@HiSunny
The configured "run schedule" on a NiFi processor controls how often the processor is scheduled to execute. The "concurrent tasks" controls the parallel execution of a processor. When a processor is scheduled to execute it will request a thread from the NiFi Max Timer Driven thread pool that will be used to execute the processor code. If that thread is still active upon next scheduled Execution and not all concurrent tasks are in use yet, the processor can request another thread to execute in parallel.
When it comes to variables, If the processor property support NiFi Expression Language (NEL) with an evaluation using FlowFile attributes, then each FlowFile via FlowFile attributes can provide unique input to the execution.
You can see if a property supports Expression language by floating your cursor of the "?" icon next to each property name. You'll want to make sure the scope of NEL support supports FlowFile attributes.
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Thank you,
Matt
