tailieunhanh - Towards an Internet-Scale XML Dissemination Service

Publish/subscribe systems have demonstrated the ability to scale to large numbers of users and high data rates when providing content-based data dissemination services on the Internet. However, their services are limited by the data semantics and query expressiveness that they support. On the other hand, the recent work on selective dissemination of XML data has made significant progress in moving from XML filtering to the richer functionality of transformation for result customization, but in general has ignored the challenges of deploying such XML-based services on an Internet-scale. In this paper, we address these challenges in the context of incorporating the rich functionality of XML data dissemination in a highly scalable system. We present. | Towards an Internet-Scale XML Dissemination Service Yanlei Diao Shariq Rizvi Michael J. Franklin University of California Berkeley diaoyl rizvi franklin @ Abstract Publish subscribe systems have demonstrated the ability to scale to large numbers of users and high data rates when providing content-based data dissemination services on the Internet. However their services are limited by the data semantics and query expressiveness that they support. On the other hand the recent work on selective dissemination of XML data has made significant progress in moving from XML filtering to the richer functionality of transformation for result customization but in general has ignored the challenges of deploying such XML-based services on an Internet-scale. In this paper we address these challenges in the context of incorporating the rich functionality of XML data dissemination in a highly scalable system. We present the architectural design of ONYX a system based on an overlay network. We identify the salient technical challenges in supporting XML filtering and transformation in this environment and propose techniques for solving them. 1 Introduction A large number of emerging applications such as mobile services stock tickers sports tickers personalized newspaper generation network monitoring traffic monitoring and electronic auctions has fuelled an increasing interest in ContentBased Data Dissemination CBDD . CBDD is a service that delivers information to users equivalently applications or organizations based on the correspondence between the content of the information and the user data interests. Figure 1 shows the context in which a data dissemination system providing this service operates. Users subscribe to the service by providing profiles expressing their data interests. Data sources publish their data by pushing messages to the system. The system delivers to each user the messages that match her This work was funded in part by the NSF under ITR grants .

• Quản trị mạng
• ecall or difficulties
• Medicines adherence
• encouraging patients
• Salt Tolerance
• Harvested Fruits
• Fruits and Vegetables
• sometimes conflicting
• generate strong
• public and private meanings
• clearly understood