Confluent InfluxDB 接收器连接器

Question

我正在尝试使用 Confluent InfluxDB sink connector 将主题中的数据获取到我的 InfluxDB 中。配置如下：

connector.class=io.confluent.influxdb.InfluxDBSinkConnector
influxdb.url=https://mydb
topics=mytopic
tasks.max=1

当我通过 Kafka Connect UI 创建新连接器时，我得到的只是以下异常：

org.apache.kafka.connect.errors.ConnectException: Exiting WorkerSinkTask due to unrecoverable exception.
    at org.apache.kafka.connect.runtime.WorkerSinkTask.deliverMessages(WorkerSinkTask.java:587)
    at org.apache.kafka.connect.runtime.WorkerSinkTask.poll(WorkerSinkTask.java:323)
    at org.apache.kafka.connect.runtime.WorkerSinkTask.iteration(WorkerSinkTask.java:226)
    at org.apache.kafka.connect.runtime.WorkerSinkTask.execute(WorkerSinkTask.java:194)
    at org.apache.kafka.connect.runtime.WorkerTask.doRun(WorkerTask.java:175)
    at org.apache.kafka.connect.runtime.WorkerTask.run(WorkerTask.java:219)
    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)
Caused by: java.lang.ClassCastException: java.lang.String cannot be cast to org.apache.kafka.connect.data.Struct
    at io.confluent.influxdb.InfluxDBSinkTask.put(InfluxDBSinkTask.java:109)
    at org.apache.kafka.connect.runtime.WorkerSinkTask.deliverMessages(WorkerSinkTask.java:565)
    ... 10 more

主题中的值是这样的 json 字符串：{"pid":1,"filename":"test1.csv"}。这里有什么我遗漏的配置吗？

更新：这是我的工作人员配置：

config.storage.topic=kafka-connect-my-config
rest.port=28082
group.id=kafka-connect-mygroup
plugin.path=/usr/share/java,/connect-plugins
key.converter=org.apache.kafka.connect.storage.StringConverter
offset.storage.topic=kafka-connect-my-offsets
bootstrap.servers={my broker urls}
value.converter=org.apache.kafka.connect.storage.StringConverter
status.storage.topic=kafka-connect-my-status
internal.key.converter.schemas.enable=false
internal.value.converter.schemas.enable=false
rest.advertised.host.name=kafka-development-kafka-connect-1
internal.value.converter=org.apache.kafka.connect.json.JsonConverter
internal.key.converter=org.apache.kafka.connect.json.JsonConverter

Answer 1

InfluxDB 连接器要求数据中存在模式，因此如果您有 JSON 数据，则需要设置

value.converter=org.apache.kafka.connect.json.JsonConverter
value.converter.schemas.enable=true

但是您的 JSON 需要包含架构，所以不是

{"pid":1,"filename":"test1.csv"}

你需要类似的东西

{
    "schema": {
        "type": "struct", "optional": false, "version": 1, "fields": [
            { "field": "pid", "type": "string", "optional": true },
            { "field": "filename", "type": "string", "optional": true }
        ]
    },
    "payload": {
        "pid": 1,
        "filename": "test1.csv"
    }
}

参考：https://rmoff.net/2020/01/23/notes-on-getting-data-into-influxdb-from-kafka-with-kafka-connect/

有关如何将架构应用于数据的更多详细信息，请参阅this blog

有关一般转换器的更多详细信息，请参阅this article。