@yong lau - If you don't want to use a dataflow to redistribute your to be merged to a single node, the only other option you have is to control the delivery of the source data that is going to be merged to a single node. - You'll need to ask yourself: How are these files which you want to merge getting to your NiFi? Can that be controlled so this particular flow of data goes to one node in your cluster only? - Thanks, Matt ... View more