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https://issues.apache.org/jira/browse/HADOOP-7939?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=13184540#comment-13184540
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Peter Linnell commented on HADOOP-7939:
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This first patch looks good and putting on my packager's hat on it a good first
step to add some sanity.
While I am new to Apache and Hadoop, FWIW, I've been building rpms for years
and I have maintain(ed) a number of packages and repos for openSUSE and Fedora.
My temptation is to give this a strong +1, with a couple of comments:
Can you extend the comment in line 513 to add. 'Once disabled, you might need
to reboot your machine' This is surely the case with SLES/openSUSE.
I do not understand why libexec is getting moved or even used. I realize it's
not your fault, but I am not a fan of doing that 1. It is not consistent across
distros. 2. There is a move afoot to move all binaries to /usr see:
https://fedoraproject.org/wiki/Features/UsrMove openSUSE 12.2 is currently
planned to do this as well.
As for https://issues.apache.org/jira/browse/HADOOP-6255, well its sub-optimal.
That surely would never pass the smell test to get into a major linux distro as
is. I might get ambitious and provide a patch - if it would be accepted. I do
not see "integration" in the base OS, as so many standard macros and locations
are overridden by un-needed defines.
I do not see HADOOP-4868 as relevant and in fact think this is a more elegant
solution sourcing environment variables in one place.
Roman thanks for this.
> Improve Hadoop subcomponent integration in Hadoop 0.23
> ------------------------------------------------------
>
> Key: HADOOP-7939
> URL: https://issues.apache.org/jira/browse/HADOOP-7939
> Project: Hadoop Common
> Issue Type: Improvement
> Components: build, conf, documentation, scripts
> Affects Versions: 0.23.0
> Reporter: Roman Shaposhnik
> Assignee: Roman Shaposhnik
> Fix For: 0.23.1
>
> Attachments: HADOOP-7939.patch.txt, hadoop-layout.sh
>
>
> h1. Introduction
> For the rest of this proposal it is assumed that the current set
> of Hadoop subcomponents is:
> * hadoop-common
> * hadoop-hdfs
> * hadoop-yarn
> * hadoop-mapreduce
> It must be noted that this is an open ended list, though. For example,
> implementations of additional frameworks on top of yarn (e.g. MPI) would
> also be considered a subcomponent.
> h1. Problem statement
> Currently there's an unfortunate coupling and hard-coding present at the
> level of launcher scripts, configuration scripts and Java implementation
> code that prevents us from treating all subcomponents of Hadoop independently
> of each other. In a lot of places it is assumed that bits and pieces
> from individual subcomponents *must* be located at predefined places
> and they can not be dynamically registered/discovered during the runtime.
> This prevents a truly flexible deployment of Hadoop 0.23.
> h1. Proposal
> NOTE: this is NOT a proposal for redefining the layout from HADOOP-6255.
> The goal here is to keep as much of that layout in place as possible,
> while permitting different deployment layouts.
> The aim of this proposal is to introduce the needed level of indirection and
> flexibility in order to accommodate the current assumed layout of Hadoop
> tarball
> deployments and all the other styles of deployments as well. To this end the
> following set of environment variables needs to be uniformly used in all of
> the subcomponent's launcher scripts, configuration scripts and Java code
> (<SC> stands for a literal name of a subcomponent). These variables are
> expected to be defined by <SC>-env.sh scripts and sourcing those files is
> expected to have the desired effect of setting the environment up correctly.
> # HADOOP_<SC>_HOME
> ## root of the subtree in a filesystem where a subcomponent is expected to
> be installed
> ## default value: $0/..
> # HADOOP_<SC>_JARS
> ## a subdirectory with all of the jar files comprising subcomponent's
> implementation
> ## default value: $(HADOOP_<SC>_HOME)/share/hadoop/$(<SC>)
> # HADOOP_<SC>_EXT_JARS
> ## a subdirectory with all of the jar files needed for extended
> functionality of the subcomponent (nonessential for correct work of the basic
> functionality)
> ## default value: $(HADOOP_<SC>_HOME)/share/hadoop/$(<SC>)/ext
> # HADOOP_<SC>_NATIVE_LIBS
> ## a subdirectory with all the native libraries that component requires
> ## default value: $(HADOOP_<SC>_HOME)/share/hadoop/$(<SC>)/native
> # HADOOP_<SC>_BIN
> ## a subdirectory with all of the launcher scripts specific to the client
> side of the component
> ## default value: $(HADOOP_<SC>_HOME)/bin
> # HADOOP_<SC>_SBIN
> ## a subdirectory with all of the launcher scripts specific to the
> server/system side of the component
> ## default value: $(HADOOP_<SC>_HOME)/sbin
> # HADOOP_<SC>_LIBEXEC
> ## a subdirectory with all of the launcher scripts that are internal to
> the implementation and should *not* be invoked directly
> ## default value: $(HADOOP_<SC>_HOME)/libexec
> # HADOOP_<SC>_CONF
> ## a subdirectory containing configuration files for a subcomponent
> ## default value: $(HADOOP_<SC>_HOME)/conf
> # HADOOP_<SC>_DATA
> ## a subtree in the local filesystem for storing component's persistent
> state
> ## default value: $(HADOOP_<SC>_HOME)/data
> # HADOOP_<SC>_LOG
> ## a subdirectory for subcomponents's log files to be stored
> ## default value: $(HADOOP_<SC>_HOME)/log
> # HADOOP_<SC>_RUN
> ## a subdirectory with runtime system specific information
> ## default value: $(HADOOP_<SC>_HOME)/run
> # HADOOP_<SC>_TMP
> ## a subdirectory with temprorary files
> ## default value: $(HADOOP_<SC>_HOME)/tmp
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