Installation

This document describes the standard installation using Tomcat as a web container. However, the CEC is written as a standards compliant J2EE application, so should be capable of being installed in any J2EE container. Please see the reference guide for possible variations. Below is listed the dependent components that are used in writing and testing of the CEC - we recommend that this

  • Use SUN Microsystem's implementation of Java 5. You only need the Java Runtime Environment package; you don't need the full Java Development Kit.
  • Use Apache-Tomcat 5.5 as the web-container.

Tomcat users and roles

In Tomcat's tomcat-users.xml file, make sure that you have at least one user with the manager role.

Naming the web-application context

You must choose a name for the "context" in which the web-application runs. This name will become part of the URLs for your CEC web-service and the web pages of your CEC web-application. E.g., if you name the web-application context "CEC-1", the URLs will be of the form http://your.server.address:8080/CEC-1/
http://your.server.address:8080/CEC-1/services/CommonExecutionConnectorService
respectively.

This context identifier is also used when saving the initial configuration file as described in the configuration section

Security

The CEC is fully compliant with current IVOA security standards. This means, amongst other things, that the CEC supplies a delgation service which allows the CEC to act on behalf of the caller to access other secure services - e.g. VOSpace. To configure the necessary security settings within Tomcat please see the security configuration instructions.

If you do not set up this CEC to have this level of security then it will still be able to communicate with VOSpace servers that allow unauthenticated access.

VOSpace

This version of the CEC web-application can use IVOA-standard VOSpace to obtain parameter values and store results. This should not require any furhter configuration beyond setting a registry location as detailed below.

In Addition, this CEC works with AstroGrid's FileManager component to read and write files in AstroGrid MySpace. The details of which stores to use are set by the clients of the web-application in requests to the CEC web-service. You do not need to supply your own FileManager to operate the CEC web-application.

Registry

Your web application uses an IVOA resource-registry to publicize its capabilities (as well as discovering other services such as VOSpace). You must have access to a registry in which you can publish your resources and a registry from which your CEC can search for resources at run-time.

The publishing registry and the searchable registry may be the same service. In this case, you will typically use an external registry. As an alternative, you may choose to run a local publishing registry. This makes it easier to publish and maintain groups of services on your site and also helps you establish a "brand" for your services by associating them with your own publishing authority. If you want to run a publishing registry, then you should install and set up the AstroGrid registry component before setting up your CEC.

Installation procedure

  1. Obtain a copy of the WAR file for the CEC from the AstroGrid software site. See the guide to downloading for details.
  2. Rename the WAR file to match the chosen name of the web-application context; e.g. CEC-1.war if the context is CEC-1 as in the example above.
  3. Copy your renamed WAR file into the webapps sub-directory of your Tomcat installation. Wait a few seconds. Tomcat notices the WAR file, unpacks the web-application into a sub-directory tree in the webapps directory and starts the web-application.
  4. Check that the web-application has started correctly by going, with a web-browser, to the root of the web application (http://your.server.address:8080/CEC-1/ in the example above). If no web-page is returned, then there is a problem with the installation of the WAR, and you should consult the tomcat log files to try to discover the reason.
  5. Now set up your web-application by following the instructions in the configuration guide.