Introduction

This article describes how the substitution of parameter values works in JobScheduler. It also describes how to use parameters in shell script, API Jobs and pre- and postprocessing scripts.

Substitution of parameter values by the JobScheduler

The JobScheduler can substitute the values of environment variables in task parameters using ${<env_var>}.

The JobScheduler will substitute ${<env_var>} with an empty value if the environment variable is unknown.


To prevent substitution the environment variable can be quoted with a backslash - i.e. \${<env_var>}

Example

<job  name="job_environment">
    <params >
        <param  name="param_from_environment" value="the value of scheduler_home is ${SCHEDULER_HOME} ${test}"/>
    </params>

    <script  language="shell">
        <![CDATA[
echo %SCHEDULER_PARAM_PARAM_FROM_ENVIRONMENT%
        ]]>
    </script>

    <monitor  name="process0" ordering="0">
        <script  language="java:javascript">
            <![CDATA[
function spooler_process_before(){
    spooler_log.info("param_from_environment=" + spooler_task.params.var("param_from_environment"));
    return true;
}
            ]]>
        </script>
    </monitor>

    <run_time />
</job>

This job will produce the following output:

2015-12-07 10:39:32.458+0100 [info]   SCHEDULER-918  state=starting (at=2015-12-07 10:39:32.403+0100)
2015-12-07 10:39:33.984+0100 [info]   param_from_environment=the value of scheduler_home is C:/Program Files/sos-berlin.com/jobscheduler/scheduler_current 
2015-12-07 10:39:33.987+0100 [info]   SCHEDULER-987  Starting process: "C:\WINDOWS\TEMP\\sos-A4CFC1B980.cmd"
2015-12-07 10:39:34.019+0100 [info]   [stdout]  
2015-12-07 10:39:34.019+0100 [info]   [stdout] C:\Users\ur\Documents\sos-berlin.com\jobscheduler\scheduler_current>echo the value of scheduler_home is C:/Program Files/sos-berlin.com/jobscheduler/scheduler_current   
2015-12-07 10:39:34.019+0100 [info]   [stdout] the value of scheduler_home is C:/Program Files/sos-berlin.com/jobscheduler/scheduler_current 

Please note:

• ${test} has been substituted to an empty value
• To access the value of the parameter in a shell script, the name has to be prefixed. The default value of the prefix is:
  • SCHEDULER_PARAM_
  • This prefix can be set by the scheduler.variable_name_prefix parameter which is defined in the $scheduler_data/config/scheduler.xml file.
    
    • JobScheduler has to be restarted after the value of the prefix has been changed.

<?xml version="1.0" encoding="ISO-8859-1" standalone="no"?>
<?xml-stylesheet type="text/xsl" href="scheduler_documentation.xsl" ?>
<spooler>
 
        <config mail_xslt_stylesheet="config/scheduler_mail.xsl" port="4102">
        
                <params>
                        <param name="scheduler.variable_name_prefix" value="SCHEDULER_PARAM_"/>
                        <param name="scheduler.order.keep_order_content_on_reschedule" value="false"/>
                </params>

Note: JobScheduler does NOT substitute environment variables in order parameters.

Substitution of parameter values by sos.scheduler.managed.configuration.ConfigurationOrderMonitor

An additional substitution mechanism for jobs running in a job chain is provided by the  sos.scheduler.managed.configuration.ConfigurationOrderMonitor preprocessing Java class:

This Java class implements:

• Before processing:
  • it copies the node parameters that are configured in jobchain.config.xml to the order parameters
  • if an order parameter exists with the same name then it will be overwritten
  • substitutes all ${<param>} variables with:
    • JobScheduler parameters that are configured in the $scheduler_data/config/scheduler.xml file,
    • task parameters that are configured in the currently running job,
    • order parameters that are configured with the order,
    • node parameters that have been copied to the order parameters.
• After processing:
  • deletes all node parameters from the order.

Please note:

• If a task parameter value is to be substituted by the Configuration Monitor then the value has to be quoted with a backslash to prevent its substitution by the JobScheduler
  • Example: a value \${param}
• With the parameter setting scheduler.order.keep_order_content_on_reschedule=true the values will be substituted only in the first run.
• When using node parameters then the Configuration Monitor has to be assigned to the job
  • JOE will assign the Configuration Monitor automatically when configuring a node parameter in a job chain
  • Should no substitution be performed then please check if the Configuration Monitor is assigned to the job. Otherwise assign parameters individually by using JOE.

Substitution of parameter values by JITL Jobs that extend the JobSchedulerJobAdapter base class

Some JITL Jobs extend the JobSchedulerJobAdapter base class and some older jobs extend JobSchedulerJob. For a detailed list see here: JITL Jobs - Status

This article describes the substitution mechanisms for JITL Jobs that extend the JobSchedulerJobAdapter base class.

Substitution is carried out for:

• task parameters and
• order parameters

The following patterns are recognized as parameters to be substituted:

• %param%
• ${param}
  
  

Where param can be:

• a task parameter
• an order parameter
• a node parameter
• a scheduler parameter
• some special parameters (see the list below)

List of special parameters:

• Parameters named param  and scheduler_param_param will be treated as being identical.
• Parameters named param_plus_any_understrikes  and  paramplusanyunderstrikes will be treated as being identical.

Note: Substitution applies exclusively to the current job run. This means that the values of the parameters will be unchanged after the execution of the job. If you have an order parameter param_x whose value is value is ${param_y} and there are two steps in the job chain, the value of param_x after the execution of the first node will still be value is ${param_y}