问题描述
Azure Event Hub 在标准版以上就默认启用的Kafka终结点，所以可以通过Apache Kafka协议连接到Event Hub进行消息的生产和消费。通过示例代码下载到本地运行后，发现没有 Kafka Producer 的详细日志输出。当查看SDK源码中，发现使用的是 org.slf4j.Logger 输出日志，如：
但是，当运行 Producer 代码后，得到的输出取没有包含连接的详细信息，对出现连接问题的Debug没有任何帮助。
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
那么如何来输出更加详细的日志呢？
问题解决
根据日志显示， SLF4J: Failed to load class "org.slf4j.impl.StaticLoggerBinder". 明确指出是因为没有加载到 org.slf4j.impl.StaticLoggerBinder 类，因为在程序执行的过程中，必须提供实际的日志记录实现，否则SLF4J讲忽略所有日志信息，SLF4J API 通过 SLF4J 绑定与实际的日志记录实现进行通信Log4j。所以需要在pom.xml中引入 org.slf4j 的相关依赖。
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>
然后，添加上log4j的配置文件，在resources文件夹下添加名为 log4j.properties文件，内容为：
# 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
修改后的文件内容如截图所示：
修改完成，运行得到完整日志
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
参考资料
Slf4j Configuration File Example：https://examples.javacodegeeks.com/enterprise-java/slf4j/slf4j-configuration-file-example/
将 Apache Flink 与适用于 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
在微软云中国区 (Mooncake) 上实验以Apache Kafka协议方式发送/接受Event Hubs消息 (Java版) : https://www.cnblogs.com/lulight/p/14375190.html
