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Posted to users@nifi.apache.org by "Kuhfahl, Bob" <rk...@mitre.org> on 2018/08/13 15:02:15 UTC

Need a sample JSON input file for InferAvroSchema

Trying to develop a sample input file of json data to feed into InferAvroSchema so I can feed that into PutDatabaseRecord.
Need a hello world example ☺

But, to get started, I’d be happy to get InferAvroSchema working.  I’m “trial and error”-ing the input file hoping to get lucky, but..

No log messages, flow of json data is going to failure,  I’m reading the code for InferAvroSchema()
But it just calls  JsonUtil.inferSchema(), so I’ll keep digging down the path but… if someone has a sample input that demonstrates how it’s supposed to work, I’d be grateful!

Re: Need a sample JSON input file for InferAvroSchema

Posted by Matt Burgess <ma...@apache.org>.

Bob,

InferAvroSchema can infer types like boolean, integer, long, float, double,
and I believe for JSON can correctly descend into arrays and nested
maps/structs/objects. Here is an example record from NiFi provenance data
that has most of those covered (except bool and float/double, but you can
add those):

{
  "eventId" : "7422645d-056e-423b-b280-6305f9daccaa",
  "eventOrdinal" : 0,
  "eventType" : "CREATE",
  "timestampMillis" : 1496934288944,
  "timestamp" : "2017-06-08T15:04:48.944Z",
  "durationMillis" : -1,
  "lineageStart" : 1496934288930,
  "componentId" : "8821e5d8-015c-1000-30b0-f7211bbf43e5",
  "componentType" : "GenerateFlowFile",
  "componentName" : "_GenerateFlowFile",
  "entityId" : "b99a56c6-e032-4396-915e-24186974b84a",
  "entityType" : "org.apache.nifi.flowfile.FlowFile",
  "entitySize" : 52,
  "updatedAttributes" : {
    "path" : "./",
    "uuid" : "b99a56c6-e032-4396-915e-24186974b84a",
    "filename" : "924304881186293"
  },
  "previousAttributes" : { },
  "actorHostname" : "localhost",
  "contentURI" : "
http://localhost:8989/nifi-api/provenance-events/0/content/output",
  "previousContentURI" : "
http://localhost:8989/nifi-api/provenance-events/0/content/input",
  "parentIds" : [ ],
  "childIds" : [ ],
  "platform" : "nifi",
  "application" : "NiFi Flow"
}

 Note that the timestamps are longs as InferAvroSchema does not support
Avro logical types (such as timestamp, date, decimal). I'd like to see an
InferRecordSchema that is record-aware, supports time/date types, etc. I
wrote up a Jira a while back to cover it [1] but haven't gotten around to
implementing it yet.

Regards,
Matt

[1] https://issues.apache.org/jira/browse/NIFI-4109


On Mon, Aug 13, 2018 at 11:02 AM Kuhfahl, Bob <rk...@mitre.org> wrote:

> Trying to develop a sample input file of json data to feed into
> InferAvroSchema so I can feed that into PutDatabaseRecord.
>
> Need a hello world example ☺
>
>
>
> But, to get started, I’d be happy to get InferAvroSchema working.  I’m
> “trial and error”-ing the input file hoping to get lucky, but..
>
>
>
> No log messages, flow of json data is going to failure,  I’m reading the
> code for InferAvroSchema()
>
> But it just calls  JsonUtil.inferSchema(), so I’ll keep digging down the
> path but… if someone has a sample input that demonstrates how it’s supposed
> to work, I’d be grateful!
>
>
>
>
>
>
>
>
>
>
>