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MapReduce Job — POST mapreduce/jar

Description

Creates and queues a standard Hadoop MapReduce job.

Version: Hive 0.13.0 and later

As of Hive 0.13.0, GET version/hadoop displays the Hadoop version used for the MapReduce job.

URL

http://www.myserver.com/templeton/v1/mapreduce/jar

Parameters

Name

Description

Required?

Default

jar

Name of the jar file for Map Reduce to use.

Required

None

class

Name of the class for Map Reduce to use.

Required

None

libjars

Comma separated jar files to include in the classpath.

Optional

None

files

Comma separated files to be copied to the map reduce cluster.

Optional

None

arg

Set a program argument.

Optional

None

define

Set a Hadoop configuration variable using the syntax define=NAME=VALUE

Optional

None

statusdir

A directory where WebHCat will write the status of the Map Reduce job. If provided, it is the caller's responsibility to remove this directory when done.

Optional

None

enablelog

If statusdir is set and enablelog is "true", collect Hadoop job configuration and logs into a directory named $statusdir/logs after the job finishes. Both completed and failed attempts are logged. The layout of subdirectories in $statusdir/logs is: 

logs/$job_id (directory for $job_id) 
logs/$job_id/job.xml.html 
logs/$job_id/$attempt_id (directory for $attempt_id) 
logs/$job_id/$attempt_id/stderr 
logs/$job_id/$attempt_id/stdout 
logs/$job_id/$attempt_id/syslog 

This parameter was introduced in Hive 0.12.0. (See HIVE-4531.)

Optional in Hive 0.12.0+None

callback

Define a URL to be called upon job completion. You may embed a specific job ID into this URL using $jobId. This tag will be replaced in the callback URL with this job's job ID.

Optional

None

usehcatalog

Specify that the submitted job uses HCatalog and therefore needs to access the metastore, which requires additional steps for WebHCat to perform in a secure cluster. (See HIVE-5133.) This parameter will be introduced in Hive 0.13.0.
Also, if webhcat-site.xml defines the parameters templeton.hive.archive, templeton.hive.home and templeton.hcat.home then WebHCat will ship the Hive tar to the target node where the job runs. (See HIVE-5547.) This means that Hive doesn't need to be installed on every node in the Hadoop cluster. This is independent of security, but improves manageability.
The webhcat-site.xml parameters are documented in webhcat-default.xml.

Optional in Hive 0.13.0+

false

The standard parameters are also supported.

Results

Name

Description

id

A string containing the job ID similar to "job_201110132141_0001".

info

A JSON object containing the information returned when the job was queued. See the Hadoop documentation (Class TaskController) for more information.

Example

Code and Data Setup

% hadoop fs -put wordcount.jar .
% hadoop fs -put transform.jar .

% hadoop fs -ls .
Found 2 items
-rw-r--r--   1 ctdean supergroup         23 2011-11-11 13:29 /user/ctdean/wordcount.jar
-rw-r--r--   1 ctdean supergroup         28 2011-11-11 13:29 /user/ctdean/transform.jar

Curl Command

% curl -s -d jar=wordcount.jar \
       -d class=org.myorg.WordCount \
       -d libjars=transform.jar \
       -d arg=wordcount/input \
       -d arg=wordcount/output \
       'http://localhost:50111/templeton/v1/mapreduce/jar?user.name=ekoifman'

Version information

Prior to Hive 0.13.0, user.name was specified in POST requests as a form parameter: curl -d user.name=<user>.

In Hive 0.13.0 onward, user.name should be specified in the query string (as shown above): 'http://.../templeton/v1/mapreduce/jar?user.name=<name>'. Specifying user.name as a form parameter is deprecated.

JSON Output

{
 "id": "job_201111121211_0001",
 "info": {
          "stdout": "templeton-job-id:job_201111121211_0001
                    ",
          "stderr": "",
          "exitcode": 0
         }
}
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