You can use ExecuteScript with Groovy and the following script (assuming your input is newline-delimited): def flowFile = session.get() if(!flowFile) return def header = '' session.read(flowFile, { inStream -> header = new BufferedReader(new InputStreamReader(inStream)).readLine() } as InputStreamCallback) flowFile = session.putAttribute(flowFile, 'header', header) session.transfer(flowFile, REL_SUCCESS) This puts the first line in an attribute called 'header', which you can use with RouteOnAttribute to decide where to send the flow. Note that this script doesn't do error handling, but you could put a try/catch around the session.read to session.transfer, the catch could route the flow file to REL_FAILURE. ... View more

Avro doesn't like the dots in the attribute names (which become field names), perhaps you could rename them (with UpdateAttribute or at the source processor(s)) using underscores (or other valid characters like alphanumeric characters, see the link for the rules). ... View more

I don't believe it is currently possible to convert/use the decimal type in the Avro processors, I have written up NIFI-3000 to cover this improvement. If you are comfortable with a scripting language like Javascript or Groovy, you could use the ExecuteScript processor, point the Module Directory property at JAR(s) for Avro 1.8.0, and code the conversion yourself. However beware that you don't do additional Avro processing downstream, as that will likely break (because of the bug in NIFI-3000). ... View more

Does the term "avro-schema" (from your error message) appear in the schema? If so, then the error is because it doesn't like the dash, you can only use upper- and lower-case letters and underscores for the first character, then that set plus digits for all remaining characters (see Naming section of Avro doc). Try replacing the dash with an underscore and it should work. ... View more

The code for ScanContent looks like it watches the specified file for changes; otherwise it shouldn't refresh the dictionary file (unless something weird happens with the internal search mechanism). Alternatively, I answered a Stack Overflow question with a similar use case, using ExecuteScript to check the JSON (and in their case, replace the value from an external file). That example also reads the file every time, but you could use a similar approach with InvokeScriptedProcessor to read the file in the initialize() method, then it will not be re-read during onTrigger (which is called when the processor is scheduled). ... View more