When using the DistributeMapCache, how do I know how it behaves? Do I have control over time-to-live, eviction strategy etc? Can I see what it contains, or only do single specific key lookups? ... View more

Thanks a lot, Matt. Good solution and example. I'm currently restricted to an old NiFi (version 1.1), and wasn't aware of the notify/wait pattern available in newer versions. From which version is that available, and where in general can I lookup from which version a particular feature/processor is available? Will soon be working on a newer HDF 3.1, so hopefully that will unlock new needed features. - I still didn't quite get whether FetchSFTP (used with ListSFTP) will reuse connection across multiple file fetches, or it open/closes for every flowfile processed. Regards and thanks Henrik ... View more

In general, I have some trouble seeing how to best match up file pairs like <datafile> and <datafile>.sha256, as they come in separate flowfiles through NiFi, with no relation at all. I've tried to use the distributed mapcache (storing checksums given in .sha256 files), but not sure it's the best way, and I don't see how to control time-to-live, size etc for it. Some wishes. Track which file exist without checksum and vice versa (for notification of possible errors). Allow some time for file pairs (datafile + checksum) to complete (might be a race condition between upload them to SFTP from external source and my ListSFTP). Ideas on this pattern with accompanying checksum files? ... View more