storm、hbase、kafka整合过程当中遇到的log4j冲突问题

storm、hbase、kafka整合过程当中遇到的log4j冲突问题

---》报错

SLF4J: Detected both log4j-over-slf4j.jar AND slf4j-log4j12.jar on the class path, preempting StackOverflowError.

SLF4J: See also http://www.slf4j.org/codes.html#log4jDelegationLoop for more details.

10059 [Thread-15-KafkaSpout] ERROR backtype.storm.util - Async loop died!

java.lang.NoClassDefFoundError: Could not initialize class org.apache.log4j.Log4jLoggerFactory

at org.apache.log4j.Logger.getLogger(Logger.java:39) ~[log4j-over-slf4j-1.6.6.jar:1.6.6]

at kafka.utils.Logging$class.logger(Logging.scala:24) ~[kafka_2.11-0.8.2.1.jar:na]

---》缘由

log4j-over-slf4j.jar AND slf4j-log4j12.jar 循环调用冲突了，再进一步缘由是kafka、hbase中用的是log4j。

---》解决方法

* 方案一：把storm中的log4j-over-slf4j 依赖排除；

<dependency>
			<groupId>org.apache.storm</groupId>
			<artifactId>storm-core</artifactId>
			<version>0.9.5</version>
			<scope>provided</scope>
			<exclusions>
				<exclusion>
					<groupId>org.slf4j</groupId>
					<artifactId>log4j-over-slf4j</artifactId>
				</exclusion>
			</exclusions>
		</dependency>
			     	
		<dependency>
			<groupId>org.apache.kafka</groupId>
			<artifactId>kafka_2.11</artifactId>
			<version>0.8.2.1</version>
		</dependency>
		
		<dependency>
			<groupId>org.apache.hbase</groupId>
			<artifactId>hbase-client</artifactId>
			<version>1.0.1.1</version>
		</dependency>

* 方案二：把kafka和hbase中的slf4j-log4j12 依赖排除；

<dependency>
			<groupId>org.apache.storm</groupId>
			<artifactId>storm-core</artifactId>
			<version>0.9.5</version>
			<scope>provided</scope>
			<exclusions>
				<exclusion>
					<groupId>org.slf4j</groupId>
					<artifactId>log4j-over-slf4j</artifactId>
				</exclusion>
				<exclusion>
					<groupId>org.slf4j</groupId>
					<artifactId>slf4j-api</artifactId>
				</exclusion>
			</exclusions>
			 -->
		</dependency>
			     	
		<dependency>
			<groupId>org.apache.kafka</groupId>
			<artifactId>kafka_2.11</artifactId>
			<version>0.8.2.1</version>
			<exclusions>
		        <exclusion>
		            <groupId>org.slf4j</groupId>
		            <artifactId>slf4j-log4j12</artifactId>
		        </exclusion>
		        <exclusion>
		            <groupId>log4j</groupId>
		            <artifactId>log4j</artifactId>
		        </exclusion>
		    </exclusions>
		</dependency>
		
		<dependency>
			<groupId>org.apache.hbase</groupId>
			<artifactId>hbase-client</artifactId>
			<version>1.0.1.1</version>
			<exclusions>
		        <exclusion>
		            <groupId>org.slf4j</groupId>
		            <artifactId>slf4j-log4j12</artifactId>
		        </exclusion>
		        <exclusion>
		            <groupId>log4j</groupId>
		            <artifactId>log4j</artifactId>
		        </exclusion>
		    </exclusions>			
		</dependency>
<!-- 
		<dependency>
			<groupId>org.apache.hbase</groupId>
			<artifactId>hbase-common</artifactId>
			<version>1.0.1.1</version>
		</dependency>
		 -->
		<dependency>
			<groupId>redis.clients</groupId>
			<artifactId>jedis</artifactId>
			<version>2.7.0</version>
		</dependency>

* 采用方案二便于集群发布

* storm的日志时采用的 SLF4J和Logback日志框架，因此本身写的storm代码统一使用 slf4j 的包，能够避免大多数包冲突问题。

import org.slf4j.Logger;

import org.slf4j.LoggerFactory;

public class MyBolt {

private static final Logger LOG = LoggerFactory

.getLogger(MyBolt.class);

}