First Version

.gitignore

+slurm-*.out
+spark-cluster-*

README.md

 # Spark-Examples
 
+## Interactive Spark Cluster
+Script `start_spark_cluster.sh`.
 
+Spawns a Spark Master and Spark Workers and waits until Job Timeout. Weird parametrization (e.g. 7 workers threads) to see that it actually works. Unclear:
+- In the Scala Example, is uses 7 worker instances as expected. The Python Example uses only 2. Why?
+- How to run workers on more than one node? Probably with `srun`
+- Executing `srun -n 1 start-worker.sh $MASTER_URL` leads to a quiet failure (?) of the workers. Why?
 
-## Getting started
-
-To make it easy for you to get started with GitLab, here's a list of recommended next steps.
-
-Already a pro? Just edit this README.md and make it your own. Want to make it easy? [Use the template at the bottom](#editing-this-readme)!
-
-## Add your files
-
-- [ ] [Create](https://docs.gitlab.com/ee/user/project/repository/web_editor.html#create-a-file) or [upload](https://docs.gitlab.com/ee/user/project/repository/web_editor.html#upload-a-file) files
-- [ ] [Add files using the command line](https://docs.gitlab.com/ee/gitlab-basics/add-file.html#add-a-file-using-the-command-line) or push an existing Git repository with the following command:
-
-```
-cd existing_repo
-git remote add origin https://gitlab.jsc.fz-juelich.de/AI_Recipe_Book/recipes/spark-examples.git
-git branch -M main
-git push -uf origin main
-```
-
-## Integrate with your tools
-
-- [ ] [Set up project integrations](https://gitlab.jsc.fz-juelich.de/AI_Recipe_Book/recipes/spark-examples/-/settings/integrations)
-
-## Collaborate with your team
-
-- [ ] [Invite team members and collaborators](https://docs.gitlab.com/ee/user/project/members/)
-- [ ] [Create a new merge request](https://docs.gitlab.com/ee/user/project/merge_requests/creating_merge_requests.html)
-- [ ] [Automatically close issues from merge requests](https://docs.gitlab.com/ee/user/project/issues/managing_issues.html#closing-issues-automatically)
-- [ ] [Enable merge request approvals](https://docs.gitlab.com/ee/user/project/merge_requests/approvals/)
-- [ ] [Automatically merge when pipeline succeeds](https://docs.gitlab.com/ee/user/project/merge_requests/merge_when_pipeline_succeeds.html)
-
-## Test and Deploy
-
-Use the built-in continuous integration in GitLab.
-
-- [ ] [Get started with GitLab CI/CD](https://docs.gitlab.com/ee/ci/quick_start/index.html)
-- [ ] [Analyze your code for known vulnerabilities with Static Application Security Testing(SAST)](https://docs.gitlab.com/ee/user/application_security/sast/)
-- [ ] [Deploy to Kubernetes, Amazon EC2, or Amazon ECS using Auto Deploy](https://docs.gitlab.com/ee/topics/autodevops/requirements.html)
-- [ ] [Use pull-based deployments for improved Kubernetes management](https://docs.gitlab.com/ee/user/clusters/agent/)
-- [ ] [Set up protected environments](https://docs.gitlab.com/ee/ci/environments/protected_environments.html)
-
-***
-
-# Editing this README
-
-When you're ready to make this README your own, just edit this file and use the handy template below (or feel free to structure it however you want - this is just a starting point!). Thank you to [makeareadme.com](https://www.makeareadme.com/) for this template.
-
-## Suggestions for a good README
-Every project is different, so consider which of these sections apply to yours. The sections used in the template are suggestions for most open source projects. Also keep in mind that while a README can be too long and detailed, too long is better than too short. If you think your README is too long, consider utilizing another form of documentation rather than cutting out information.
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-## Name
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-## Installation
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-## Usage
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-## Contributing
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-## Authors and acknowledgment
-Show your appreciation to those who have contributed to the project.
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-## Project status
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+## References
+- Pi Estimate (Python + Scala): [](https://spark.apache.org/examples.html)
+- Simple Slurm Example (not completely compatible): [](https://info.gwdg.de/wiki/doku.php?id=wiki:hpc:slurm_sbatch_script_for_spark_applications)

