无法读取Kafka-Avro架构消息

Question

有没有解决这个问题的方法？？？我无法读取KAFKA-AVRO架构消息。我正在尝试将消息从logstash发送到KAFKA到hdfs。

以下是技术堆栈：

1. LogStash 2.3-当前生产版本
2. 汇流3.0。
3. 插件：A。Logstash-kafka-Output插件B。logstash-codec-avro。
4. 动物园管理员:3.4.6
5. Kafka:0.10.0.0

Logstash配置文件如下所示：

input {
stdin{}
}

filter {
mutate {
remove_field => ["@timestamp","@version"]
  }
}

output {
  kafka {
topic_id => 'logstash_logs14'

codec => avro  { 
schema_uri => "/opt/logstash/bin/schema.avsc"
    }
  }
}

schema.avsc文件如下所示：

{
    "type":"record",
    "name":"myrecord",
    "fields":[
        {"name":"message","type":"string"},
        {"name":"host","type":"string"}
        ]
}

2在自己的终端启动Kafka

./bin/kafka-server-start ./etc/kafka/server.properties

3在自己的终端中启动架构注册表

./bin/schema-registry-start ./etc/schema-registry/schema-registry.properties

4从logstash目录中，运行以下命令

bin/logstash -f ./bin/logstash.conf

./bin/kafka-avro-console-consumer --zookeeper localhost:2181 --topic logstash_logs14 --from-beginning
_While consuming we get the following error:_

SLF4J: Class path contains multiple SLF4J bindings.
SLF4J: Found binding in [jar:file:/root/confluent-3.0.0/share/java/kafka-serde-tools/slf4j-log4j12-1.7.6.jar!/org/slf4j/impl/StaticLoggerBinder.class]
SLF4J: Found binding in [jar:file:/root/confluent-3.0.0/share/java/confluent-common/slf4j-log4j12-1.7.6.jar!/org/slf4j/impl/StaticLoggerBinder.class]
SLF4J: Found binding in [jar:file:/root/confluent-3.0.0/share/java/schema-registry/slf4j-log4j12-1.7.6.jar!/org/slf4j/impl/StaticLoggerBinder.class]
SLF4J: See http://www.slf4j.org/codes.html#multiple_bindings for an explanation.
SLF4J: Actual binding is of type [org.slf4j.impl.Log4jLoggerFactory]
Processed a total of 1 messages
[2016-06-08 18:42:41,627] ERROR Unknown error when running consumer:  (kafka.tools.ConsoleConsumer$:103)
org.apache.kafka.common.errors.SerializationException: Error deserializing Avro message for id -1
Caused by: org.apache.kafka.common.errors.SerializationException: Unknown magic byte!
[2016-06-08 18:42:41,627] ERROR Unknown error when running consumer:  (kafka.tools.ConsoleConsumer$:103)
org.apache.kafka.common.errors.SerializationException: Error deserializing Avro message for id -1
Caused by: org.apache.kafka.common.errors.SerializationException: Unknown magic byte!

请告诉我如何解决这个问题

谢谢，乌彭德拉

Answer 1

你是如何写/出版Kafaka的？您看到SerializationException是因为数据不是使用schema-registry（或KafkaAvroSerializer）编写的，但是当您使用schema-registry时，kafka-avro-console-consumer在内部使用schema-registry（或KafkaAvroDeserializer)，它希望数据具有某种格式（特别是 )。如果您使用kafka-avro-console-producer来编写avro数据，那么您不应该得到这个异常，或者您可以在键和值序列化器的生成器属性中设置KafkaAvroSerializer，还可以设置schema-registry-url。

Properties props = new Properties();
props.put(ProducerConfig.BOOTSTRAP_SERVERS_CONFIG, "localhost:9092");
props.put(ProducerConfig.KEY_SERIALIZER_CLASS_CONFIG,
      io.confluent.kafka.serializers.KafkaAvroSerializer.class);
props.put(ProducerConfig.VALUE_SERIALIZER_CLASS_CONFIG,
      io.confluent.kafka.serializers.KafkaAvroSerializer.class);
props.put("schema.registry.url", "http://localhost:8081");