Marfill, If backpressure is applied when the total number of flowfiles in a given queue has reached (#nodes * the limit per node) for example if you have a cluster of 3 nodes and the threshold is set to 10,000 then the backpressure will be applied when total # of flow files = 30,000 and so on. Regarding the Control Rate I believe its done per node statistics, for example if you have a control rate that allows 1 flow file per hour and the control rate processor is set part of load balancing on 3 nodes cluster, let say you receive total of 3 files for the first time  one on each node then the 3 will be get processed immediately. ... View more