Demonstrations of Collaborative Web Services and Peer-to-Peer Grids

Article excerpt

Abstract: Peer-to-Peer Grids is a new trend in scientific computing and collaboration. It is based on the Peer-to-Peer and Grids technologies and leverages the advantages of both. We develop our collaborative PowerPoint and IE (Internet Explorer) applications with a common Peer-to-Peer Grid architecture. We make NaradaBrokering as our dynamic messaging environment and systematic use of Web Services as one type of our building blocks. Making PowerPoint and Internet Explorer applications collaborative using their Event Metadata and Instant Messaging as Web Services is useful in situations such as long distance education [2, 4] and web conferencing [6]. This is also a good process of demonstrations of harnessing and leveraging of the power and richness of Web Services and Peer-to-Peer Grids computing.

Key Words: Collaborative PowerPoint and IE, Web Service, Peer-to-Peer Grids

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1. The Big Picture

We have developed collaborative PowerPoint applications, one of which is a master client that lectures and broadcasts its event messages to all participating clients. The participating clients of the collaborative PowerPoint receive and deal with the event messages, and render the process of the presentation individually. The applications including Microsoft PowerPoint and the resources of PowerPoint presentation files are deployed beforehand to each and every client so that control and communication of the whole process are message based. By using string-based event messages we improve the speed and efficiency of the collaboration performances because it lowers the Internet traffic greatly as compared to Shared Display, which is based on transferring image data like bitmaps.

Another type of participating clients is of IE (Internet Explorer) style, in which the IE is automated and the slides of the presentation are loaded and rendered inside the IE browser. This is suitable in situations where IE browser is preferable.

We use NaradaBrokering messaging service [14, 15] as the message environment to communicate event messages during the process. Together with the Network infrastructure, it correlates the elements of the Peer-to-Peer Grids, and therefore makes the collaboration possible.

Grids computing offers robust, structured, security services that scale well in pre-existing hierarchically arranged enterprises or organizations; it is largely asynchronous and allows seamless access to supercomputers and their datasets.

Peer-to-Peer is more convenient and efficient for the low-end clients to advertise and access the files on the communal computers; it is more intuitive, unstructured, and largely synchronous.

We have also developed and deployed Instant-Messaging Web Services to further improve the message communication and make it more portable and extensible in the Internet collaboration era.

We make the collaborative PowerPoint applications use the Instant Message as a Web Service by using XML (eXtensible Markup Language) and SOAP (Simple Object Access Protocol) protocol. We get and save the event message Metadata of the PowerPoint presentations, and make them as Web Services, so that the presentations can be rendered asynchronously as well as synchronously.

2. A Collaborative Web Service Model

We use a Shared Input Port Model [1, 3] for our collaborative PowerPoint and IE applications and web services, as in Figure 1.

In this model, the resource-facing input/output ports supply the information which is to define the state of the Web Service; the user-facing input, output ports pass control information by the user, and supply information for constructing the user interfaces. The messages on these ports define the state and results of each Web Service.

We have defined a protocol XGSP (XML General Session Protocol), which is an XML-based protocol to describe registration, session parameters, session membership, negotiation, etc. …