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4.0 Task Graph Metadata

A Task Graph within the context of Triana refers to an XML document which represents a group unit or the entire Triana Network. Potential use cases for task graph metadata:

  1. A task graph will be used by OCL to execute the entire network as set out;
  2. A task graph representing a group unit will be used to provide details on tools available;
  3. A task graph can be used as a record of the experiment and this record can be used to reconstruct the experiment and also pass it around to other scientists for replication.
  4. A task graph can be used as a check-pointing mechanism to migrate if necessary.

For example, this interface could be as simple as:

String saveState();
// which returns a string of the checkpointed Triana i.e. to serialize
Triana’s state

Void restoreState(String state);
// to restore the state within Triana i.e. to deserialize

Requirements include:

  1. Name and id of task graph
  2. Description
  3. Tasks comprising the task graph
  4. Connections between the tasks
  5. Layout metadata
  6. Metadata on host machine

A simple task graph example is included below:

<?xmlversion="1.0" encoding="UTF-8"?>
  <taskgraph>
  <name> </name>
  <description> </description>
  <parameters>
    <param name="" value= ""/>
  </parameters>
  <!-- List of tools participating in this task graph -->
  <tasks>
    <task toolname="" taskname="" taskid="">
    <description> </description>
    <data>
        <inportnum> </inportnum>
        <outportnum> </outportnum>
        <input>
           <type> </type>
        </input>
        <output>
           <type> </type>
        </output>
        </data>
        <parameters>
           <inportnum> </inportnum>
           <outportnum> </outportnum>
            <input>
               <param name="" value=""/>
            </input>
            <output>
               <param name="" value=""/>
            </output>
               <param name="" value=""/>
        </parameters>
    </task>
  </tasks>
  <!-- List of connections between nodes on tools in this task graph-->
  <connections>
    <connection>
        <source taskid="" node=""/>
        <target taskid="" node=""/>
    </connection>
  </connections>
  <!-- information about how tools within this task graph are visually
     grouped and displayed -->
  <layout>
    <task taskid=""/>
    <group>
        < task taskid=""/>
        < task taskid=""/>
    </group>
    <group>
        <group>
           <task taskid=""/>
           <task taskid=""/>
        </group>
        <task taskid=" "/>
    </group>
  </layout>
</taskgraph>


GridLab: Grid Application Toolkit and Testbed is co-funded by the European Commission under the Fifth Framework Programme (IST-2001-32133).
Web admin: Petr Holub, web design: Radoslaw Strugalski
Last update on Tuesday, 27-Aug-2002 15:10:10 CEST.