有人知道是什么让spark花这么长时间来装填它的外壳吗？sparkshell命令为我加载sparkshell大约需要6分钟。我想这不正常。我在一个hadoop集群上运行这个程序，这个集群由4个raspberrypi4组成，内存为4gb。以下是Spark壳加载，

Java HotSpot(TM) Server VM warning: You have loaded library /opt/hadoop/lib/native/libhadoop.so.1.0.0 which might have disabled stack guard. The VM will try to fix the stack guard now.

It's highly recommended that you fix the library with 'execstack -c <libfile>', or link it with '-z noexecstack'.
2020-07-10 09:05:07,903 WARN util.NativeCodeLoader: Unable to load native-hadoop library for your platform... using builtin-java classes where applicable

Setting default log level to "WARN".
To adjust logging level use sc.setLogLevel(newLevel). For SparkR, use setLogLevel(newLevel).

2020-07-10 09:05:47,663 WARN yarn.Client: Neither spark.yarn.jars nor spark.yarn.archive is set, falling back to uploading libraries under SPARK_HOME.

Spark context Web UI available at http://pi1:4040

Spark context available as 'sc' (master = yarn, app id = application_1594337770867_0003).

Spark session available as 'spark'.

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