question Re: NiFi - Split a record using a non-root JSON attribute in Support Questions

NiFi - Split a record using a non-root JSON attribute

brotmanz — Wed, 07 Aug 2019 02:52:34 GMT

I have JSON input of the following format:

{
  "Id": 1000000,
  "ReportName": TestReport,
  "Results": [{
    "Id": 1,
    "ResultId": "1000000-0",
    "Query": {
      "Id": 001,
      "Name": "TestQuery0",
    }
  }, {
    "Id": 2,
    "ResultId": "1000000-1",
    "Query": {
      "Id": 002,
      "Name": "TestQuery1",
    }
  }]
}

These file can become quite large depending on the number of Results in the Report and I was hoping to convert the single Flowfile to multiple records for processing. However, due to the format of the JSON a SplitRecord will result in one record per split. There is one report per FlowFile and therefore only 1 root level element.
I am looking for a method or strategy to split the Flowfile into smaller Records while still maintaining the cohesiveness of the report in the end when it put in HDFS.

Current Strategy:

Use JoltTransformJSON to inject report information into each result
Use SplitRecord to split the Flowfile on each result
Process Records
Use MergeRecord to get the modified Flowfile in Step1
Convert to original Flowfile (Not sure of the best method here)
Use MergeContent and push to HDFS

Any advice would be appreciated! Thank you

Re: NiFi - Split a record using a non-root JSON attribute

mburgess — Sat, 10 Aug 2019 00:46:30 GMT

If I am reading your use case correctly, I think you're looking for what the ForkRecord processor does; it allows you to fork a (usually single) record into multiple records based on a Record Path (similar to JSONPath but different syntax and expressiveness), possibly keeping the "root" elements common to each outgoing record.

Re: NiFi - Split a record using a non-root JSON attribute

brotmanz — Tue, 08 Oct 2019 20:36:38 GMT

Thank you for the response. This was the correct answer, but I was unable to verify until recently.