pyspark_pi.py

+import pyspark
+import random
+import os
+
+sc = pyspark.SparkContext(os.environ["MASTER_URL"])
+
+def inside(p):
+    x, y = random.random(), random.random()
+    return x*x + y*y < 1
+
+NUM_SAMPLES=10000000
+count = sc.parallelize(range(0, NUM_SAMPLES)) \
+             .filter(inside).count()
+print("Pi is roughly %f" % (4.0 * count / NUM_SAMPLES))

start_spark_cluster.sh

+#!/bin/bash
+
+#SBATCH --partition=develbooster
+#SBATCH --account=atmlaml
+#SBATCH --nodes=1
+#SBATCH --tasks-per-node=9
+#SBATCH --time=00:60:00
+#SBATCH --gres gpu
+#SBATCH --job-name spark-cluster
+ 
+module load Stages/2023  GCC  OpenMPI Spark
+
+JOB="$SLURM_JOB_NAME-$SLURM_JOB_ID"
+export SPARK_WORKER_DIR="$SLURM_SUBMIT_DIR/$JOB/worker"
+export SPARK_LOG_DIR="$SLURM_SUBMIT_DIR/$JOB/log"
+export SPARK_MASTER_HOST=`hostname`
+export SPARK_MASTER_PORT="4124"
+export SPARK_WORKER_CORES=7
+export SPARK_WORKER_INSTANCES=5 ## This is not working yet
+export MASTER_URL="spark://${SPARK_MASTER_HOST}:${SPARK_MASTER_PORT}"
+export > ${SPARK_LOG_DIR}/env.txt
+
+echo "------------ Starting Spark Server -------------"
+echo "MASTER_URL: $MASTER_URL"
+echo "------------------------------------------------"
+start-master.sh
+
+echo "------------ Starting Spark Workers ------------"
+echo "MASTER_URL: $MASTER_URL"
+echo "------------------------------------------------"
+
+#srun -n 14 spark-class org.apache.spark.deploy.worker.Worker $MASTER_URL
+#srun -n 1 start-worker.sh $MASTER_URL
+start-worker.sh $MASTER_URL
+
+. wait-worker.sh
+
+echo "----------- How to test with spark shell ------"
+echo "sgoto $SLURM_JOB_ID 0"
+echo "module load Stages/2023  GCC  OpenMPI Spark"
+echo "export MASTER_URL=$MASTER_URL"
+echo "spark-shell --master \$MASTER_URL"
+echo "# Now your shell should connect to the spark master"
+echo
+echo "In the shell you can now execute the following test script"
+echo
+echo ">>>>"
+echo "val NUM_SAMPLES=1000000"
+echo "val count = sc.parallelize(1 to NUM_SAMPLES).filter { _ =>"
+echo "  val x = math.random"
+echo "  val y = math.random"
+echo "  x*x + y*y < 1"
+echo "}.count()"
+echo "println(s\"Pi is roughly \${4.0 * count / NUM_SAMPLES}\")"
+echo "<<<<"
+echo "------------------------------------------------"
+echo
+echo "----------- How to test with pyspark ------"
+echo "sgoto $SLURM_JOB_ID 0"
+echo "module load Stages/2023  GCC  OpenMPI Spark"
+echo "export MASTER_URL=$MASTER_URL"
+echo "python pyspark_pi.py"
+echo "------------------------------------------------"
+echo 
+echo "---------- How to kill -------------------------"
+echo scancel $SLURM_JOB_ID
+echo "------------------------------------------------"
+
+
+sleep infinity
+ 
+

wait-worker.sh

+. $SPARK_CONF_DIR/spark-env.sh
+num_workers=1 #`cat $SPARK_CONF_DIR/slaves|wc -l`
+echo number of workers to be registered: $num_workers
+master_logfile=`ls -tr ${SPARK_LOG_DIR}/*master* |tail -1`
+worker_logfiles=`ls -tr ${SPARK_LOG_DIR}/*worker* |tail -$num_workers`
+steptime=3
+for i in {1..100}
+do
+  sleep $steptime
+  num_reg=` grep 'registered' $worker_logfiles|wc -l`
+  if [ $num_reg -eq $num_workers ]
+  then
+     break
+  fi
+done
+echo registered workers after $((i * steptime)) seconds  :
+for file in $worker_logfiles
+do
+  grep 'registered' $file
+done
+grep 'Starting Spark master' $master_logfile
+grep 'Registering worker' $master_logfile|tail -$num_workers