問題描述

Azure Event Hub 在標準版以上就預設啟用的Kafka終結點，所以可以通過Apache Kafka協議連線到Event Hub進行訊息的生產和消費。通過示例程式碼下載到本地執行後，發現沒有Kafka Producer 的詳細日誌輸出。當檢視SDK原始碼中，發現使用的是org.slf4j.Logger 輸出日誌，如：

但是，當執行 Producer 程式碼後，得到的輸出取沒有包含連線的詳細資訊，對出現連線問題的Debug沒有任何幫助。

SLF4J: Failed to load class "org.slf4j.impl.StaticLoggerBinder".
SLF4J: Defaulting to no
 
-operation (NOP) logger implementation
SLF4J: See http://www.slf4j.org/codes.html#StaticLoggerBinder for further details.
Test Data #0 from thread #18
org.apache.kafka.common.errors.IllegalSaslStateException: Invalid SASL mechanism response, server may be expecting a different protocol

那麼如何來輸出更加詳細的日誌呢？

問題解決

根據日誌顯示，SLF4J: Failed to load class "org.slf4j.impl.StaticLoggerBinder".明確指出是因為沒有載入到 org.slf4j.impl.StaticLoggerBinder 類，因為在程式執行的過程中，必須提供實際的日誌記錄實現，否則SLF4J講忽略所有日誌資訊，SLF4J API 通過 SLF4J 繫結與實際的日誌記錄實現進行通訊Log4j。所以需要在pom.xml中引入 org.slf4j 的相關依賴。

在pom.xml中加入

    <dependency>
      <groupId>
 
org.slf4j</groupId>
      <artifactId>slf4j-api</artifactId>
      <version>1.7.25</version>
  </dependency>
  <dependency>
      <groupId>org.slf4j</groupId>
      <artifactId>slf4j-log4j12</artifactId>
      <version>1.7.25</version>
  </dependency>
  <dependency>
      <groupId>log4j</groupId>
      <artifactId>log4j</artifactId>
      <version>1.2.17</version>
  </dependency>
  <dependency>
    <groupId>ch.qos.logback</groupId>
    <artifactId>logback-classic</artifactId>
    <version>1.0.13</version>

然後，新增上log4j的配置檔案，在resources資料夾下新增名為 log4j.properties檔案，內容為：

# Root logger option
log4j.rootLogger=INFO, stdout
# Direct log messages to stdout
log4j.appender.stdout=org.apache.log4j.ConsoleAppender
log4j.appender.stdout.Target=System.out
log4j.appender.stdout.layout=org.apache.log4j.PatternLayout
log4j.appender.stdout.layout.ConversionPattern=%d{yyyy-MM-dd HH:mm:ss} %-5p %c{1} - %m%n

修改後的檔案內容如截圖所示：

修改完成，執行得到完整日誌

SLF4J: Class path contains multiple SLF4J bindings.
SLF4J: Found binding in [jar:file:/C:/Users/.m2/repository/org/slf4j/slf4j-log4j12/1.7.25/slf4j-log4j12-1.7.25.jar!/org/slf4j/impl/StaticLoggerBinder.class]
SLF4J: Found binding in [jar:file:/C:/Users/.m2/repository/ch/qos/logback/logback-classic/1.0.13/logback-classic-1.0.13.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]
2022-01-11 20:03:12 INFO  ProducerConfig - ProducerConfig values: 
        acks = 1
        batch.size = 16384
        bootstrap.servers = [testeventxxxxxx.servicebus.chinacloudapi.cn:9093]
        buffer.memory = 33554432
        client.id = KafkaExampleProducer
        compression.type = none
        connections.max.idle.ms = 540000
        enable.idempotence = false
        interceptor.classes = null
        key.serializer = class org.apache.kafka.common.serialization.LongSerializer
        linger.ms = 0
        max.block.ms = 60000
        max.in.flight.requests.per.connection = 5
        max.request.size = 1048576
        metadata.max.age.ms = 300000
        metric.reporters = []
        metrics.num.samples = 2
        metrics.recording.level = INFO
        metrics.sample.window.ms = 30000
        security.protocol = SASL_SSL
        send.buffer.bytes = 131072
        ssl.cipher.suites = null
        ssl.enabled.protocols = [TLSv1.2, TLSv1.1, TLSv1]
        ssl.endpoint.identification.algorithm = null
        ssl.key.password = null
        ssl.keymanager.algorithm = SunX509
        ssl.keystore.location = null
        ssl.keystore.password = null
        ssl.keystore.type = JKS
        ssl.protocol = TLS
        ssl.provider = null
        ssl.secure.random.implementation = null
        ssl.trustmanager.algorithm = PKIX
        ssl.truststore.location = null
        ssl.truststore.password = null
        ssl.truststore.type = JKS
        transaction.timeout.ms = 60000
        transactional.id = null
        value.serializer = class org.apache.kafka.common.serialization.StringSerializer

2022-01-11 20:03:16 INFO  AbstractLogin - Successfully logged in.
2022-01-11 20:03:17 INFO  AppInfoParser - Kafka version : 1.0.0
2022-01-11 20:03:17 INFO  AppInfoParser - Kafka commitId : aaa7af6d4a11b29d
2022-01-11 20:03:21 INFO  TestProducer - test java logs  : info
2022-01-11 20:03:21 ERROR TestProducer - test java logs  : error
2022-01-11 20:03:21 WARN  TestProducer - test java logs  : warn
Test Data #0 from thread #18
2022-01-11 20:03:22 ERROR NetworkClient - [Producer clientId=KafkaExampleProducer] Connection to node -1 failed authentication due to: Invalid SASL mechanism response, server may be expecting a different protocol
org.apache.kafka.common.errors.IllegalSaslStateException: Invalid SASL mechanism response, server may be expecting a different protocol
org.apache.kafka.clients.producer.KafkaProducer@47dec663

參考資料

Slf4j Configuration File Example：https://examples.javacodegeeks.com/enterprise-java/slf4j/slf4j-configuration-file-example/

將 Apache Flink 與適用於 Apache Kafka 的 Azure 事件中心配合使用:https://docs.azure.cn/zh-cn/event-hubs/event-hubs-kafka-flink-tutorial

在微軟雲中國區 (Mooncake) 上實驗以Apache Kafka協議方式傳送/接受Event Hubs訊息 (Java版) :https://www.cnblogs.com/lulight/p/14375190.html

當在複雜的環境中面臨問題，格物之道需：濁而靜之徐清，安以動之徐生。 雲中，恰是如此!