UDP, Real-Time JVM, Openwings Connectors, Real-time networking extensions, and SQL.

2.6 Is there a proposed package name for the API Specification? (i.e., javapi.something, org.something, etc.)

The proposed package for this specification is net.openwings.facilities.r2d2.

2.7 Does the proposed specification have any dependencies on specific operating systems, CPUs, or I/O devices that you know of?

This specification may have a dependency on IPv6.

2.8 Are there any security issues that cannot be addressed by the current Openwings security model?

No.

2.9 Are there any internationalization or localization issues?

This OSR is targeted towards systems that may be internationally deployed and hence use the internationalization features of Java. It is anticipated that the existing internationalization infrastructure will be sufficient for this OSR.

2.10 Are there any existing specifications that might be rendered obsolete, deprecated, or in need of revision as a result of this work?

Potential changes to the Connector specification may be proposed as a result of this work.

2.11 Please describe the anticipated schedule for the development of this specification.

The following schedule applies:

Milestone	Date
Openwings Specification Request Approved	Sept 2001
Form Expert Group	Oct 2001
Participant Draft	TBD– 4Q 2001
Participant Review	TBD– 1Q 2002
Public Review	TBD– 1Q 2002
Beta Release	TBD– 2Q 2002
Maintenance	TBD

Once the expert team is formed the finalized schedule will be made available.

Section 3: Contributions

3.1 Please list any existing documents, specifications, or implementations that describe the technology.

Thales has previously generated material that is being contributed as a basis for this OSR. In particular the following contributions available at http://www.openwings.org/communitymeeting01.cfm are relevant.

SPLICE a real-time data distribution service
Dealing with real-time in Openwings

In addition to these draft specifications an alpha evaluation kit consisting of a small command & control system based on a real-time data distribution service is being contributed. Furthermore, there are several publications on SPLICE available on the internet that explain the features and benefits of distributed systems composed of autonomous applications relying on a real-time information distribution service.

3.2 Explanation of how these items might be used as a starting point for the work.

These items describe the purpose, the architecture and the solution-direction of the intended service.

Section 4: Additional Information (Optional)

4.1 This section contains any additional information that the submitting Member wishes to include in the OSR.

None.