How to get Validation error message into a Attribute from ValidateResult Processor of Nifi

Question

I am trying to validate a json using ValidateRecord Processor via Avroschemaregistry. I need to store validation error message into a sql table, so i tried to capture the error message in attribute but i am unable to capture the error message in attribute, any idea how to do it

Answer 1

After your ValidateRecord Processor, you can choose to route flow files which are 'invalid' to a separte log and route them to your sql table, you can do the same if they 'fail'. I am assuming from the 'error message' you mean the 'bullentin' which would occur when the Processor can neither validate or invalidate the flow file based on your schema.

A potential solution to this is to use the SiteToSiteBulletinReportingTask

Screenshot of SiteToSiteBulletinReportingTask

You can build a dataflow to receive these bulletin events, manipulate them as you want and store them in a location of your choice for your auditing needs.

From the sounds of it, the SiteToSiteBulletinReportingTask should be able to achieve what you want. To implement this, add a iteToSiteBulletinReportingTask to the 'Reporting Tasks' in the NiFi Settings: Reporting Tasks in NiFi Settings

You can name your input port and have it flow towards your SQL store and you should have what you're after.

You need to allow NiFi nodes to receive data via site-to-site on the input port and you also need to grant the correct permissions on the root process group so the nodes are able to see the component, view and modify the data.

Side note: I would usually log everything, and have all failures and invalid route to log files, which I put to store, e.g. HBase/SQL. One suggestion I've seen is configure the logging subsystem to additionally send specific error categories to your destination of choice (e.g. active notification vs passive parsing of logs). NiFi is leveraging a very flexible logback system (an evolution of log4j). The best part - changes to the $NIFI_HOME/conf/logback.xml configuration file do not require an instance restart, will be picked up within 30 seconds or less.