I have created a Spark EMR cluster. I would like to execute jobs either on my localhost or EMR cluster.
Assuming I run spark-shell on my local computer how can I tell it to connect to the Spark EMR cluster, what would be the exact configuration options and/or commands to run.
It looks like others have also failed at this and ended up running the Spark driver on EMR, but then making use of e.g. Zeppelin or Jupyter running on EMR.
Setting up our own machines as spark drivers that connected to the core nodes on EMR would have been ideal. Unfortunately, this was impossible to do and we forfeited after trying many configuration changes. The driver would start up and then keep waiting unsuccessfully, trying to connect to the slaves.
Most of our Spark development is on pyspark using Jupyter Notebook as our IDE. Since we had to run Jupyter from the master node, we couldn’t risk losing our work if the cluster were to go down. So, we created an EBS volume and attached it to the master node and placed all of our work on this volume. [...]
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Note: If you go down this route, I would consider using S3 for storing notebooks, then you don't have to manage EBS volumes.
One way of doing this is to add your spark job as an EMR step to your EMR cluster. For this, you need AWS CLI installed on your local computer
(see here for installation guide), and your jar file on s3.
Once you have aws cli, assuming your spark class to run is com.company.my.MySparkJob and your jar file is located on s3 at s3://hadi/my-project-0.1.jar, you can run the following command from your terminal:
aws emr add-steps --cluster-id j-************* --steps Type=spark,Name=My_Spark_Job,Args=[-class,com.company.my.MySparkJob,s3://hadi/my-project-0.1.jar],ActionOnFailure=CONTINUE
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I know there is information worth 10 google pages on this but, all of them tell me to just put --master yarn in the spark-submit command. But, in cluster mode, how can my local laptop even know what that means? Let us say I have my laptop and a running dataproc cluster. How can I use spark-submit from my laptop to submit a job to this cluster?
Most of the documentation on running a Spark application in cluster mode assumes that you are already on the same cluster where YARN/Hadoop are configured (e.g. you are ssh'ed in), in which case most of the time Spark will pick up the appropriate local configs and "just work".
This is same for Dataproc: if you ssh onto the Dataproc master node, you can just run spark-submit --master yarn. More detailed instructions can be found in the documentation.
If you are trying to run applications locally on your laptop, this is more difficult. You will need to set up an ssh tunnel to the cluster, and then locally create configuration files that tell Spark how to reach the master via the tunnel.
Alternatively, you can use the Dataproc jobs API to submit jobs to the cluster without having to directly connect. The one caveat is that you will have to use properties to tell Spark to run in cluster mode instead of client mode (--properties spark.submit.deployMode=cluster). Note that when submitting jobs via the Dataproc API, the difference between client and cluster mode is much less pressing because in either case the Spark driver will actually run on the cluster (on the master or a worker respectively), not on your local laptop.
What is the difference between submitting a EMR step as below vs running a spark submit on master node of the EMR cluster.
EMR step
aws emr add-steps --cluster-id j-2AXXXXXXGAPLF --steps Type=Spark,Name="Spark Program",ActionOnFailure=CONTINUE,Args=[--class,org.apache.spark.examples.SparkPi,/usr/lib/spark/lib/spark-examples.jar,10]
Spark Submit
spark-submit --master yarn --deploy-mode cluster my_spark_app.py my_hdfs_file.csv
Will running the spark submit directly on master node make it distributed between core nodes.
What is the change in performance between these two methods?Which is a better approach
Submitting via EMR Step gives some additional monitoring and tooling on the AWS platform.
EMR has CloudWatch metrics for running/completed/failed steps.
EMR steps dispatch Eventbridge events on complete/failure which can be used as triggers.
If your EMR cluster is running on a private subnet, you'll have to tunnel to the subnet to monitor your jobs, EMR step status does not have this limitation.
Similar to above, if your cluster is on a private subnet, you'll have to tunnel in via ssh to call spark-submit, EMR API is publicly addressable.
