sl4j version conflicts in gradle with Storm 1.0.1 and elasticsearch 5.2

Question

We are facing sl4j version conflicts in gradle with Storm 1.0.1 and elasticsearch 5.2.

We found that the ElasticSearch needs bridge log4j-to-slf4j so that we can use desired loggers. Here we are trying to use logback-classic with slf4j.

The dependencies are defined as below:

dependencies {
    compile 'org.slf4j:slf4j-api:1.7.21'
    compile 'org.apache.logging.log4j:log4j-to-slf4j:2.6.2'
    compile 'ch.qos.logback:logback-classic:1.1.10'
    provided ('org.apache.storm:storm-core:1.0.1') {
        exclude(group: 'org.slf4j', module: 'slf4j-api')
    }
    compile 'org.elasticsearch:elasticsearch:5.2.0'
    compile 'org.elasticsearch.client:x-pack-transport:5.2.0'
}

To resolve this I tried to exclude the slf4j from storm-core and add the same later as below:

configurations.all {
    resolutionStrategy {
        eachDependency { DependencyResolveDetails dependencyResolveDetails ->
            final requestedDependency = dependencyResolveDetails.requested
            if (requestedDependency.group == 'org.slf4j' && requestedDependency.name == 'slf4j-api') {
                requestedDependency.setVersion "1.7.7"
            }
         }
    }
}

But when topology is submitted we get error : SLF4J: Class path contains multiple SLF4J bindings. SLF4J: Found binding in [jar:file:/Users/gauthamr05/Documents/Apps/Storm/apache-storm-1.0.1/lib/log4j-slf4j-impl-2.1.jar!/org/slf4j/impl/StaticLoggerBinder.class] SLF4J: Found binding in [jar:file:/Users/gauthamr05/Documents/workspace/xyz_app/build/libs/FullIndexing.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.apache.logging.slf4j.Log4jLoggerFactory] Exception in thread "main" java.lang.StackOverflowError at org.apache.logging.log4j.spi.LoggerRegistry.getOrCreateInnerMap(LoggerRegistry.java:140) at org.apache.logging.log4j.spi.LoggerRegistry.hasLogger(LoggerRegistry.java:154) at org.apache.logging.slf4j.SLF4JLoggerContext.getLogger(SLF4JLoggerContext.java:38) at org.apache.logging.slf4j.Log4jLoggerFactory.newLogger(Log4jLoggerFactory.java:37) at org.apache.logging.slf4j.Log4jLoggerFactory.newLogger(Log4jLoggerFactory.java:29) at org.apache.logging.log4j.spi.AbstractLoggerAdapter.getLogger(AbstractLoggerAdapter.java:47) at org.apache.logging.slf4j.Log4jLoggerFactory.getLogger(Log4jLoggerFactory.java:29) at org.slf4j.LoggerFactory.getLogger(LoggerFactory.java:277)

lance-java · Answer 1 · 2017-02-10T11:47:25.760

As the exception states, there's two jars containing StaticLoggerBinder.class.

/Users/gauthamr05/Documents/Apps/Storm/apache-storm-1.0.1/lib/log4j-slf4j-impl-2.1.jar
/Users/gauthamr05/Documents/workspace/xyz_app/build/libs/FullIndexing.jar

Question: Is xyz_app/build/libs/FullIndexing.jar one of your own projects?

If it is your own jar, I'm taking a bit of a guess here, but I'm guessing that org/slf4j/impl/StaticLoggerBinder.java is packed inside one of the jars on your classpath. There's a wierd default of javac where it will compile any .java files found in jars on your classpath. This can be switched off by

compileJava.options.compilerArgs << '-implicit:none'

See here and here

score 0 · Answer 2 · answered Feb 20 '17 at 08:51

Found a way to shadow the log4j classes in the final jar.

Following are the configurations:

apply plugin: 'com.github.johnrengelman.shadow'

subprojects {
    shadowJar
}

dependencies {
    compile 'org.slf4j:slf4j-api:1.7.22'
    compile 'ch.qos.logback:logback-classic:1.1.10'

    compileOnly("org.apache.storm:storm-core:1.0.1") {
        exclude module: "log4j-slf4j-impl"
        exclude module: "slf4j-api"
        exclude module: "log4j-to-slf4j"
    }

    // ElasticSearch and X-Pack
    compile 'org.elasticsearch:elasticsearch:5.2.0'
    compile 'org.elasticsearch.client:x-pack-transport:5.2.0'

    compile 'org.apache.logging.log4j:log4j-api:2.7'
    compile 'org.apache.logging.log4j:log4j-core:2.7'
}

shadowJar {
    relocate 'org.apache.logging.log4j', 'gautham.elasticsearch.org.apache.logging.log4j'

    zip64 true
    transform(ServiceFileTransformer) {
        path = 'META-INF/vesta*'
    }

    manifest {
        attributes 'Implementation-Title': 'Storm Topology',
            'Implementation-Version': 1.0,
            'Main-Class': 'com.gautham.topology.StormTopology'
    }

    baseName = 'StormTopology'

    mergeServiceFiles()

    exclude "META-INF/*.SF"
    exclude 'META-INF/*.DSA'
    exclude 'META-INF/*.RSA'
    exclude "LICENSE*"
}

sl4j version conflicts in gradle with Storm 1.0.1 and elasticsearch 5.2

2 Answers2