Changes to operators and PEs in a running job

The streamtool updateoperators command works on a subgraph, which is defined by a parallel region.

The operators in the parallel region are the target operators. Target operators also include any new operators that are created when the parallel region width is increased. When you change the width of a parallel region in a running job, they are fused into new PEs and restarted.  

Collateral operators are operators that have a relationship with the target operators:

• Fused in the same PE as a target operator
• Fused into the same PE as other collateral operators
• Connect with the parallel region with a splitter or a merger

When you change the width of a parallel region in a running job, the configurations of the collateral operators are not changed, but they are also fused into new PEs and restarted.