You are viewing a plain text version of this content. The canonical link for it is here.
Posted to issues@spark.apache.org by "Hyukjin Kwon (JIRA)" <ji...@apache.org> on 2019/05/21 04:38:12 UTC
[jira] [Resolved] (SPARK-16262) Impossible to remake new
SparkContext using SparkSession API in Pyspark
[ https://issues.apache.org/jira/browse/SPARK-16262?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel ]
Hyukjin Kwon resolved SPARK-16262.
----------------------------------
Resolution: Incomplete
> Impossible to remake new SparkContext using SparkSession API in Pyspark
> -----------------------------------------------------------------------
>
> Key: SPARK-16262
> URL: https://issues.apache.org/jira/browse/SPARK-16262
> Project: Spark
> Issue Type: Improvement
> Components: PySpark
> Reporter: Vladimir Feinberg
> Priority: Minor
> Labels: bulk-closed
>
> There are multiple use cases where one might like to be able to stop and re-start a {{SparkSession}}: configuration changes or modular testing. The following code demonstrates that without clearing a hidden global {{SparkSession._instantiatedContext = None}} it is impossible to re-create a new Spark session after stopping one in the same process:
> {code}
> >>> from pyspark.sql import SparkSession
> >>> spark = SparkSession.builder.getOrCreate()
> 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).
> 16/06/28 11:28:10 WARN NativeCodeLoader: Unable to load native-hadoop library for your platform... using builtin-java classes where applicable
> 16/06/28 11:28:10 WARN Utils: Your hostname, vlad-databricks resolves to a loopback address: 127.0.1.1; using 192.168.3.166 instead (on interface enp0s31f6)
> 16/06/28 11:28:10 WARN Utils: Set SPARK_LOCAL_IP if you need to bind to another address
> >>> spark.stop()
> >>> spark = SparkSession.builder.getOrCreate()
> >>> spark.createDataFrame([(1,)])
> Traceback (most recent call last):
> File "<stdin>", line 1, in <module>
> File "pyspark/sql/session.py", line 514, in createDataFrame
> rdd, schema = self._createFromLocal(map(prepare, data), schema)
> File "pyspark/sql/session.py", line 394, in _createFromLocal
> return self._sc.parallelize(data), schema
> File "pyspark/context.py", line 410, in parallelize
> numSlices = int(numSlices) if numSlices is not None else self.defaultParallelism
> File "pyspark/context.py", line 346, in defaultParallelism
> return self._jsc.sc().defaultParallelism()
> AttributeError: 'NoneType' object has no attribute 'sc'
> {code}
--
This message was sent by Atlassian JIRA
(v7.6.3#76005)
---------------------------------------------------------------------
To unsubscribe, e-mail: issues-unsubscribe@spark.apache.org
For additional commands, e-mail: issues-help@spark.apache.org