SLF4J：类路径包含多个 SLF4J 绑定。 - 阿帕奇卡夫卡 3.1

Question

我正在尝试从 git 源运行 Apache Kafka，但我收到

multiple SLF4J bindings

警告，这会在使用 docker 容器时导致失败。

根据文档；

git clone --depth 1 --branch 3.1 https://github.com/apache/kafka.git

cd kafka

./gradlew clean
./gradlew dependencyUpdates
./gradlew jar -PscalaVersion=2.13.6

export UUID=$(./bin/kafka-storage.sh random-uuid); ./bin/kafka-storage.sh format -t $UUID -c ./config/kraft/server.properties

结果我得到：

SLF4J: Class path contains multiple SLF4J bindings.
SLF4J: Found binding in [jar:file:/home/ubuntu/kafka/core/build/dependant-libs-2.13.6/slf4j-log4j12-1.7.30.jar!/org/slf4j/impl/StaticLoggerBinder.class]
SLF4J: Found binding in [jar:file:/home/ubuntu/kafka/tools/build/dependant-libs-2.13.6/slf4j-log4j12-1.7.30.jar!/org/slf4j/impl/StaticLoggerBinder.class]
SLF4J: Found binding in [jar:file:/home/ubuntu/kafka/trogdor/build/dependant-libs-2.13.6/slf4j-log4j12-1.7.30.jar!/org/slf4j/impl/StaticLoggerBinder.class]
SLF4J: Found binding in [jar:file:/home/ubuntu/kafka/connect/api/build/dependant-libs/slf4j-log4j12-1.7.30.jar!/org/slf4j/impl/StaticLoggerBinder.class]
SLF4J: Found binding in [jar:file:/home/ubuntu/kafka/connect/transforms/build/dependant-libs/slf4j-log4j12-1.7.30.jar!/org/slf4j/impl/StaticLoggerBinder.class]
SLF4J: Found binding in [jar:file:/home/ubuntu/kafka/connect/runtime/build/dependant-libs/slf4j-log4j12-1.7.30.jar!/org/slf4j/impl/StaticLoggerBinder.class]
SLF4J: Found binding in [jar:file:/home/ubuntu/kafka/connect/file/build/dependant-libs/slf4j-log4j12-1.7.30.jar!/org/slf4j/impl/StaticLoggerBinder.class]
SLF4J: Found binding in [jar:file:/home/ubuntu/kafka/connect/mirror/build/dependant-libs/slf4j-log4j12-1.7.30.jar!/org/slf4j/impl/StaticLoggerBinder.class]
SLF4J: Found binding in [jar:file:/home/ubuntu/kafka/connect/mirror-client/build/dependant-libs/slf4j-log4j12-1.7.30.jar!/org/slf4j/impl/StaticLoggerBinder.class]
SLF4J: Found binding in [jar:file:/home/ubuntu/kafka/connect/json/build/dependant-libs/slf4j-log4j12-1.7.30.jar!/org/slf4j/impl/StaticLoggerBinder.class]
SLF4J: Found binding in [jar:file:/home/ubuntu/kafka/connect/basic-auth-extension/build/dependant-libs/slf4j-log4j12-1.7.30.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]
SLF4J: Class path contains multiple SLF4J bindings.
SLF4J: Found binding in [jar:file:/home/ubuntu/kafka/core/build/dependant-libs-2.13.6/slf4j-log4j12-1.7.30.jar!/org/slf4j/impl/StaticLoggerBinder.class]
SLF4J: Found binding in [jar:file:/home/ubuntu/kafka/tools/build/dependant-libs-2.13.6/slf4j-log4j12-1.7.30.jar!/org/slf4j/impl/StaticLoggerBinder.class]
SLF4J: Found binding in [jar:file:/home/ubuntu/kafka/trogdor/build/dependant-libs-2.13.6/slf4j-log4j12-1.7.30.jar!/org/slf4j/impl/StaticLoggerBinder.class]
SLF4J: Found binding in [jar:file:/home/ubuntu/kafka/connect/api/build/dependant-libs/slf4j-log4j12-1.7.30.jar!/org/slf4j/impl/StaticLoggerBinder.class]
SLF4J: Found binding in [jar:file:/home/ubuntu/kafka/connect/transforms/build/dependant-libs/slf4j-log4j12-1.7.30.jar!/org/slf4j/impl/StaticLoggerBinder.class]
SLF4J: Found binding in [jar:file:/home/ubuntu/kafka/connect/runtime/build/dependant-libs/slf4j-log4j12-1.7.30.jar!/org/slf4j/impl/StaticLoggerBinder.class]
SLF4J: Found binding in [jar:file:/home/ubuntu/kafka/connect/file/build/dependant-libs/slf4j-log4j12-1.7.30.jar!/org/slf4j/impl/StaticLoggerBinder.class]
SLF4J: Found binding in [jar:file:/home/ubuntu/kafka/connect/mirror/build/dependant-libs/slf4j-log4j12-1.7.30.jar!/org/slf4j/impl/StaticLoggerBinder.class]
SLF4J: Found binding in [jar:file:/home/ubuntu/kafka/connect/mirror-client/build/dependant-libs/slf4j-log4j12-1.7.30.jar!/org/slf4j/impl/StaticLoggerBinder.class]
SLF4J: Found binding in [jar:file:/home/ubuntu/kafka/connect/json/build/dependant-libs/slf4j-log4j12-1.7.30.jar!/org/slf4j/impl/StaticLoggerBinder.class]
SLF4J: Found binding in [jar:file:/home/ubuntu/kafka/connect/basic-auth-extension/build/dependant-libs/slf4j-log4j12-1.7.30.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]

关于如何解决这个问题有什么想法吗？

Answer 1

这里唯一的问题是

kafka-storage

脚本多次加载同一个jar。

版本没有不同，所以没有实际问题。

bin/kafka-run-class

脚本应该进行适当的类路径隔离

您不需要 Gradle 来运行 KRaft 模式

Answer 2

我对这个问题的想法是你必须删除目录中的多个jar文件：/home/ubuntu/kafka/* 与 SLF4J 相关：slf4j-log4j12-1.7.30.jar（当前在您的情况下）

注意：保留这个东西实际上并不会阻止你运行 Kafka 服务器，但是每次你想记录与 Kafka 相关的内容时，都会弹出这个错误，造成很大的烦恼。

就我而言，我删除了kafka中的所有其他slf4j文件夹，除了/home/ubuntu/kafka/tools/build/中的文件夹，它解决了我的问题！