Data creation Error creating a kafka message to producer - Expected start-union. Got VALUE_STRING [duplicate] - avro

Question

Unable to Error creating a kafka message to producer - Expected start-union. Got VALUE_STRING
{
"namespace": "de.morris.audit",
"type": "record",
"name": "AuditDataChangemorris",
"fields": [
{"name": "employeeID", "type": "string"},
{"name": "employeeNumber", "type": ["null", "string"], "default": null},
{"name": "serialNumbers", "type": [ "null", {"type": "array", "items": "string"}]},
{"name": "correlationId", "type": "string"},
{"name": "timestamp", "type": "long", "logicalType": "timestamp-millis"},
{"name": "employmentscreening","type":{"type": "enum", "name": "employmentscreening", "symbols": ["NO","YES"]}},
{"name": "vouchercodes","type": ["null",
{
"type": "array",
"items": {
"name": "Vouchercodes",
"type": "record",
"fields": [
{"name": "voucherName","type": ["null","string"], "default": null},
{"name": "authocode","type": ["null","string"], "default": null}
]
}
}], "default": null}
]
}
when i was trying to create a sample data in json format based on the above avsc for kafka consumer i am getting the below error upon testing
{
"employeeID": "qtete46524",
"employeeNumber": {
"string": "custnumber9813"
},
"serialNumbers": {
"type": "array",
"items": ["363536623","5846373733"]
},
"correlationId": "corr-656532443",
"timestamp": 1476538955719,
"employmentscreening": "NO",
"vouchercodes": [
{
"voucherName": "skygo",
"authocode": "A238472ASD"
}
]
}
getting the below error when i got when i ran the dataflow job in gcp
Error message from worker: java.lang.RuntimeException: java.io.IOException: Insert failed: [{"errors":[{"debugInfo":"","location":"serialnumbers","message":"Array specified for non-repeated field: serialnumbers.","reason":"invalid"}],"index":0}]**
how to create correct sample data based on the above schema ?

Answer 1

Read the spec
The value of a union is encoded in JSON as follows:
if its type is null, then it is encoded as a JSON null;
otherwise it is encoded as a JSON object with one name/value pair whose name is the type’s name and whose value is the recursively encoded value
So, here's the data it expects.
{
"employeeID": "qtete46524",
"employeeNumber": {
"string": "custnumber9813"
},
"serialNumbers": {"array": [
"serialNumbers3521"
]},
"correlationId": "corr-656532443",
"timestamp": 1476538955719,
"employmentscreening": "NO",
"vouchercodes": {"array": [
{
"voucherName": {"string": "skygo"},
"authocode": {"string": "A238472ASD"}
}
]}
}
With this schema
{
"namespace": "de.morris.audit",
"type": "record",
"name": "AuditDataChangemorris",
"fields": [
{
"name": "employeeID",
"type": "string"
},
{
"name": "employeeNumber",
"type": [
"null",
"string"
],
"default": null
},
{
"name": "serialNumbers",
"type": [
"null",
{
"type": "array",
"items": "string"
}
]
},
{
"name": "correlationId",
"type": "string"
},
{
"name": "timestamp",
"type": {
"type": "long",
"logicalType": "timestamp-millis"
}
},
{
"name": "employmentscreening",
"type": {
"type": "enum",
"name": "employmentscreening",
"symbols": [
"NO",
"YES"
]
}
},
{
"name": "vouchercodes",
"type": [
"null",
{
"type": "array",
"items": {
"name": "Vouchercodes",
"type": "record",
"fields": [
{
"name": "voucherName",
"type": [
"null",
"string"
],
"default": null
},
{
"name": "authocode",
"type": [
"null",
"string"
],
"default": null
}
]
}
}
],
"default": null
}
]
}
Here's an example of producing and consuming to Kafka
$ jq -rc < /tmp/data.json | kafka-avro-console-producer --topic foobar --property value.schema="$(jq -rc < /tmp/data.avsc)" --bootstrap-server localhost:9092 --sync
$ kafka-avro-console-consumer --topic foobar --from-beginning --bootstrap-server localhost:9092 | jq
{
"employeeID": "qtete46524",
"employeeNumber": {
"string": "custnumber9813"
},
"serialNumbers": {
"array": [
"serialNumbers3521"
]
},
"correlationId": "corr-656532443",
"timestamp": 1476538955719,
"employmentscreening": "NO",
"vouchercodes": {
"array": [
{
"voucherName": {
"string": "skygo"
},
"authocode": {
"string": "A238472ASD"
}
}
]
}
}
^CProcessed a total of 1 messages