Messaging

From Ogce

Contents

Introduction

OGCE WS-Messenger is a “publish-subscribe” based message broker implemented on top of Apache Axis2 web services stack. It implements latest WS-Eventing and WS-Notifications specifications.

WS-Messenger supports topic based subscriptions as well as XPath based subscriptions. Additionally broker is capable of converting message formats between two specifications, hence offering more flexibility to users. Moreover, users may deploy WS-Messenger either as a standalone distribution or embedded in a web container such as Tomcat. Please refer the user guide for more details.

Features

  • Topic based and Xpath based subscriptions
The current version supports only “simple topic expressions” specified in WS-Topic specification. However, the broker supports XPath-based filtering with the use of Yfilter library. Thus, user have the option to filter massages sent by all publishers or messages sent for a particular topic.
  • Switch between message formats
Message publishers and consumers are allowed to use either ws eventing protocol or ws-notifications protocol interchangeably . In other words, a message published using ws-eventing protocol can be received using ws-notificaions protocol by a consumer, vise versa.
  • Java NIO support
Binary distribution of OGCE WS-Messenger is configured with axis2 nio transport. This boosts the performance of broker specially in situations where number of subscriptions becomes larger.
  • Multiple deployment modes
In order provide greater flexibility OGCE WS Messenger provides number of deployment options. For example user has the option to run broker as a standalone service or deploy it on servlet container. Additionally message delivery component can be decoupled from broker and deployed on a separate servlet container; which is particularly useful in order to distribute load. Please refer to user guide for more information.
  • Message box service
Message box allows clients that do not have endpoints such as clients sitting behind firewall or running as applets inside a browser to use message box address as their address. Messages received by this service will be stored in a database, so clients may retrieve them later.
  • Workflow tracking API
Provides a flexible API to track scientific work flows which is based on functionality provided by broker.

Pre-requisites

  • Mandatory
    • Java (v 1.5 or higher)
    • Maven2 (v 2.2.0 or higher)
    • Axis2 (v 1.5 or higher)
    • Mysql Server (v 5.4.1 or higher)
  • Optional - These are optional requirements depending on configurations. please refer to user guide for more information:
    • Apache Tomcat (version 6.x.xx)
    • Axis2 WAR (Web Archive) Distribution (version 1.5 or higher)
    • Ant (version 1.7.1 or higher)

Download

Releases

Version SVN Resources
1.1.1 https://ogce.svn.sourceforge.net/svnroot/ogce/incubator/OGCE-WS-Messenger/tags/1.1 binary, docs, src-dist
1.1 https://ogce.svn.sourceforge.net/svnroot/ogce/incubator/OGCE-WS-Messenger/tags/1.1 binary, docs, src-dist
1.0 https://ogce.svn.sourceforge.net/svnroot/ogce/incubator/OGCE-WS-Messenger/tags/1.0 binary, docs, src-dist

Please refer to documentation build and deploy OGCE WS-Messenger from source and for available configuration options.

Latest Code

Latest source code and relevant libraries can be checked out using a SVN client

svn co https://ogce.svn.sourceforge.net/svnroot/ogce/incubator/OGCE-WS-Messenger/trunk

Using Client API

OGCE WS messenger is built on top of Apache Axis2 web services stack. Therefore, In order to use client API, users are required to add Axis2 libraries to java class path during the run time. Please refer to user guide and samples provided in binary distribution for more details.


GUI Tools & Samples

WS-Eventing Listener GUI is useful for monitoring the event traffic and debugging in the distributed systems. This GUI can listen to the events sent by the broker. Please refer to user guide for more details.

Samples included in binary distribution provide comprehensive guide on how to use the client API provided by OGCE messenger. Alternatively latest samples are located here.

Messaging User Guide

Messaging User Guide explains how to build messenger from source and different deployment modes. Additionally user guide explains all the configurations possible for broker and message box as well.

Web site tools