Difference between revisions of "Spark"

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−
[[Category:Software]][[Category:spark]][[Category:hadoop]]
+
[[Category:Software]][[Category:Utility]]
 
{|<!--CONFIGURATION: REQUIRED-->
 
{|<!--CONFIGURATION: REQUIRED-->
 
|{{#vardefine:app|spark}}
 
|{{#vardefine:app|spark}}
Line 6: Line 6:
 
|{{#vardefine:conf|}}          <!--CONFIGURATION-->
 
|{{#vardefine:conf|}}          <!--CONFIGURATION-->
 
|{{#vardefine:exe|}}            <!--ADDITIONAL INFO-->
 
|{{#vardefine:exe|}}            <!--ADDITIONAL INFO-->
−
|{{#vardefine:job|}}            <!--JOB SCRIPTS-->
+
|{{#vardefine:job|1}}            <!--JOB SCRIPTS-->
 
|{{#vardefine:policy|}}        <!--POLICY-->
 
|{{#vardefine:policy|}}        <!--POLICY-->
 
|{{#vardefine:testing|}}      <!--PROFILING-->
 
|{{#vardefine:testing|}}      <!--PROFILING-->
Line 24: Line 24:
 
Run <code>module spider {{#var:app}}</code> to find out what environment modules are available for this application.
 
Run <code>module spider {{#var:app}}</code> to find out what environment modules are available for this application.
 
==System Variables==
 
==System Variables==
−
* HPC_{{#uppercase:{{#var:app}}}}_DIR - installation directory
+
* HPC_{{uc:{{#var:app}}}}_DIR - installation directory
−
* HPC_{{#uppercase:{{#var:app}}}}_BIN - executable directory
+
* HPC_{{uc:{{#var:app}}}}_BIN - executable directory
−
* HPC_{{#uppercase:{{#var:app}}}}_SLURM - SLURM job script examples
+
* HPC_{{uc:{{#var:app}}}}_SLURM - SLURM job script examples
 
* SPARK_HOME - examples directory
 
* SPARK_HOME - examples directory
  
−
==Running Spark in HiperGator==
+
==Running Spark on HiperGator==
−
To run your Spark jobs in HiperGator, first, a Spark cluster should be created in HiperGator via SLURM. This section shows a simple example how to create a Spark cluster in HiperGator and how to submit your Spark jobs into the cluster. For details about running Spark jobs in HiperGaotr, please refer to [https://help.rc.ufl.edu/doc/Spark_Workshop Spark Workshop]. For Spark parameters used in this section, please refer to [https://spark.apache.org/ Spark's homepage].
+
To run your Spark jobs on HiperGator, two separate steps are required:
  
−
===Spark cluster in HiperGator===
+
# Create a Spark cluster on HiperGator via SLURM. This section "Spark Cluster on HiPerGator" below shows a simple example how to create a Spark cluster on HiperGator.
 +
# Submit your job to your Spark cluster.  You can do this either interactively at the command line ("Spark Interactive Job" section below) or by submitting a a batch job ("Spark Batch Job" section below)
 +
 
 +
For details about running Spark jobs on HiPerGator, please refer to [https://help.rc.ufl.edu/doc/Spark_Workshop Spark Workshop]. For Spark parameters used in this section, please refer to [https://spark.apache.org/ Spark's homepage].
 +
 
 +
===Spark cluster on HiperGator===
 
<div class="mw-collapsible mw-collapsed" style="width:70%; padding: 5px; border: 1px solid gray;">
 
<div class="mw-collapsible mw-collapsed" style="width:70%; padding: 5px; border: 1px solid gray;">
 
''Expand this section to view instructions for creating a spark cluster in HiperGator.''
 
''Expand this section to view instructions for creating a spark cluster in HiperGator.''
 
