@Kiran Hebbar Hello, Your question is not very clear as to what you are looking for. I am going to assume you are asking how to view the metadata currently associated with a FlowFile passing through your NiFi dataflow(s). There are several ways to view this metadata: Right click on a connection that has queued data and select "List queue" from the context menu. Form the new UI that opens you will se a list of FlowFiles. Click on the icon to the left of any one of the FlowFiles to "view details" of that FlowFile. There you will find a "attributes" tab that list all the key/value pairs associated to this FlowFile. Use data provenance to perform a search on FlowFile events. "Data Provenance" can be found under the upper right corner hamburger menu in the NiFi UI. Click the search icon to open a "Search Events" UI where you can add criteria to limit the results (Provenance returns 1000 of the most recent events). From the final list use the same "view details" icon to the left of an event to open a new UI that will show the Attributes of your selected FlowFile. Use the LogAttribute processor. Add this processor anywhere in your dataflow. As FlowFile pass through this processor their FlowFile Attributes as they exist at the time of passing through this processor will be logged to the nifi-app.log. Keep in mind that this processor can greatly increase the size of your logs and require more space to store your logs. If you found this answer addressed your question, please mark it as accepted. Thanks, Matt ... View more

@Alvaro Dominguez The primary node could change at anytime. You could use postHTTP and listenHTTP processor to route FlowFiles from multiple nodes to a single node. My concern would be heap usage to merge (zip) 160K FlowFiles on a single NiFi node. The FlowFile metadata for all those FlowFiles being zipped would be help in heap memory until the zip is complete. Any objection to having a zip of zips? In other words you could still create 4 unique zip files (1 per node each with unique filename), then send these zipped files to one node to be zipped once more in to a new zip with the single name you want written into HDFS. Thanks, Matt ... View more

@Alvaro Dominguez The only way to create one single zip file is to have one node perform the zipping of all the files. This sounds less then ideal. How large are each of these individual zip files and how many FlowFiles on average go in to each zip file? ... View more

@Alvaro Dominguez Multiple nodes can write to the same path in HDFS, but not the same file at the same time. The lease error you saw above is moist likely the result of one node completing writing .example_1202.zip and then renaming it example_1202.zip. In between that time, a different node saw and then tried to start appending to .example_1202.zip, but it was moved/renamed before that could happen. It essentiall becomes a race condition since nodes do not communicate thsi kind of information with one another. You could write 4 zip files to HDFS every minute. You could just name each filename uniquely based on NiFi hostname writing file. Thanks, Matt ... View more

@Alvaro Dominguez Every node in a NiFi cluster runs its own copy of the cluster flow, has its own repositories, and works on its own set of FlowFiles. Nodes in a NiFi cluster are unaware of any FlowFiles being processed by other nodes in the cluster. What you are seeing is normal expected behavior of your dataflow. Thanks, Matt ... View more

@Oleksandr Solomko Any other ERROR or WARN log messages? --- Is this a standalone NiFi installation or a multi-node NiFi cluster? - If cluster, are all these FlowFiles queued on just one node? --- Is this Nifi secured (HTTPS or HTTP)? I can't reproduce locally. Thanks, Matt ... View more