合流kafka-avro生产者模式错误

Question

我使用https://github . com/confluent Inc/confluent-Kafka-python/blob/master/examples/avro _ producer . py中的示例代码将数据加载到主题中。我只做了一个更改，那就是我添加了“default”:为了模式兼容性，每个字段都为null。它加载得很好，因为我可以在http://localhost:9021/中看到消息和模式。如果我通过cli运行kafka-avro-console-consumer命令，我还可以看到进入主题的数据。但是尝试用https://docs . confluent . io/current/connect/Kafka-connect-AWS-redshift/index . html中提供的配置使用红移sink，得到如下所示的错误。然而，如果我没有在字段中添加“default”:null，那么它会一直运行到最后。任何指导将不胜感激。

org.apache.kafka.connect.errors.SchemaBuilderException: Invalid default value
    at org.apache.kafka.connect.data.SchemaBuilder.defaultValue(SchemaBuilder.java:131)
    at io.confluent.connect.avro.AvroData.toConnectSchema(AvroData.java:1812)
    at io.confluent.connect.avro.AvroData.toConnectSchema(AvroData.java:1567)
    at io.confluent.connect.avro.AvroData.toConnectSchema(AvroData.java:1687)
    at io.confluent.connect.avro.AvroData.toConnectSchema(AvroData.java:1543)
    at io.confluent.connect.avro.AvroData.toConnectData(AvroData.java:1226)
    at io.confluent.connect.avro.AvroConverter.toConnectData(AvroConverter.java:108)
    at org.apache.kafka.connect.storage.Converter.toConnectData(Converter.java:87)
    at org.apache.kafka.connect.runtime.WorkerSinkTask.lambda$convertAndTransformRecord$1(WorkerSinkTask.java:491)
    at org.apache.kafka.connect.runtime.errors.RetryWithToleranceOperator.execAndRetry(RetryWithToleranceOperator.java:128)
    at org.apache.kafka.connect.runtime.errors.RetryWithToleranceOperator.execAndHandleError(RetryWithToleranceOperator.java:162)
    at org.apache.kafka.connect.runtime.errors.RetryWithToleranceOperator.execute(RetryWithToleranceOperator.java:104)
    at org.apache.kafka.connect.runtime.WorkerSinkTask.convertAndTransformRecord(WorkerSinkTask.java:491)
    at org.apache.kafka.connect.runtime.WorkerSinkTask.convertMessages(WorkerSinkTask.java:468)
    at org.apache.kafka.connect.runtime.WorkerSinkTask.poll(WorkerSinkTask.java:324)
    at org.apache.kafka.connect.runtime.WorkerSinkTask.iteration(WorkerSinkTask.java:228)
    at org.apache.kafka.connect.runtime.WorkerSinkTask.execute(WorkerSinkTask.java:200)
    at org.apache.kafka.connect.runtime.WorkerTask.doRun(WorkerTask.java:184)
    at org.apache.kafka.connect.runtime.WorkerTask.run(WorkerTask.java:234)
    at java.base/java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:515)
    at java.base/java.util.concurrent.FutureTask.run(FutureTask.java:264)
    at java.base/java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1128)
    at java.base/java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:628)
    at java.base/java.lang.Thread.run(Thread.java:834)
Caused by: org.apache.kafka.connect.errors.DataException: Invalid value: null used for required field: "null", schema type: INT32
    at org.apache.kafka.connect.data.ConnectSchema.validateValue(ConnectSchema.java:220)
    at org.apache.kafka.connect.data.ConnectSchema.validateValue(ConnectSchema.java:213)
    at org.apache.kafka.connect.data.SchemaBuilder.defaultValue(SchemaBuilder.java:129)

Answer 1

添加“default： null”是不够的，您需要将类型修改为如下内容：

type: ["null", "string"], default: null

注意在第一个位置的类型中添加“null”，即。没有

type: ["string", "null"], default: null

见讨论：http://apache-avro.679487.n3.nabble.com/How-to-declare-an-optional-field-tp4025089p4025094.html