How do I tell what is causing my Data Aggregator to go into a Degraded state?

Release : 3.7

Component : IM Polling

Create an on-demand report for the Data Aggregator component for the following 2 variables. We want to show the metrics by component so set the view type to be "Chart per Item with Multiple Metrics" then set the "Metric Calculate Level" to By component. 

Data Aggregator Event Calculation Times : Percent Of Poll Cycle To Complete - Maximum
Data Aggregator Event Calculation Times : Number Of Processed Timestamps - Average

Run the report for around the time frame that the the threshold sate was degraded

The report will show you which metric family is causing the event processing to take a long time. You can then adjust the amount of event thresholding you are doing on that metric family to reduce the load.