Stratosphere » Stratosphere On YARN

Stratosphere on YARN

Apache Hadoop YARN is a cluster resource management framework. It allows to run various distributed applications on top of a cluster. Stratosphere runs on YARN next to other applications. So users do not have to setup or install anything if there is already a YARN setup.

Requirements

Apache Hadoop 2.2
HDFS

Start Stratosphere Session

Follow these instructions to learn how to lauch a Stratosphere Session within your YARN cluster. A session will start all required Stratosphere services (JobManager and TaskManagers) so that you can submit jobs to the cluster. Note that you can submit multiple jobs per session.

Get Stratosphere Uber-Jar

You only need one file to run Stratosphere on YARN, the Stratosphere Uber-Jar. Download the Uber-jar on the download page.

If you want to build the uber-jar from sources, follow the build instructions. Make sure to use the -Dhadoop.profile=2 profile. You can find the Jar file in stratosphere-dist/target/stratosphere-dist-0.4-SNAPSHOT-yarn-uberjar.jar (Note: The version might be different for you ).

Deploy

Invoke the Jar file using the following command:

java -jar stratosphere-dist-0.4-SNAPSHOT-yarn-uberjar.jar

This command will show you the following overview:

java -jar stratosphere-dist-0.4-SNAPSHOT-yarn-uberjar.jar 
Usage:
   Required
     -n,--container <arg>   Number of Yarn container to allocate (=Number of TaskTrackers)
   Optional
     -c,--conf <arg>                 Path to Stratosphere configuration file
     -g,--generateConf               Place default configuration file in current directory
     -j,--jar <arg>                  Path to Stratosphere jar file
     -jm,--jobManagerMemory <arg>    Memory for JobManager Container [in MB]
     -q,--query                      Display avilable YARN resources (memory, cores)
     -qu,--queue <arg>               Specify YARN queue.
     -tm,--taskManagerMemory <arg>   Memory per TaskManager Container [in MB]
     -tmc,--taskManagerCores <arg>   Virtual CPU cores per TaskManager
     -v,--verbose                    Verbose debug mode

Please note that the Client requires the HADOOP_HOME (or YARN_CONF_DIR or HADOOP_CONF_DIR) environment variable to be set to read the YARN and HDFS configuration.

Example: Issue the following command to allocate 10 TaskTrackers, with 8GB of memory each:

java -jar stratosphere-dist-0.4-SNAPSHOT-yarn-uberjar.jar -n 10 -tm 8192

The jar will automatically create a stratosphere-config.yml in the local directory and use this, if no config file has been specified. Please follow our configuration guide if you want to change something. Stratosphere on YARN will overwrite the following configuration parameters jobmanager.rpc.address (because the JobManager is always allocated at different machines) and taskmanager.tmp.dirs (we are using the tmp directories given by YARN).

The example invocation starts 11 containers, since there is one additional container for the ApplicationMaster and JobTracker.

Once Stratosphere is deployed in your YARN cluster, it will show you the connection details of the JobTracker.

The client has to remain open to keep the deployment intact. We suggest to use screen. It will start another shell that is detachable. So open screen, start Stratosphere on YARN, use CTRL+a then press d to detach the screen session. Use screen -r to resume again.

Submit Job to Stratosphere

Use the following command to submit a Stratosphere Job-jar to the YARN cluster:

java -cp stratosphere-dist-0.4-SNAPSHOT-yarn-uberjar.jar eu.stratosphere.pact.client.CliFrontend

If you have Stratosphere installed from a custom build or a zip file, use the pact-client:

./bin/pact-client.sh

Both commands will show you a help like this:

[...]
Action "run" compiles and submits a PACT program.
  "run" action arguments:
     -a,--arguments <programArgs>   Pact program arguments
     -c,--class <classname>         Pact program assembler class
     -j,--jarfile <jarfile>         Pact program JAR file
     -m,--jobmanager <arg>          Hostname:port of JobManager [optional]
     -w,--wait                      Wait until program finishes
[...]

Use the run action to submit a job to YARN. The uberjar will show you the address of the JobManager in the console.

Example

# Optionally download some sample data first
wget -O hamlet.txt http://www.gutenberg.org/cache/epub/1787/pg1787.txt
# Submit Job to Stratosphere
./bin/pact-client.sh run -m localhost:6123 -j examples/pact/pact-examples-0.4-SNAPSHOT-WordCount.jar --arguments 1 file://`pwd`/hamlet.txt file://`pwd`/wordcount-result.txt

You can use also script without the -m (or --jobmanager) argument, but you have to configure the stratosphere-conf.yaml with the correct JobManager details.

Build Stratosphere for a specific Hadoop version.

This section covers building Stratosphere for a specifiy Hadoop version. Most users do not need to do this manually. The problem is that Stratosphere uses HDFS and YARN which are both from Apache Hadoop. There exist many different builds of Hadoop (from both the upstream project and the different Hadoop distributions.) Typically errors arise with the RPC services. An error could look like this:

ERROR: The job was not successfully submitted to the nephele job manager: eu.stratosphere.nephele.executiongraph.GraphConversionException: Cannot compute input splits for TSV: java.io.IOException: Failed on local exception: com.google.protobuf.InvalidProtocolBufferException: Protocol message contained an invalid tag (zero).; Host Details :