<div class="mw-collapsible-content" style="padding: 5px;">
 
<div class="mw-collapsible-content" style="padding: 5px;">
−
It is assumed that the file name of the SLURM script is spark-cluster.sh for one-worker node Spark cluster.
+
It is assumed that spark-local-cluster.sh is the file name of the SLURM job script for one-worker node Spark cluster in this section.
−
Set SLURM parameters for Spark cluster.
+
Set SLURM parameters for Spark cluster. spark-local-cluster.sh is available on "Spark_Job_Scripts" page below.
 +
<pre>
 
  #!/bin/bash
 
  #!/bin/bash
−
  #filename: spark-cluster.sh
+
  #filename: spark-local-cluster.sh
 
  #SBATCH --job-name=spark_cluster
 
  #SBATCH --job-name=spark_cluster
 
  #SBATCH --nodes=1 # nodes allocated to the job
 
  #SBATCH --nodes=1 # nodes allocated to the job
Line 50: Line 56:
 
  module load spark
 
  module load spark
  
−
Set Spark parameters for Spark cluster
+
## Set Spark parameters for Spark cluster
 
  export SPARK_LOCAL_DIRS=$HOME/spark/tmp
 
  export SPARK_LOCAL_DIRS=$HOME/spark/tmp
 
  export SPARK_WORKER_DIR=$SPARK_LOCAL_DIRS
 
  export SPARK_WORKER_DIR=$SPARK_LOCAL_DIRS
Line 58: Line 64:
 
  export SPARK_NO_DAEMONIZE=true
 
  export SPARK_NO_DAEMONIZE=true
 
  export SPARK_LOG_DIR=$SPARK_LOCAL_DIRS
 
  export SPARK_LOG_DIR=$SPARK_LOCAL_DIRS
−
#export SPARK_CONF_DIR=$SPARK_LOCAL_DIRS
+
 
 
  mkdir -p $SPARK_LOCAL_DIRS
 
  mkdir -p $SPARK_LOCAL_DIRS
  
−
Set Spark Master and Workers
+
##Set Spark Master and Workers
 
  MASTER_HOST=$(scontrol show hostname $SLURM_NODELIST | head -n 1)
 
  MASTER_HOST=$(scontrol show hostname $SLURM_NODELIST | head -n 1)
 
  export SPARK_MASTER_NODE=$(host $MASTER_HOST | head -1 | cut -d ' ' -f 4)
 
  export SPARK_MASTER_NODE=$(host $MASTER_HOST | head -1 | cut -d ' ' -f 4)
 
  export MAX_SLAVES=$(expr $SLURM_JOB_NUM_NODES - 1)
 
  export MAX_SLAVES=$(expr $SLURM_JOB_NUM_NODES - 1)
−
  # for starting spark master
+
 
 +
  ## for starting spark master
 
  $SPARK_HOME/sbin/start-master.sh &  
 
  $SPARK_HOME/sbin/start-master.sh &  
−
  # use spark defaults for worker resources (all mem -1 GB, all cores) since using exclusive
+
 
−
  #for starting spark worker
+
  ## use spark defaults for worker resources (all mem -1 GB, all cores) since using exclusive
 +
  ## for starting spark worker
 
  $SPARK_HOME/sbin/start-slave.sh spark://$SPARK_MASTER_NODE:$SPARK_MASTER_PORT
 
  $SPARK_HOME/sbin/start-slave.sh spark://$SPARK_MASTER_NODE:$SPARK_MASTER_PORT
 +
</pre>
 +
 +
Submit the SLURM job script to HiperGator
 +
sbatch spark-local-cluster.sh
 +
 +
Check the Spark master launched.
 +
grep "Starting Spark master" spark_cluster.err
 +
 +
This grep command above should end up with information like
 +
18/03/13 14:53:23 INFO Master: Starting Spark master at spark://c29a-s42.ufhpc:7077
 +
 +
Check the Spark worker launched.
 +
grep "Starting Spark worker" spark_cluster.err
  
−
# Submit the SLURM job script to HiperGator
+
This grep command above should end up with information like
 +
18/03/13 14:53:24 INFO Worker: Starting Spark worker 172.16.194.59:42418 with 16 cores, 124.3 GB RAM
 
</div>
 
</div>
 
</div>
 
</div>
  
−
===Submit Spark jobs===
+
===Spark interactive job===
 
<div class="mw-collapsible mw-collapsed" style="width:70%; padding: 5px; border: 1px solid gray;">
 
<div class="mw-collapsible mw-collapsed" style="width:70%; padding: 5px; border: 1px solid gray;">
 
''Expand this section to view instructions for starting preset applications without a job script.''
 
''Expand this section to view instructions for starting preset applications without a job script.''
 
