Running the Java code on the conductor node (DataStage)

The Java™ Integration stage supports the execution of Java code on the conductor node during initialization and termination of stages.

To execute the Java code on the conductor, your Java code calls the setIsRunOnConductor method of the Capabilities class. During the initialization of the stage, the Processor class calls the following methods:
  1. getCapabilities()
  2. validateConfiguration()
  3. initialize()
During initialization, some of the additional methods of the Processor class are called in the following scenarios:
  • If the validateConfiguration method returns false, the getConfigurationErrors method is called.
  • If runtime column propagation is enabled on one output link and the getBeanForOutput method is implemented to return the JavaBean object, then the following methods of the Processor class are called during initialization:
    1. getCapabilities()
    2. validateConfiguration()
    3. getBeanForOutput()
    4. getAdditionalOutputColumns()
  • If the capability that runs of your Java code on the conductor node and runtime column propagation are both enabled on at least one output link associated with the JavaBean object, then the following methods of the Processor class are called in the specified order during initialization. The validateConfiguration method is called twice on the conductor node.
    1. getCapabilities()
    2. validateConfiguration()
    3. getBeanForOutput()
    4. getAdditionalOutputColumns()
    5. validateConfiguration()
    6. initialize()

During the termination of a stage, the terminate() method of the Processor class is called.

The following example Java code is used to set the capability to run the methods of the Processor class on the conductor node for initialization and termination of stage. 

public Capabilities getCapabilities()
{
   Capabilities capabilities = new Capabilities();
   capabilities.setIsRunOnConductor(true); 
   return capabilities;
}

The Java code checks the return value of the getNodeNumber method of the Configuration class to identify whether the method is called on the conductor node or player nodes. If the return value is -1 the method runs on the conductor node. If the return value is any other number, for example 0 or 1, the method is invoked on player nodes.

In the following example, the Processor class completes initialization and termination processes on the conductor node and player nodes.

private int m_nodeID = -1;   
public boolean validateConfiguration(Configuration configuration, boolean isRuntime) throws Exception 
{    
...    
m_nodeID = configuration.getNodeNumber();    
...    
return true; 
}  

public void initialize() throws Exception 
{    
if (m_nodeID == -1) // On Conductor    
   {       
     // Perform any initialization process on the conductor node     
   }    
   else    
   {       
     // Perform any initialization process on each player node    
   } 
}  

public void terminate(boolean isAborted) throws Exception 
{    
   if (m_nodeID == -1)  // On Conductor    
   {       
    // Perform any termination process on the connector node    
   }    
   else    
   {       
   // Perform any termination process on each player node    
   } 
}