@Nera Majer I tried on my local instance and everything works as expected. - If you have .gz file in local FS then try to fetch the file ListFile+FetchFile from your local FS(instead of HDFS) and check are you able to fetch the whole file without any issues?. - Move Local file to HDFS using the below command. hadoop fs -put <local_File_path> <hdfs_path> then check are u able to get the file size as 371kb in hdfs? - If yes then try to run ListHDFS+FetchHDFS processors to fetch the newly moved file into HDFS directory. - Some threads related to similar issue. https://community.hortonworks.com/questions/106925/error-when-sending-data-to-api-from-nifi.html https://issues.apache.org/jira/browse/NIFI-5879 ... View more