<div class="mw-collapsible-content" style="padding: 5px;">
 
<div class="mw-collapsible-content" style="padding: 5px;">
 +
Spark supports interactive job submission through the interactive shells.
 +
 +
;Spark interactive shell in Scalar (spark-shell)
 +
First, load spark module in the terminal where you want to submit a spark job.
 +
module load spark
 +
 +
Get the location of the Spark master to connect to it through the interactive shell
 +
SPARK_MASTER=$(grep "Starting Spark master" *.err | cut -d " " -f 9)
 +
 +
Connect to the master using the Spark interactive shell in scalar
 +
spark-shell --master $SPARK_MASTER
 +
 +
;Spark interactive shell in Python (pyspark)
 +
Load spark module in the terminal where you want to submit a spark job.
 +
module load spark
 +
 +
Get the location of the Spark master to connect to it through the interactive shell
 +
SPARK_MASTER=$(grep "Starting Spark master" *.err | cut -d " " -f 9)
 +
 +
Connect to the master using the Spark interactive shell in scalar
 +
pyspark --master $SPARK_MASTER
 +
 +
;Example - PI estimation via pyspark
 +
SPARK_MASTER=$(grep "Starting Spark master" *.err | cut -d " " -f 9)
 +
pyspark --master $SPARK_MASTER
 +
[[File:Pi_with_pyspark.png]]
 +
;Example - Pi estimation from file with pyspark
 +
As of Spark 2.0., Spark interactive shell in python does not load python files to run python application. Instead, “PYTHONSTARTUP”, a python environmental variable can be used to run python script with pyspark, which executes the python script before an interactive shell starts.
 +
 +
SPARK_MASTER=$(grep "Starting Spark master" *.err | cut -d " " -f 9)
 +
PYTHONSTARTUP=pi_with_pythonstartup.py pyspark --master $SPARK_MASTER
 +
 +
pi_with_pythonstartup.py script is avaialble on "Spark_Job_Scripts" page below.
 +
</div>
 +
</div>
 +
 +
===Spark batch job===
 +
<div class="mw-collapsible mw-collapsed" style="width:70%; padding: 5px; border: 1px solid gray;">
 +
''Expand this section to view instructions for starting preset applications without a job script.''
 +
<div class="mw-collapsible-content" style="padding: 5px;">
 +
Spark supports batch job submission through spark-submit which provides unified interface for Spark jobs
 +
$SPARK_HOME/bin/spark-submit  \
 +
              --class <main-class>  --master <master-url> \
 +
              --deploy-mode <deploy-mode>  --conf <key>=<value>  \
 +
            ... # other options  <application-jar>  [application-arguments]
 +
 +
--class: The entry point for your application (e.g. org.apache.spark.examples.SparkPi)
 +
--master: The master URL for the cluster (e.g. spark://123.45.67.890:7077)
 +
--deploy-mode: Whether to deploy your driver on the worker nodes (cluster) or locally as an external client (client) (default: client)
 +
--conf: Arbitrary Spark configuration property in key=value format. For values that contain spaces wrap “key=value” in quotes (as shown).
 +
<application-jar>: Path to a bundled jar including your application and all dependencies. The URL must be globally visible inside of your cluster,
 +
  for instance, an hdfs:// path or a file:// path that is present on all nodes.
 +
<application-arguments>: Arguments passed to the main method of your main class, if any
 +
 +
For further details about spark-submit, refer to https://spark.apache.org/docs/2.2.0/submitting-applications.html.
 +
 +
;Example - Pi estimation via Spark-submit
 +
SPARK_MASTER=$(grep "Starting Spark master" *.err | cut -d " " -f 9)
 +
spark-submit --master $SPARK_MASTER $SPARK_HOME/examples/src/main/python/pi.py 10
 +
[[File:Pi_spark-submit.png]]
  
−
*Spark interactive shells in Scalar and Python
 
−
* Spark interactive shell in Scalar (spark-shell)
 
−
* Spark interactive shell in Python (pyspark)
 
−
# Pi estimation in pyspark
 
−
# Pi estimation from file with pyspark
 
−
* Spark-submit
 
−
# Pi estimation
 
−
# Wordcount
 
 
</div>
 
</div>
 
</div>
 
</div>
Line 103: Line 177:
 
<!--Job Scripts-->
 
<!--Job Scripts-->
 
{{#if: {{#var: job}}|==Job Script Examples==
 
{{#if: {{#var: job}}|==Job Script Examples==
−
See the [[{{PAGENAME}}_Job_Scripts]] page for {{#var: app}} Job script examples.
+
<div class="mw-collapsible mw-collapsed" style="width:70%; padding: 5px; border: 1px solid gray;">
 +
''Expand this section to view spark-local-cluster.sh''
 +
<div class="mw-collapsible-content" style="padding: 5px;">
 +
<source lang=bash>
 +
#!/bin/bash
 +
#filename: spark-local-cluster.sh
 +
 
