Each Processor, Process Group, and Remote Process Group on the canvas provides several statistics about how much data has been processed by the component. These statistics provide information about how much data has been processed in the past five minutes. This is a rolling window and allows us to see things like the number of FlowFiles that have been consumed by a Processor, as well as the number of FlowFiles that have been emitted by the Processor.

The connections between Processors also expose the number of items that are currently queued.

It may also be valuable to see historical values for these metrics and, if clustered, how the different nodes compare to one another. In order to see this information, we can right-click on a component and choose the Stats menu item. This will show us a graph that spans the time since NiFi was started, or up to 24 hours, whichever is less. The amount of time that is shown here can be extended or reduced by changing the configuration in the properties file.

In the top-right corner of this dialog is a drop-down that allows the user to select which metric they are viewing. The graph on the bottom allows the user to select a smaller portion of the graph to zoom in.