PySpark – SparkConf
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To run a Spark application on the local/cluster, you need to set a few configurations and parameters, this is what SparkConf helps with. It provides configurations to run a Spark application. The following code block has the details of a SparkConf class for PySpark.
class pyspark.SparkConf ( loadDefaults = True, _jvm = None, _jconf = None )
Initially, we will create a SparkConf object with SparkConf(), which will load the values from spark.* Java system properties as well. Now you can set different parameters using the SparkConf object and their parameters will take priority over the system properties.
In a SparkConf class, there are setter methods, which support chaining. For example, you can write conf.setAppName(“PySpark App”).setMaster(“local”). Once we pass a SparkConf object to Apache Spark, it cannot be modified by any user.
Following are some of the most commonly used attributes of SparkConf −
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set(key, value) − To set a configuration property.
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setMaster(value) − To set the master URL.
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setAppName(value) − To set an application name.
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get(key, defaultValue=None) − To get a configuration value of a key.
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setSparkHome(value) − To set Spark installation path on worker nodes.
Let us consider the following example of using SparkConf in a PySpark program. In this example, we are setting the spark application name as PySpark App and setting the master URL for a spark application to → spark://master:7077.
The following code block has the lines, when they get added in the Python file, it sets the basic configurations for running a PySpark application.
--------------------------------------------------------------------------------------- from pyspark import SparkConf, SparkContext conf = SparkConf().setAppName("PySpark App").setMaster("spark://master:7077") sc = SparkContext(conf=conf) ---------------------------------------------------------------------------------------
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