 +
#SBATCH --job-name=spark_cluster
 +
#SBATCH --nodes=1 # nodes allocated to the job
 +
#SBATCH --cpus-per-task=16 # the number of CPUs allocated per task
 +
#SBATCH --exclusive # not sharing of allocated nodes with other running jobs
 +
#SBATCH --time=03:00:00
 +
#SBATCH --output=spark_cluster.log
 +
#SBATCH --error=spark_cluster.err
 +
 
 +
###SBATCH --ntasks= # tasks to be created for the job
 +
###SBATCH --ntasks-per-core= # max number of tasks per allocated core
 +
###SBATCH --ntasks-per-node= # max number of tasks per allocated node
 +
###SBATCH --mail-type=END,FAIL
 +
###SBATCH --mail-user=<yourID>@ufl.edu
 +
 
 +
module load spark
 +
### Set Spark variables
 +
export SPARK_LOCAL_DIRS=$HOME/spark/tmp
 +
export SPARK_WORKER_DIR=$SPARK_LOCAL_DIRS
 +
export SPARK_WORKER_CORES=$SLURM_CPUS_PER_TASK
 +
export SPARK_MASTER_PORT=7077
 +
export SPARK_MASTER_WEBUI_PORT=8080
 +
export SPARK_NO_DAEMONIZE=true
 +
export SPARK_LOG_DIR=$SPARK_LOCAL_DIRS
 +
#export SPARK_CONF_DIR=$SPARK_LOCAL_DIRS
 +
mkdir -p $SPARK_LOCAL_DIRS
 +
 
 +
MASTER_HOST=$(scontrol show hostname $SLURM_NODELIST | head -n 1)
 +
export SPARK_MASTER_NODE=$(host $MASTER_HOST | head -1 | cut -d ' ' -f 4)
 +
export MAX_SLAVES=$(expr $SLURM_JOB_NUM_NODES - 1)
 +
 
 +
# start master
 +
$SPARK_HOME/sbin/start-master.sh &
 +
 
 +
# start workers
 +
# use spark defaults for worker resources (all mem -1 GB, all cores) since using exclusive
 +
 
 +
$SPARK_HOME/sbin/start-slave.sh spark://$SPARK_MASTER_NODE:$SPARK_MASTER_PORT
 +
</source>
 +
</div>
 +
</div>
 +
<div class="mw-collapsible mw-collapsed" style="width:70%; padding: 5px; border: 1px solid gray;">
 +
''Expand this section to view pi_with_pythonstartup.py''
 +
<div class="mw-collapsible-content" style="padding: 5px;">
 +
<source lang=python>
 +
from operator import add
 +
from random import random
 +
 
 +
partitions =10
 +
n = 100000 * partitions
 +
 
 +
def f(_):
 +
    x = random() * 2 - 1
 +
    y = random() * 2 - 1
 +
    return 1 if x ** 2 + y ** 2 <= 1 else 0
 +
 
 +
count = sc.parallelize(range(1, n + 1), partitions).map(f).reduce(add)
 +
print("Pi is roughly %f" % (4.0 * count / n))
 +
</source>
 +
</div>
 +
</div>
 
|}}
 
|}}
 
<!--Policy-->
 
<!--Policy-->

Latest revision as of 22:01, 15 December 2022

Description

spark website  

Apache Spark is a fast and general-purpose cluster computing system. It provides high-level APIs in Java, Scala, Python and R, and an optimized engine that supports general execution graphs. It also supports a rich set of higher-level tools including Spark SQL for SQL and structured data processing, MLlib for machine learning, GraphX for graph processing, and Spark Streaming.

Environment Modules

Run module spider spark to find out what environment modules are available for this application.

System Variables

  • HPC_SPARK_DIR - installation directory
  • HPC_SPARK_BIN - executable directory
  • HPC_SPARK_SLURM - SLURM job script examples
  • SPARK_HOME - examples directory

Running Spark on HiperGator

To run your Spark jobs on HiperGator, two separate steps are required:

  1. Create a Spark cluster on HiperGator via SLURM. This section "Spark Cluster on HiPerGator" below shows a simple example how to create a Spark cluster on HiperGator.
  2. Submit your job to your Spark cluster. You can do this either interactively at the command line ("Spark Interactive Job" section below) or by submitting a a batch job ("Spark Batch Job" section below)

For details about running Spark jobs on HiPerGator, please refer to Spark Workshop. For Spark parameters used in this section, please refer to Spark's homepage.