EMR RunJobFlowStep has AWS Step Functions integration if you want to run an EMR job as part of a workflow via state machine.
I'm sure there are others but these are the benefits I've seen.
Edit:
One caveat - with EMR steps you'll need to submit the job via command-runner.jar and these end up as running processes on your master node for the life of the EMR step. If you're running hundreds of steps, you may end up needing a larger master node to support all of these processes.
I'm trying to figure out which is the best way to work with Airflow and Spark/Hadoop.
I already have a Spark/Hadoop cluster and I'm thinking about creating another cluster for Airflow that will submit jobs remotely to Spark/Hadoop cluster.
Any advice about it? Looks like it's a little complicated to deploy spark remotely from another cluster and that will create some file configuration duplication.
You really only need to configure a yarn-site.xml file, I believe, in order for spark-submit --master yarn --deploy-mode client to work. (You could try cluster deploy mode, but I think having the driver being managed by Airflow isn't a bad idea)
Once an Application Master is deployed within YARN, then Spark is running locally to the Hadoop cluster.
If you really want, you could add a hdfs-site.xml and hive-site.xml to be submitted as well from Airflow (if that's possible), but otherwise at least hdfs-site.xml files should be picked up from the YARN container classpath (not all NodeManagers could have a Hive client installed on them)
I prefer submitting Spark Jobs using SSHOperator and running spark-submit command which would save you from copy/pasting yarn-site.xml. Also, I would not create a cluster for Airflow if the only task that I perform is running Spark jobs, a single VM with LocalExecutor should be fine.
There are a variety of options for remotely performing spark-submit via Airflow.
Emr-Step
Apache-Livy (see this for hint)
SSH
Do note that none of these are plug-and-play ready and you'll have to write your own operators to get things done.
I need to setup spark cluster (1 Master and 2 slaves nodes) on centos7 along with resource manager as YARN. I am new to all this and still exploring. Can somebody share me detailed steps of setting up Spark with Yarn in cluster mode.
Afterwards i have to integrate Livy too(an open source REST interface for using Spark from anywhere).
Inputs are welcome.Thanks
YARN is part of Hadoop. So, a Hadoop installation is necessary to run Spark on YARN.
Check out the page on the Hadoop Cluster Setup.
Then you can utilize the this documentation to learn about Spark on YARN.
Another method to quickly learn about Hadoop, YARN and Spark is to utilize Cloudera Distribution of Hadoop (CDH). Read the CDH 5 Quick Start Guide.
We are currently using the similar setup in aws. AWS EMR is costly hence
we setup our own cluster using ec2 machines with the help of Hadoop Cookbook. The cookbook supports multiple distributions, however we choose HDP.
The setup included following.
Master Setup
Spark (Along with History server)
Yarn Resource Manager
HDFS Name Node
Livy server
Slave Setup
Yarn Node Manager
HDFS Data Node
More information on manually installing can be found in HDP Documentation
You can see the part of that automation in here.
Currently, I can access the HDFS from inside my application, but I'd also like to - instead of running my local spark - to use Cloudera's spark as it is enabled in Cloudera Manager.
Righ now I have the HDFS defined at core-site.xml, and I run my app as (--master) YARN. Thus I don't need to set the machine address to my HDFS files. In this way, my SPARK job runs locally and not in the "cluster." I don't want that for now. When I try to set --master to [namenode]:[port] it does not connect. I wonder if I'm directing to the correct port, or if I have to map this port at docker container. Or if I'm missing something about Yarn setup.
Additionally, I've been testing SnappyData (Inc) solution as a Spark SQL in-memory database. So my goal is to run snappy JVMs locally, but redirecting spark jobs to the VM cluster. The whole idea here is to test some performance against some Hadoop implementation. This solution is not a final product (if snappy is local, and spark is "really" remote, I believe it won't be efficient - but in this scenario, I would bring snappy JVMs to the same cluster..)
Thanks in advance!