@Tarek Elgamal Assuming you are referring to settings for "Max Timer Driven Thread count"? That setting controls the max number of threads that can execute at one time. Does not guarantee any order to the execution of threads. NiFi's controller in the back ground does not operate under this thread pool. Both processors will be scheduled to run based on their configured run schedule. Those concurrent tasks then get stacked in a request queue waiting on one of the threads from that pool to service them. This way, every processor is eventually going to get a chance to run thier code. Also keep in mind that some processors work on batches of FlowFiles while others process one FlowFile per task. Also hard to say that each processed FlowFile will take same amount of time to complete an operation. Really depends on processor and what it is designed to do. Thanks, Matt ... View more