Hadoop-related options

Since mrjob is geared toward Hadoop, there are a few Hadoop-specific options. However, due to the difference between the different runners, the Hadoop platform, and Elastic MapReduce, they are not all available for all runners.

Options specific to the local and inline runners

hadoop_version (--hadoop-version) : string

Default: None

Set the version of Hadoop to simulate (this currently only matters for jobconf).

If you don’t set this, the local and inline runners will run in a version-agnostic mode, where anytime the runner sets a simulated jobconf variable, it’ll use every possible name for it (e.g. user.name and mapreduce.job.user.name).

num_cores (--num-cores) : integer

Default: None

Maximum number of tasks to handle at one time. If not set, defaults to the number of CPUs on your system.

This also affects the number of input file splits the runner makes (the only impact in inline mode).

New in version 0.6.2.

Options available to local, hadoop, and emr runners

These options are both used by Hadoop and simulated by the local and inline runners to some degree.

jobconf (-D, --jobconf) : dict

Default: {}

-D args to pass to hadoop streaming. This should be a map from property name to value. Equivalent to passing ['-D', 'KEY1=VALUE1', '-D', 'KEY2=VALUE2', ...] to hadoop_extra_args

Changed in version 0.6.6: added the -D switch on the command line, to match Hadoop.

Options available to hadoop and emr runners

hadoop_extra_args (--hadoop-arg) : string list

Default: []

Extra arguments to pass to hadoop streaming.

hadoop_streaming_jar (--hadoop-streaming-jar) : string

Default: (automatic)

Path to a custom hadoop streaming jar.

On EMR, this can be either a local path or a URI (s3://...). If you want to use a jar at a path on the master node, use a file:// URI.

On Hadoop, mrjob tries its best to find your hadoop streaming jar, searching these directories (recursively) for a .jar file with hadoop followed by streaming in its name:

• $HADOOP_PREFIX
• $HADOOP_HOME
• $HADOOP_INSTALL
• $HADOOP_MAPRED_HOME
• the parent of the directory containing the Hadoop binary (see hadoop_bin), unless it’s one of /, /usr or /usr/local
• $HADOOP_*_HOME (in alphabetical order by environment variable name)
• /home/hadoop/contrib
• /usr/lib/hadoop-mapreduce

(The last two paths allow the Hadoop runner to work out-of-the box inside EMR.)

libjars (--libjar) : string list

Default: []

List of paths of JARs to be passed to Hadoop with the -libjar switch.

~ and environment variables within paths will be resolved based on the local environment.

New in version 0.5.3.

Note

mrjob does not yet support libjars on Google Cloud Dataproc.

label (--label) : string

Default: script’s module name, or no_script

Alternate label for the job

owner (--owner) : string

Default: getpass.getuser(), or no_user if that fails

Who is running this job (if different from the current user)

check_input_paths (--check-input-paths, --no-check-input-paths) : boolean

Default: True

Option to skip the input path check. With --no-check-input-paths, input paths to the runner will be passed straight through, without checking if they exist.

spark_args (--spark-arg) : string list

Default: []

Extra arguments to pass to spark-submit.

New in version 0.5.7.

Options available to hadoop runner only

hadoop_bin (--hadoop-bin) : command

Default: (automatic)

Name/path of your hadoop binary (may include arguments).

mrjob tries its best to find hadoop, checking all of the following places for an executable file named hadoop:

• $HADOOP_PREFIX/bin
• $HADOOP_HOME/bin
• $HADOOP_INSTALL/bin
• $HADOOP_INSTALL/hadoop/bin
• $PATH
• $HADOOP_*_HOME/bin (in alphabetical order by environment variable name)

If all else fails, we just use hadoop and hope for the best.

hadoop_log_dirs (--hadoop-log-dir) : path list

Default: (automatic)

Where to look for Hadoop logs (to find counters and probable cause of job failure). These can be (local) paths or URIs (hdfs:///...).

If this is not set, mrjob will try its best to find the logs, searching in:

• $HADOOP_LOG_DIR
• $YARN_LOG_DIR (on YARN only)
• hdfs:///tmp/hadoop-yarn/staging (on YARN only)
• <job output dir>/_logs (usually this is on HDFS)
• $HADOOP_PREFIX/logs
• $HADOOP_HOME/logs
• $HADOOP_INSTALL/logs
• $HADOOP_MAPRED_HOME/logs
• <dir containing hadoop bin>/logs (see hadoop_bin), unless the hadoop binary is in /bin, /usr/bin, or /usr/local/bin
• $HADOOP_*_HOME/logs (in alphabetical order by environment variable name)
• /var/log/hadoop-yarn (on YARN only)
• /mnt/var/log/hadoop-yarn (on YARN only)
• /var/log/hadoop
• /mnt/var/log/hadoop

New in version 0.5.0.

Changed in version 0.5.3: Added paths in /var/log and /mnt/var/log/hadoop-yarn

hadoop_tmp_dir (--hadoop-tmp-dir) : path

Default: tmp/mrjob

Scratch space on HDFS. This path does not need to be fully qualified with hdfs:// URIs because it’s understood that it has to be on HDFS.

Changed in version 0.5.0: This option used to be named hdfs_scratch_dir.

spark_master (--spark-master) : string

Default: 'yarn'

Name or URL to pass to the --master argument of spark-submit (e.g. spark://host:port, yarn).

Note that archives (see upload_archives) only work when this is set to yarn.

spark_submit_bin (--spark-submit-bin) : command

Default: (automatic)

Name/path of your spark-submit binary (may include arguments).

mrjob tries its best to find spark-submit, checking all of the following places for an executable file named spark-submit:

• $SPARK_HOME/bin
• $PATH
• /usr/lib/spark/bin
• /usr/local/spark/bin
• /usr/local/lib/spark/bin

If all else fails, we just use spark-submit and hope for the best.

New in version 0.5.7.