hadoop-yarn-issues mailing list archives

Site index · List index
Message view « Date » · « Thread »
Top « Date » · « Thread »
From "Doug Haigh (JIRA)" <j...@apache.org>
Subject [jira] [Commented] (YARN-2625) Problems with CLASSPATH in Job Submission REST API
Date Mon, 05 Jan 2015 13:14:35 GMT

    [ https://issues.apache.org/jira/browse/YARN-2625?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=14264577#comment-14264577
] 

Doug Haigh commented on YARN-2625:
----------------------------------

I am not using MR. I am writing my own AppMaster which requires knowing the path to the Hadoop
ecosystem's CLASSPATH. Unless you expect Hadoop to be rewritten in something other than JAVA,
most AppMaster jars written in Java will be required to know the CLASSPATH of the Hadoop ecosystem
they are expected to run under. If you want to add a REST API to specifically get the CLASSPATH
of the Hadoop ecosystem a Java AppMaster will run under, that is fine with me.

> Problems with CLASSPATH in Job Submission REST API
> --------------------------------------------------
>
>                 Key: YARN-2625
>                 URL: https://issues.apache.org/jira/browse/YARN-2625
>             Project: Hadoop YARN
>          Issue Type: Bug
>          Components: api
>    Affects Versions: 2.5.1
>            Reporter: Doug Haigh
>
> There are a couple of issues I have found specifying the CLASSPATH environment variable
using the REST API.
> 1) In the Java client, the CLASSPATH environment is usually made up of either the value
of the yarn.application.classpath in yarn-site.xml value or the default YARN classpath value
as defined by YarnConfiguration.DEFAULT_YARN_CROSS_PLATFORM_APPLICATION_CLASSPATH. REST API
consumers have no method of telling the resource manager to use the default unless they hardcode
the default value themselves. If the default ever changes, the code would need to change.

> 2) If any environment variables are used in the CLASSPATH environment 'value' field,
they are evaluated when the values are NULL resulting in bad values in the CLASSPATH. For
example, if I had hardcoded the CLASSPATH value to the default of "$HADOOP_CONF_DIR, $HADOOP_COMMON_HOME/share/hadoop/common/*,
$HADOOP_COMMON_HOME/share/hadoop/common/lib/*, $HADOOP_HDFS_HOME/share/hadoop/hdfs/*, $HADOOP_HDFS_HOME/share/hadoop/hdfs/lib/*,
$HADOOP_YARN_HOME/share/hadoop/yarn/*, $HADOOP_YARN_HOME/share/hadoop/yarn/lib/*" the classpath
passed to the application master is ":/share/hadoop/common/*:/share/hadoop/common/lib/*:/share/hadoop/hdfs/*:/share/hadoop/hdfs/lib/*:/share/hadoop/yarn/*:/share/hadoop/yarn/lib/*"
> These two problems require REST API consumers to always have the fully resolved path
defined in the yarn.application.classpath value. If the property is missing or contains environment
varaibles, the application created by the REST API will fail due to the CLASSPATH being incorrect.



--
This message was sent by Atlassian JIRA
(v6.3.4#6332)

Mime
View raw message