Clear the cache of FetchDistributedMapCache processor

Question

How to clear the cache of FetchDistributedMapCache processor in Apache NiFi? I tried deleting the persisted directory and also tried giving a new directory all together but it still fetches old data. Thanks for your help.

Answer 1

You should be able to stop the DistributedMapCacheClient and DistributedMapCacheServer, then delete the existing DistributedMapCacheServer and create a new one with same port as the previous one, then start them back up.

Answer 2

Inside NiFi, you could create a new DistributedMapCacheServer and point your processor at that instead. Outside of NiFi, I've written a Groovy script where you can interact with the DistributedMapCacheServer from the command line. The API only allows you to remove entries you know about; in the upcoming NiFi 1.2.0 release, you will be able to remove entries using a regular expression for the keys (implemented in NIFI-3627). At that point I will update the Groovy script to enable that feature.