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An implementation note: parameterized nodes are only expanded when they are ready to run. Thus if a graph contained an execute node (e0) followed by a parameterized node (p0), and the latter also had a graph containing an execute node (e1) followed by another parameterized node (p1), (p0) would only get expanded after (e0) ran, and for each member j produced by (p0), each (p1j) would get expanded only after its corresponding (e1j) had run.
Failure
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Constraint Type
The contents of this element, if expressed, is a comma-delimited list of dependencies which must successully complete for this node to run. The default behavior is that all of its dependencies must be satisfied.
An alternative to expressing these constraints is to set the "tolerance" attribute; this indicates the percentage of dependencies which must successfully complete for this node to run. Default = 1.0. The latter is useful for programming a node which acts as a barrier on a large group of parameterized nodes, all results of which may not be necessary for the node to execute or for valid results to be obtained from the workflow. When expressed on a workflow, these constraints are applied to its leaf (that is, final, or childless) nodes.
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