Running Apache Spark 3.4 applications
You can run Apache Spark 3 applications locally or distributed across a cluster, either by using an interactive shell or by submitting an application. Running Spark applications interactively is commonly performed during the data-exploration phase and for ad hoc analysis.
Unsupported connectors
- SparkR
Limitations of Spark in CDP
spark.sql.orc.compression.codec
config doesn't acceptzsdt
value.
Canary test for pyspark command
The following example shows a simple pyspark
session that refers to the
SparkContext, calls the collect()
function which runs a Spark 3 job, and
writes data to HDFS. This sequence of operations helps to check if there are obvious
configuration issues that prevent Spark 3 jobs from working at all. For the HDFS path for
the output directory, substitute a path that exists on your own system.
$ hdfs dfs -mkdir /user/jdoe/spark
$ pyspark
...
SparkSession available as 'spark'.
>>> strings = ["one","two","three"]
>>> s2 = sc.parallelize(strings)
>>> s3 = s2.map(lambda word: word.upper())
>>> s3.collect()
['ONE', 'TWO', 'THREE']
>>> s3.saveAsTextFile('hdfs:///user/jdoe/spark/canary_test')
>>> quit()
$ hdfs dfs -ls /user/jdoe/spark
Found 1 items
drwxr-xr-x - jdoe spark-users 0 2016-08-26 14:41 /user/jdoe/spark/canary_test
$ hdfs dfs -ls /user/jdoe/spark/canary_test
Found 3 items
-rw-r--r-- 3 jdoe spark-users 0 2016-08-26 14:41 /user/jdoe/spark/canary_test/_SUCCESS
-rw-r--r-- 3 jdoe spark-users 4 2016-08-26 14:41 /user/jdoe/spark/canary_test/part-00000
-rw-r--r-- 3 jdoe spark-users 10 2016-08-26 14:41 /user/jdoe/spark/canary_test/part-00001
$ hdfs dfs -cat /user/jdoe/spark/canary_test/part-00000
ONE
$ hdfs dfs -cat /user/jdoe/spark/canary_test/part-00001
TWO
THREE
Fetching Spark 3 Maven Dependencies
The Maven coordinates are a combination of groupId, artifactId and version. The groupId
and artifactId are the same as for the upstream Apache Spark project. For example, for
spark-core
, groupId is org.apache.spark
, and artifactId
is spark-core_2.12
, both the same as the upstream project. The version is
different for the Cloudera packaging, it contains the upstream Spark version as well as the
CDP version: [**artifactId***]-[***UPSTREAM SPARK
VERSION***].[***CDP VERSION***]-[***CDP BUILD
NUMBER***]
. For example,
spark-core_2.12-3.3.0.7.2.16.0-123
.
Accessing the Spark 3 History Server
The Spark 3 history server is available on port 18089, rather than port 18088 as with the Spark 2 history server.