avro 模式中的时间戳在 Kafka Connect 中产生不兼容的值验证 JDBC

Question

JDBC 接收器连接器产生的错误：

org.apache.kafka.connect.errors.DataException: Invalid Java object for schema type INT64: class java.util.Date for field: "some_timestamp_field"
at org.apache.kafka.connect.data.ConnectSchema.validateValue(ConnectSchema.java:242)
at org.apache.kafka.connect.data.Struct.put(Struct.java:216)
at org.apache.kafka.connect.transforms.Cast.applyWithSchema(Cast.java:151)
at org.apache.kafka.connect.transforms.Cast.apply(Cast.java:107)
at org.apache.kafka.connect.runtime.TransformationChain.apply(TransformationChain.java:38)
at org.apache.kafka.connect.runtime.WorkerSinkTask.convertMessages(WorkerSinkTask.java:480)
at org.apache.kafka.connect.runtime.WorkerSinkTask.poll(WorkerSinkTask.java:301)
at org.apache.kafka.connect.runtime.WorkerSinkTask.iteration(WorkerSinkTask.java:205)
at org.apache.kafka.connect.runtime.WorkerSinkTask.execute(WorkerSinkTask.java:173)
at org.apache.kafka.connect.runtime.WorkerTask.doRun(WorkerTask.java:170)
at org.apache.kafka.connect.runtime.WorkerTask.run(WorkerTask.java:214)
at java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:511)
at java.util.concurrent.FutureTask.run(FutureTask.java:266)
at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1149)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:624)
at java.lang.Thread.run(Thread.java:748)

源 JDBC 连接器 (MySQL) 注册的 avro 模式:

{  
   "type":"record",
   "name":"ConnectDefault",
   "namespace":"io.confluent.connect.avro",
   "fields":[  
      ...
      {  
         "name":"some_timestamp_field",
         "type":{  
            "type":"long",
            "connect.version":1,
            "connect.name":"org.apache.kafka.connect.data.Timestamp",
            "logicalType":"timestamp-millis"
         }
      },
      ...
   ]
}

看起来异常是由于此代码块引起的：https://github.com/apache/kafka/blob/f0282498e7a312a977acb127557520def338d45c/connect/api/src/main/java/org/apache/kafka/connect/data/ConnectSchema.java#L239

因此，在 avro 架构中，时间戳字段注册为具有正确（时间戳）逻辑类型的 INT64。但是 connect 将模式类型读取为 INT64 并将其与值类型 java.util.Date.

进行比较

这是一个错误，还是有解决办法？可能是我遗漏了一些东西，因为这看起来像一个标准的连接模型。

提前致谢。

更新

接收器连接器配置：

{
    "name": "sink",
    "config": {
        "connector.class": "io.confluent.connect.jdbc.JdbcSinkConnector",
        "tasks.max": "1",
        "topics": "topic",
        "connection.url": "jdbc:postgresql://host:port/db",
        "connection.user": "user",
        "connection.password": "password",

        "key.converter": "io.confluent.connect.avro.AvroConverter",
        "key.converter.schema.registry.url": "http://host:port",
        "value.converter": "io.confluent.connect.avro.AvroConverter",
        "value.converter.schema.registry.url": "http://host:port",

        "auto.create": "true",
        "insert.mode": "upsert",
        "pk.mode": "record_value",
        "pk.fields": "id"
    }
}

Kafka 中的反序列化数据：

{
   "id":678148,
   "some_timestamp_field":1543806057000,
   ...
}

Answer 1

我们已经解决了这个问题work around。我们的目标是将 id 从 BIGINT 转换为 STRING(TEXT/VARCHAR) 并将记录保存在下游数据库中。

但是由于一个问题（可能是 https://issues.apache.org/jira/browse/KAFKA-5891），强制转换 id 字段无效。 Kafka 也试图验证转换链中的时间戳字段，但读取模式 type/name 错误并导致类型不匹配（请参阅上面的记录正文和错误日志）。

所以我们做了如下解决：

extract only the id field as key -> execute cast transform on the key -> it works as key does not contain timestamp field.

这里是变通的配置：

{
    "name": "sink",
    "config": {
        "connector.class": "io.confluent.connect.jdbc.JdbcSinkConnector",
        "tasks.max": "1",
        "topics": "topic",
        "connection.url": "jdbc:postgresql://host:port/db",
        "connection.user": "user",
        "connection.password": "password",

        "key.converter": "io.confluent.connect.avro.AvroConverter",
        "key.converter.schema.registry.url": "http://host:port",
        "value.converter": "io.confluent.connect.avro.AvroConverter",
        "value.converter.schema.registry.url": "http://host:port",

        "transforms": "createKey,castKeyToString",
        "transforms.createKey.type": "org.apache.kafka.connect.transforms.ValueToKey",
        "transforms.createKey.fields": "id",

        "transforms.castKeyToString.type": "org.apache.kafka.connect.transforms.Cast$Key",
        "transforms.castKeyToString.spec": "id:string",

        "auto.create": "true",
        "insert.mode": "upsert",
        "pk.mode": "record_key",
        "pk.fields": "id"
    }
}

免责声明：这不是一个合适的解决方案，只是一种解决方法。铸造变换中的错误应该被修复。在我看来，转换转换应该只关注指定用于转换的字段，而不是消息中的其他字段。

祝你有美好的一天。

avro 模式中的时间戳在 Kafka Connect 中产生不兼容的值验证 JDBC

Timestamp in avro schema produces incompatible value validation in Kafka Connect JDBC

jdbc

apache-kafka

apache-kafka-connect

confluent-platform