Managing Service Groups

A Service Group is a convenient way of deploying multiple services in one service archive file. There is a logical relationship between the services at runtime. The only difference in the services.xml for a service group and a single service is its root element. For a service group, the root element is <serviceGroup>, and we have multiple <service> elements inside the <serviceGroup> element.

For example,

<serviceGroup>
<service name=Test1>
...
<service>
<service name=Test2>
...
</service>
</serviceGroup>

The following sections describe how to manage service groups:

Accessing Service Groups

Follow the instructions below to manage the parameters of a service group.

1. Click the Main tab on Management Console and then go to Manage -> Services and click List. The Deployed Services screen appears.
    
2. Click the deployed service group(s) link to access the deployed service groups.
   
3. In the Deployed Service Groups screen that appears, click the required service group to see the relevant Service Group Dashboard screen.
   

Managing Parameters of the Service Group

Parameters can be defined inside services.XML as an immediate child element of the service element. These parameters can be accessed using the message context at runtime or via AxisService or AxisOperation. A parameter has two attributes:

• name - The mandatory attribute which specifies the name of a parameter.
• locked - The optional attribute. The idea of a "locked" attribute is to express whether we allow the parameter value to be overridden by a child node in the hierarchy.

For example, if a parameter was added in the axis2.xml file with the locked attribute set to True, then if a service tries to add another parameter with the same name, it will give an exception. You can add easily add service group parameters via the Management Console.

To add a new service group parameter

1. On the Actions panel in the Service Group Dashboard screen, click Parameters.
    
2. Click Add New to create a new service parameter.
   
3. On the window that appears, enter the service group parameter name and click OK to add the parameter to the list.
    
4. Enter the value of the parameter.
   
5. Click Update to save the new parameter in the service group.
   
   
   

To delete a service group parameter

1. On the Actions panel in the Service Group Dashboard screen, click Parameters.
2. Click Delete based on the parameter you want to delete.
   
3. Confirm that you are sure you want to delete the parameter by clicking Yes on the window that appears.

Managing Module Engagements

There are instances when it is impossible to run the service without engaging the WS-Security module into the service. Engaging a module is just a matter of adding a module tag in the services.XML file. If the module is available, it can engage. Else it becomes a faulty service.

To engage a module into your service group

1. On the Actions panel in the Service Group Dashboard screen, click Modules.
   
2. Select the required a module from the drop down list. WSO2 ESB provides the following modules that you can engage into your service group:
   
   • rampart-1.61-wso2v14 - Provides the WS-Security and WS-SecureConversation functionalities for Axis2, based on Apache WSS4J, Apache XML-Security and Apache Rahas implementations.
   • relay-4.4.1.20 - Unwraps the binary messages coming from the message relay for admin services.
   • rahas-1.61-wso2v14 - Is used to STS enable a service where it adds the RequestSecurityToken operation to a service that the module is engaged to.
3. Click Engage.

For more information on modules, see Working with Modules.

Creating the Archive File

• On the Actions panel in the Service Group Dashboard screen, click Create Service Archive. This creates the service archive file and downloads it to the Downloads directory on your computer.