I set up a process group to pull ~10^8 S3 files, consolidate them and save to HDFS. My FetchS3Object processor fails after 2-17 hours with the following error. When this happens, a ConsumeKafka_2_6 processor in a separate group fails with the same error message. Other processors have this message flicker in and out, but can typically self-resolve.     16:29:54 UTC ERROR FetchS3Object[id=50cb6c89-c4a3-3df6-807b-7f92555fd572] FetchS3Object[id=50cb6c89-c4a3-3df6-807b-7f92555fd572] failed to process session due to Failed to import data from com.amazonaws.services.s3.model.S3ObjectInputStream@1a9a94ff for StandardFlowFileRecord[uuid=bd5ccda4-d432-4086-8f4f-bb763afd108b,claim=,offset=0,name=Apr-2020/20200420-17H53M38S.json,size=0] due to org.apache.nifi.processor.exception.FlowFileAccessException: Unable to create ContentClaim due to java.io.FileNotFoundException: /opt/nifi/content_repository/993/1627576194712-2847713 (No such file or directory); Processor Administratively Yielded for 1 sec: org.apache.nifi.processor.exception.FlowFileAccessException: Failed to import data from com.amazonaws.services.s3.model.S3ObjectInputStream@1a9a94ff for StandardFlowFileRecord[uuid=bd5ccda4-d432-4086-8f4f-bb763afd108b,claim=,offset=0,name=Apr-2020/20200420-17H53M38S.json,size=0] due to org.apache.nifi.processor.exception.FlowFileAccessException: Unable to create ContentClaim due to java.io.FileNotFoundException: /opt/nifi/content_repository/993/1627576194712-2847713 (No such file or directory)     The only way I've found to fix it is to reboot the NiFi node mentioned in the error message. Sometimes that resolves it immediately; other times the error message shifts to a different node and I have to play whack-a-mole before it resolves. When I connect to a problem node, its file system works fine (plenty of space, can read, write, etc), but that directory (/opt/nifi/content_repository) is empty. On healthy nodes, that directory is full of subdirectories.    On a problem node, log files showed the same error message as above (no extra details). When I lower the FetchS3Object ConcurrentTask count (Ex 100 to 5), it can run longer before an error, but it hits the same error eventually.    Any help would be much appreciated. The closest error message I found in existing posts pointed to too many open files, but that wasn't part of the error messages I've been getting.  ... View more