Overriding operator properties

When you submit a job, you can optionally override the properties of the operators in your application bundle file. For example, if you plan to fuse a set operators into the same processing element, you might need to change the partitionIsolation setting to false for all operators that you plan to fuse into the processing element.

Before you begin

To use a submission-time parameter that affects how operators are fused, you must specify a fusion scheme other than legacy. This means that you must recompile your applications with IBM® Streams Version 4.2 or later.

About this task

You can specify the operator properties from the IBM Streams Console or the streamtool submitjob command. However, if you use the streamtool submitjob command, you must use a job configuration overlay file to specify these settings. A job configuration overlay file is optional if you use IBM Streams Console.

To override the properties of an operator, you must specify the following information:
nameSpec
You can specify the name of a single operator or you can specify a group of operators:
  • To override the properties of a single operator, specify the name of an existing operator instance in the application after UDP transformations.
  • To override the properties of a group of operators, use an asterisk (*) as a wildcard character. You can specify 0 or more wildcard characters. For example:
    • Enter myParallelRegion.myOperator[*] to specify all of the channels of the parallel region
    • Enter MyComposite.firstComposite.* to specify all of the operators in the composite operator
    Tip: Wildcard characters can be especially helpful when operators with related concerns are named following a particular pattern. For example, if the application has several FileSink operators that are all used for debugging, including "Debug" in their name allows you to easy control all of their behavior at the same time.
partitionIsolation
Specify true if the operator requires an isolated processing element, which means that the operator is the only operator in the processing element. No other operators are in the processing element.
hostIsolation
Specify true if the operator requires an isolated resource, which means that only the processing element that contains the specified operator is located on the resource. No other processing elements are deployed on the resource.