Session Configuration Document

Each data service resource that is deployed will have its own session configuration document. This file is used to configure the session manager component of the data service resource. The session manager is used to create, access and terminate the sessions that perform document requests are joined to. An introduction to sessions was provided by the Sessions Page of the Background Reading section.

The session configuration document allows the service deployer to specify the session manager factory implementation class. This is a class that defines a factory method for creating the session manager instance. That instance will then be used by the data service resource during its lifetime. OGSA-DAI includes the uk.org.ogsadai.sessions.impl.TransientSessionManagerFactory which is a factory that creates instances of a transient session manager. This transient session manager stores the sessions that it creates in memory without persisting them to database or file. It is the default implementation used for all new data service resources that are deployed.

The session configuration document also allows the specification of the default and maximum timeout values for new sessions that are created by the session manager. Finally, the document may contain a collection of static session attributes. Recall that these are special session attributes that will occur in every new session created by the session manager.

Examples

The first example shows a default session configuration document specifying the standard session manager factory, a default timeout of 600000 milliseconds and a maximum timeout of 120000 milliseconds.

<?xml version="1.0" encoding="UTF-8"?>
<sessionConfiguration
  xmlns="https://ogsadai.org.uk/namespaces/2005/10/config"
  xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
  xsi:schemaLocation="https://ogsadai.org.uk/namespaces/2005/10/config
  path/to/schema/ogsadai/xsd/sessions_config.xsd">
  <sessionManagerFactory
    impl="uk.org.ogsadai.sessions.impl.TransientSessionManagerFactory">
    <timeout default="600000" max="1200000"/>
  </sessionManagerFactory>
</sessionConfiguration>

The second example expands on the first by introducing two statis session attributes. Objects of the specified implemetation classes will be created and added to every new session. They will be retrievable using the specified names.

<?xml version="1.0" encoding="UTF-8"?>
<sessionConfiguration
  xmlns="https://ogsadai.org.uk/namespaces/2005/10/config"
  xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
  xsi:schemaLocation="https://ogsadai.org.uk/namespaces/2005/10/config
  path/to/schema/ogsadai/xsd/sessions_config.xsd">
  <sessionManagerFactory
    impl="uk.org.ogsadai.sessions.impl.TransientSessionManagerFactory">
    <timeout default="600000" max="1200000"/>
    <sessionAttribute
      name="MySessionAttribute1"
      impl="package.name.MyAttributeValueClass">
      <anyXML/>
    </sessionAttribute>
    <sessionAttribute
      name="MySessionAttribute2"
      impl="package.name.MyOtherAttributeValueClass">
      <anyXML/>
    </sessionAttribute>
  </sessionManagerFactory>
</sessionConfiguration>

Notice that the sessionAttribute elements allow any XML child elements. These may optionally be used by the attribute value implementation class for configuration purposes.

Specification

The document root element must be a sessionConfiguration element containing:

• One sessionManagerFactory element with an impl attribute specifying a class name that implements the uk.org.ogsadai.sessions.SessionManagerFactory interface. In most cases the value of this attribute will be uk.org.ogsadai.sessions.impl.TransientSessionManagerFactory.
  • One timeout element containing default and max attributes for specifying the default and maximum timeouts in milliseconds for new sessions that are created by the session manager.
  • Zero or more sessionAttribute elements each containing a name and an impl attribute and optionally containing any child XML element.
    • The name attribute specifies the name that can be used for retrieving the static session attribute from the session.
    • The impl attribute specifies a class name that implements the uk.org.ogsadai.sessions.SessionAttributeValue interface
    • Any child XML element will be passed to the initialise method of the object of the class specified by the impl attribute.
  • Zero or one configuration element containing any XML child element. This element is passed to the createSessionManager factory method of the session manager factory. It is not used by the default session manager factory provided with OGSA-DAI.

XML Schema

OGSA-DAI/schema/ogsadai/xsd/sessions_config.xsd