Spark cluster on HiperGator

Expand this section to view instructions for creating a spark cluster in HiperGator.

It is assumed that spark-local-cluster.sh is the file name of the SLURM job script for one-worker node Spark cluster in this section. Set SLURM parameters for Spark cluster. spark-local-cluster.sh is available on "Spark_Job_Scripts" page below. 

 #!/bin/bash
 #filename: spark-local-cluster.sh
 #SBATCH --job-name=spark_cluster
 #SBATCH --nodes=1 # nodes allocated to the job
 #SBATCH --cpus-per-task=16 # the number of CPUs allocated per task
 #SBATCH --exclusive # not sharing of allocated nodes with other running jobs
 #SBATCH --time=03:00:00
 #SBATCH --output=spark_cluster.log
 #SBATCH --error=spark_cluster.err

 module load spark

 ## Set Spark parameters for Spark cluster
 export SPARK_LOCAL_DIRS=$HOME/spark/tmp
 export SPARK_WORKER_DIR=$SPARK_LOCAL_DIRS
 export SPARK_WORKER_CORES=$SLURM_CPUS_PER_TASK
 export SPARK_MASTER_PORT=7077
 export SPARK_MASTER_WEBUI_PORT=8080
 export SPARK_NO_DAEMONIZE=true
 export SPARK_LOG_DIR=$SPARK_LOCAL_DIRS

 mkdir -p $SPARK_LOCAL_DIRS

 ##Set Spark Master and Workers
 MASTER_HOST=$(scontrol show hostname $SLURM_NODELIST | head -n 1)
 export SPARK_MASTER_NODE=$(host $MASTER_HOST | head -1 | cut -d ' ' -f 4)
 export MAX_SLAVES=$(expr $SLURM_JOB_NUM_NODES - 1)

 ## for starting spark master
 $SPARK_HOME/sbin/start-master.sh & 

 ## use spark defaults for worker resources (all mem -1 GB, all cores) since using exclusive
 ## for starting spark worker
 $SPARK_HOME/sbin/start-slave.sh spark://$SPARK_MASTER_NODE:$SPARK_MASTER_PORT

Submit the SLURM job script to HiperGator 

sbatch spark-local-cluster.sh

Check the Spark master launched. 

grep "Starting Spark master" spark_cluster.err

This grep command above should end up with information like 

18/03/13 14:53:23 INFO Master: Starting Spark master at spark://c29a-s42.ufhpc:7077

Check the Spark worker launched. 

grep "Starting Spark worker" spark_cluster.err

This grep command above should end up with information like 

18/03/13 14:53:24 INFO Worker: Starting Spark worker 172.16.194.59:42418 with 16 cores, 124.3 GB RAM

Spark interactive job

Expand this section to view instructions for starting preset applications without a job script.

Spark supports interactive job submission through the interactive shells.

Spark interactive shell in Scalar (spark-shell)

First, load spark module in the terminal where you want to submit a spark job. 

module load spark

Get the location of the Spark master to connect to it through the interactive shell 

SPARK_MASTER=$(grep "Starting Spark master" *.err | cut -d " " -f 9)

Connect to the master using the Spark interactive shell in scalar 

spark-shell --master $SPARK_MASTER
Spark interactive shell in Python (pyspark)

Load spark module in the terminal where you want to submit a spark job. 

module load spark

Get the location of the Spark master to connect to it through the interactive shell 

SPARK_MASTER=$(grep "Starting Spark master" *.err | cut -d " " -f 9)

Connect to the master using the Spark interactive shell in scalar 

pyspark --master $SPARK_MASTER
Example - PI estimation via pyspark
SPARK_MASTER=$(grep "Starting Spark master" *.err | cut -d " " -f 9)
pyspark --master $SPARK_MASTER

Pi with pyspark.png

Example - Pi estimation from file with pyspark

As of Spark 2.0., Spark interactive shell in python does not load python files to run python application. Instead, “PYTHONSTARTUP”, a python environmental variable can be used to run python script with pyspark, which executes the python script before an interactive shell starts. 

