Streams Studio provides a very useful feature where the instance graph can be color coded according to the value a of metric, using color schemes. By having your operators define custom metrics with values that reflect your application’s state, you can then create a Streams Studio color scheme that maps those values to colors.
Here with a custom gauge metric where 1 represents the operator is the leader and 0 it is a follower, a color scheme represents the leader as red, and the follower as yellow. Note color schemes allow colors to be mapped to ranges of values as well as specific values.
As the metric value changes, the instance graph will update the operator colors, for example, changing an operator to yellow to red when it becomes the leader. This coloring is also reflected in the processing element (PE) view when the PE contains an operator with that metric.
Thus this allows an easy approach to visual your application graph while it is running, based upon application specific details, such as coloring by percentage of dropped calls in a mobile phone call analysis application.