tomcat服务器出现该异常，一直报该异常，无法正常打印日志，
AsyncLogger error handling event seq=17812, value='Logger=org.apache.zookeeper.ClientCnxn Level=WARN Message=Session 0x10005f9db9ea4f7 for server 192.168.160.58/192.168.160.58:2181, unexpected error, closing socket connection and attempting reconnect':
java.lang.NoClassDefFoundError: org/apache/logging/log4j/core/impl/ThrowableProxy
解决方法：
关闭tomcat，并通过ps -ef|grep tomcat查看是否有tomcat的服务在运行，如果有通过kill -9 pid全部杀掉tomcat服务，然后重启tomcat后正常。