SPARK_MASTER=$(grep "Starting Spark master" *.err | cut -d " " -f 9)
PYTHONSTARTUP=pi_with_pythonstartup.py pyspark --master $SPARK_MASTER

pi_with_pythonstartup.py script is avaialble on "Spark_Job_Scripts" page below.

Spark batch job

Expand this section to view instructions for starting preset applications without a job script.

Spark supports batch job submission through spark-submit which provides unified interface for Spark jobs 

$SPARK_HOME/bin/spark-submit  \
             --class <main-class>  --master <master-url> \
             --deploy-mode <deploy-mode>  --conf <key>=<value>  \
            ... # other options  <application-jar>  [application-arguments]

--class: The entry point for your application (e.g. org.apache.spark.examples.SparkPi)
--master: The master URL for the cluster (e.g. spark://123.45.67.890:7077)
--deploy-mode: Whether to deploy your driver on the worker nodes (cluster) or locally as an external client (client) (default: client)
--conf: Arbitrary Spark configuration property in key=value format. For values that contain spaces wrap “key=value” in quotes (as shown).
<application-jar>: Path to a bundled jar including your application and all dependencies. The URL must be globally visible inside of your cluster, 
  for instance, an hdfs:// path or a file:// path that is present on all nodes.
<application-arguments>: Arguments passed to the main method of your main class, if any

For further details about spark-submit, refer to https://spark.apache.org/docs/2.2.0/submitting-applications.html.

Example - Pi estimation via Spark-submit
SPARK_MASTER=$(grep "Starting Spark master" *.err | cut -d " " -f 9)
spark-submit --master $SPARK_MASTER $SPARK_HOME/examples/src/main/python/pi.py 10

Pi spark-submit.png


Job Script Examples

Expand this section to view spark-local-cluster.sh 

#!/bin/bash
#filename: spark-local-cluster.sh

#SBATCH --job-name=spark_cluster
#SBATCH --nodes=1 # nodes allocated to the job
#SBATCH --cpus-per-task=16 # the number of CPUs allocated per task
#SBATCH --exclusive # not sharing of allocated nodes with other running jobs
#SBATCH --time=03:00:00
#SBATCH --output=spark_cluster.log
#SBATCH --error=spark_cluster.err

###SBATCH --ntasks= # tasks to be created for the job
###SBATCH --ntasks-per-core= # max number of tasks per allocated core
###SBATCH --ntasks-per-node= # max number of tasks per allocated node
###SBATCH --mail-type=END,FAIL
###SBATCH --mail-user=<yourID>@ufl.edu

module load spark
### Set Spark variables
export SPARK_LOCAL_DIRS=$HOME/spark/tmp
export SPARK_WORKER_DIR=$SPARK_LOCAL_DIRS
export SPARK_WORKER_CORES=$SLURM_CPUS_PER_TASK
export SPARK_MASTER_PORT=7077
export SPARK_MASTER_WEBUI_PORT=8080
export SPARK_NO_DAEMONIZE=true
export SPARK_LOG_DIR=$SPARK_LOCAL_DIRS
#export SPARK_CONF_DIR=$SPARK_LOCAL_DIRS
mkdir -p $SPARK_LOCAL_DIRS

MASTER_HOST=$(scontrol show hostname $SLURM_NODELIST | head -n 1)
export SPARK_MASTER_NODE=$(host $MASTER_HOST | head -1 | cut -d ' ' -f 4)
export MAX_SLAVES=$(expr $SLURM_JOB_NUM_NODES - 1)

# start master
$SPARK_HOME/sbin/start-master.sh &

# start workers
# use spark defaults for worker resources (all mem -1 GB, all cores) since using exclusive

$SPARK_HOME/sbin/start-slave.sh spark://$SPARK_MASTER_NODE:$SPARK_MASTER_PORT

Expand this section to view pi_with_pythonstartup.py 

from operator import add
from random import random

partitions =10
n = 100000 * partitions

def f(_):
    x = random() * 2 - 1
    y = random() * 2 - 1
    return 1 if x ** 2 + y ** 2 <= 1 else 0

count = sc.parallelize(range(1, n + 1), partitions).map(f).reduce(add)
print("Pi is roughly %f" % (4.0 * count / n))




Retrieved from "https://help.rc.ufl.edu/mediawiki/index.php?title=Spark&oldid=27071"