Details
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Improvement
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Status: Open
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Major
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Resolution: Unresolved
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2.4.1
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None
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None
Description
In most cases, we want to use -Dmapreduce.user.classpath.first=true to pick user's jars ahead of hadoop system's jars, which can make tasks run based upon the customized environment under the circumstance that hadoop system default library contains the different version of dependent jars.
However, using -Dmapreduce.user.classpath.first=true will cause ApplicationMaster failure to launch due to conflicting classes.
In most cases, if users do not customize the ApplicationMaster for MapReduce framework, I believe we can treat MRAppMaster different with MapTask/ReduceTask at the point of loading user's jar in classloader.
I believe it can provide a property of '-Dmapreduce.am.user.classpath.first=false' to disable the feature of loading user's jars firstly.