Version 59 (modified by bartek, 12 years ago) (diff)

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QCG-Notification

QCG-Notification is an open source implementation of the family of WS-Notification standards (Base Notification, Brokered Notification and Topics). It supports the topic-based publish/subscribe pattern for the asynchronous message exchange among Web Services and other involved entities. The main architecture of our system is based on a highly efficient, extended version of the Notification Broker, managing all items participating in notification events. Today, QCG-Notification offers sophisticated notification capabilities, e.g. notification message filtering, push and pull messages delivery, and it was successfully integrated with different communication protocols as well as various Web Services' security mechanisms. The modular architecture of QCG-Notification also provides a great opportunity for developers to build new extensions and plugins to meet other specific requirements.

Features

From the architecture perspective, QCG-Notification exposes a well-defined Web Service interface corresponding to the role of Notification Broker as well as it offers other standard interfaces for managing Subscriptions and Pull Points. It supports advanced two-layer notification filtering based on hierarchical topic namespaces and XPath queries on the content of messages.

All funtions offered by QCG-Notification can be invoked using different transport protocols. Currently, our system on a server side supports the SOAP communication over HTTP, HTTPS, and XMPP. In turn, the client side (Publisher side) of the system is based on dynamically loaded plugins. Currently QCG-Notification offers here SOAP over HTTP, HTTPS and XMPP as well as SMTP (e-mail) protocol. Thanks to the XMPP based communication, all notification parties, namely Subscribers, Publishers, Notification Consumers and QCG-Notification itself, can be located behind firewalls with only well defined outgoing TCP/IP port open for the XMPP transport communication.

Performance

The low-level architecture of QCG-Notification is based on highly efficient mechanisms and data structures. We compared the three notification systems that confirmed the good performance of our sollution. See Benchmarks for details.

Installation

Depending on the requirements, installation instructions are availble at the following links:

If you want to update an existing QCG-Notification installation use the link presented below:

see also

Related software

  •  QCG-Core - generic library, must be installed in the system prior to the installation of QCG-Notification.
  • QCG-XMPP - plugins for Pidgin may be utilized for enabling WS-Notifications in the popular XMPP communicator.

Applications

  • QosCosGrid - In this projectd QCG-Notification together with other Web Services using the QosCosGrid framework, in particular QCG-Computing, was used to build highly efficient grid middleware for cross-cluster parallel application execution and monitoring.
  • BREIN - QCG-Notification was demonstrated in asynchronous and dynamic message exchange in a distributed IT system controlling some events generated by an example airport management system, such as flight delays, SLA violations, etc.
  • PL-Grid - QCG-Notification is going to be productively used under the national grid infrastructure initiative in Poland.
  • Mapper - In the Mapper project, QosCosGrid stack is exploited to perform multiscale computations on EGI and PRACE resources.

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