Versions Compared

Key

  • This line was added.
  • This line was removed.
  • Formatting was changed.

...

  • The solution implements a job named sorter that can be added at the start of any job chain.
    • This job implements a spooler_process() function that suspends all incoming orders.
    • This job is configured for a single task and with an idle timeout attribute. This means that it will execute incoming orders sequentially.
    • Having received the last available order this job will wait for the duration specified with the idle_timeout attribute for new orders. 
      • The idle timeout is configured using, for example <job idle_timeout="10"> with the sorter job definition.
      • Once the idle timeout has expired this job will execute its spooler_exit() function and then sort and move all orders that have previously been suspended.
        • Sorting is done in alphabetical order.
        • The orders are moved to the next job chain node that follows the sorter job in the job chain.
  • The download example uses a job chain named job_chain1 that includes the job nodes for the sorter job and a hello job. This job chain accepts ad hoc orders that are added by JOC and it can easily be modified to watch for incoming files and to create an order for each file.
  • Hint: to re-use the sorter job you can:
    • store the job in a central folder and reference the job in individual job chains.
    • move the job's JavaScript code to a central location and use an appropriate <include> element for individual job scripts.

Job: request_resource_lock

  • This job can be used by resource lock consumers as the first job node in a job chain.
  • The job has no special job script implementation.

    Image Added

  • The job makes use of the Monitor request_resource_lock.

    Image Added

Monitor: request_resource_lock

This Monitor implements a pre-processing script for jobs that request resource locks. 

Code Block
languagejs
titleMonitor request_resource_lock
collapsetrue
function spooler_process_before() {
    var	resourceJobChainParamDefault = "/resource_lock_provider/resource_lock_provider";
    var resourceLockJobChainParam = "resource_job_chain";
    var resourceLockNameParam = "resource_lock";
    var resourceLockWakeUpParam = "resource_lock_wake_up";

	var order = spooler_task.order;
    var params = spooler.create_variable_set();
  		params.merge( spooler_task.params );
  		params.merge( order.params );

    // name of the requested resource: explicitely set by parameter or assuming the current job chain path
    var resourceLock = params.value( resourceLockNameParam );
    if ( !resourceLock ) {
		resourceLock = order.job_chain.path;
	}

    // name of the job chain that handles resource locks
    var resourceJobChainName = params.value( resourceLockJobChainParam );
    if ( !resourceJobChainName ) {
    	resourceJobChainName = resourceJobChainParamDefault;
    }

	// order wake up parameter indicates that order has acquired resource lock
    if ( params.value( resourceLockWakeUpParam ) == "yes" ) {
		spooler_log.info( ".. order acquired resource lock: " + resourceLock );
		return true;
    } else if ( params.value( resourceLockWakeUpParam ) == "no" ) {
		spooler_log.info( ".. order suspended and waiting for resource lock: " + resourceLock );
    	order.state = order.job_chain_node.state;
		order.suspended = true;
		return false;
	}

    var resourceJobChain = spooler.job_chain( resourceJobChainName );
    var resourceOrder = spooler.create_order();

    var resourceParams = spooler.create_variable_set();
    resourceParams.set_var( "requestor_job_chain", order.job_chain.path );
    resourceParams.set_var( "requestor_order", order.id );
    resourceOrder.params = resourceParams;

	resourceOrder.title = resourceLock;
	resourceOrder.at = "now+3";

    if ( (order.job_chain.path + "/" + order.id).length <= 100 ) {
		resourceOrder.id = order.job_chain.path + "/" + order.id;
    } 

    resourceJobChain.add_order( resourceOrder );
    spooler_log.info( ".. order requested resource lock: " + resourceLock );

	params.set_var( resourceLockWakeUpParam, "no" );
    order.state = order.job_chain_node.state;

    // always suspend current order, it will be waked up by the requested resource lock
    order.suspended = true;

	return false;
}

Usage

  • Add two orders to the job_chain1 job chain. 
    • Use an order ID in descending alphabetical order, e.g. "cba" for the order ID of the first order and "abc" for the order ID of the second.
  • Both orders will be suspended at the first node of the job chain.
  • After an idle timeout of 10s both orders will be moved to the next job node in the job chain. 
    • This time the orders will be processed in ascending alphabetical order.

...