当启动spark-shell时,“已经注册了”WARN消息是什么?

我在windows下安装了spark / hadoop。 当我执行spark-shell,我得到这些“已经注册”的警告。

我不确定是否需要担心

C:\Users\Administrator\spark-2.2.0-bin-hadoop2.7\bin>spark-shell Using Spark's default log4j profile: org/apache/spark/log4j defaults.properties Setting default log level to "WARN". To adjust logging level use sc.setLogLevel(newLevel). For SparkR, use setLogLevel(newLevel). 17/09/24 14:29:15 WARN General: Plugin (Bundle) "org.datanucleus.store.rdbms" is already registered. Ensure you dont have multiple JAR versions of the same plugin in the classpath. The URL "file:/C:/Users/Administrator/spark-2.2.0-bin-hadoop2.7/bin/../jars/datanucleus-rdbms-3.2.9.jar" is already registered, and you are trying to registe r an identical plugin located at URL "file:/C:/Users/Administrator/spark-2.2.0-bin-hadoop2.7/jars/datanucleus-rdbms-3.2.9.jar." 17/09/24 14:29:15 WARN General: Plugin (Bundle) "org.datanucleus" is already registered. Ensure you dont have multiple JAR versions of the same plugin in the classpath. The URL "file:/C:/Users/Administrator/spark-2.2.0-bin-hadoop2.7/jars/datanucleus-core-3.2.10.jar" is already registered, and you are trying to register an identical plug in located at URL "file:/C:/Users/Administrator/spark-2.2.0-bin-hadoop2.7/bin/../jars/datanucleus-core-3.2.10.jar." 17/09/24 14:29:15 WARN General: Plugin (Bundle) "org.datanucleus.api.jdo" is already registered. Ensure you dont have multiple JAR versions of the same plugin in the cla sspath. The URL "file:/C:/Users/Administrator/spark-2.2.0-bin-hadoop2.7/jars/datanucleus-api-jdo-3.2.6.jar" is already registered, and you are trying to register an iden tical plugin located at URL "file:/C:/Users/Administrator/spark-2.2.0-bin-hadoop2.7/bin/../jars/datanucleus-api-jdo-3.2.6.jar." 17/09/24 14:29:19 WARN ObjectStore: Failed to get database global_temp, returning NoSuchObjectException Spark context Web UI available at http://173.198.192.78:4040 Spark context available as 'sc' (master = local[*], app id = local-1506277753081). Spark session available as 'spark'. Welcome to ____ __ / __/__ ___ _____/ /__ _\ \/ _ \/ _ `/ __/ '_/ /___/ .__/\_,_/_/ /_/\_\ version 2.2.0 /_/ Using Scala version 2.11.8 (Java HotSpot(TM) 64-Bit Server VM, Java 1.8.0_144) Type in expressions to have them evaluated. Type :help for more information. scala> 

这是一个警告,以确保没有在同一类路径中的多个罐子。 “已经注册”意味着类路径中的jar被注册并且应用正在尝试注册。 这是没有什么可担心的,如果你不希望看到这个设置日志级别错误。