All, I wanted to describe an issue on a nifi instance we've been using 0.4.1 on, and why diagnosing it and reproducing it may be difficult. This is on a linux server, where we have a reasonably high load, and the error happens infrequently, but when it does, it really gums up operations.
At some point we get an IOException for too many open files. (with an awfully high limit of open files in ulimit, so not sure why that is happening). Some time later, when trying to read a flowfile in a processor, we get a ContentNotFoundException because presumably a flowfile is pointing to content that was never written. When this happens, we basically have to remove the flowfile manually (and if no one is watching at the moment or the processor that reads isn't configured to handle this, or if you're not using 0.5.x where you can selectively remove flowfiles from a queue this can cause operational challenges). Because this happens so infrequently, I'm not sure if others have seen this. I'm not sure if something in the framework may need to adjustment if a content claim goes wrong, but I really didn't expect that a flowfile with no actual content should be able to be created, which seems to be what happened (rather than the content being deleted or corrupted). Anyone else experience this, or know maybe if something in 0.5.X may have addressed this (looking through the release notes, nothing jumped out). Tony
