启动spark的pyspark命令窗口时报错-pyspark.sql.utils.IllegalArgumentException: u"Error while instantiating 'org.

启动spark的pyspark命令窗口时报错

pyspark.sql.utils.IllegalArgumentException: u"Error while instantiating 'org.apache.spark.sql.hive.HiveSessionState':" 

（1）具体命令如下：

1、切换到sbin下，具体如下

/Users/a6/Applications/spark-2.1.0-bin-hadoop2.6/sbin

2、启动spark服务

xxxxxx$ sh start-all.sh 

org.apache.spark.deploy.master.Master running as process 622.  Stop it first.

localhost: org.apache.spark.deploy.worker.Worker running as process 666.  Stop it first.

3、切换到bin目录下，运行pyspark脚本

xxxxxx$cd  /Users/a6/Applications/spark-2.1.0-bin-hadoop2.6/bin

xxxxxx$ ./pyspark

    ... 105 more

Traceback (most recent call last):

  File "/Users/a6/Applications/spark-2.1.0-bin-hadoop2.6/python/pyspark/shell.py", line 43, in

    spark = SparkSession.builder\

  File "/Users/a6/Applications/spark-2.1.0-bin-hadoop2.6/python/pyspark/sql/session.py", line 179, in getOrCreate

    session._jsparkSession.sessionState().conf().setConfString(key, value)

  File "/Library/Python/2.7/site-packages/py4j-0.10.6-py2.7.egg/py4j/java_gateway.py", line 1160, in __call__

    answer, self.gateway_client, self.target_id, self.name)

  File "/Users/a6/Applications/spark-2.1.0-bin-hadoop2.6/python/pyspark/sql/utils.py", line 79, in deco

    raise IllegalArgumentException(s.split(': ', 1)[1], stackTrace)

pyspark.sql.utils.IllegalArgumentException: u"Error while instantiating 'org.apache.spark.sql.hive.HiveSessionState':" 

（2）网上有很多pyspark.sql.utils.IllegalArgumentException的异常的，但是关于u"Error while instantiating 'org.apache.spark.sql.hive.HiveSessionState':" 的页面比较少。

百度一小时，未果，认真查看报错日志，原因可能是
Caused by: ERROR XSDB6: Another instance of Derby may have already booted the database /home/hadoop/metastore_db.


于是解决方案是：重启mac，再次执行，便没有错误。
参见：
https://stackoverflow.com/questions/43551062/amazon-emr-w-spark-w-postgres-failed-to-start-database-metastore-db