[ http://issues.apache.org/jira/browse/HADOOP-435?page=comments#action_12427636 ] Benjamin Reed commented on HADOOP-435: --------------------------------------
I'm not suggesting that we use my scripts to replace the hadoop scripts, I'm just showing how things can be simplified in some cases. One of the daunting things to me (yes I'm simple minded) was getting hadoop setup and running on my little cluster. With the encapsulated jar file you can actually just copy the file into a shared directory and start everything up to at least try it. (It's also very nice to quickly test things.) If you use the encapsulated jar file, the only thing you need to rsync is a single jar: hadoop.jar, so you simplify things. The point of the scripts is to show that in some cases you may not need the web of scripts to manage hadoop. Especially for those just playing with hadoop or using some other process management system such as Condor. The encapsulated jar file allows for a convenient way to deploy a cluster: you plunk down the jar file and run it. In the current distribution the only thing that would change would be the hadoop script, which would basically become a single line. > Encapsulating startup scripts and jars in a single Jar file. > ------------------------------------------------------------ > > Key: HADOOP-435 > URL: http://issues.apache.org/jira/browse/HADOOP-435 > Project: Hadoop > Issue Type: New Feature > Affects Versions: 0.5.0 > Reporter: Benjamin Reed > Attachments: hadoopit.patch, start.sh, stop.sh > > > Currently, hadoop is a set of scripts, configurations, and jar files. It > makes it a pain to install on compute and datanodes. It also makes it a pain > to setup clients so that they can use hadoop. Everytime things are updated > the pain begins again. > I suggest that we should be able to build a single Jar file that has a > Main-Class defined with the configuration built in so that we can distribute > that one file to nodes and clients on updates. One nice thing that I haven't > done would be to make the jarfile downloadable from the JobTracker webpage so > that clients can easily submit the jobs. > I currently use such a setup on my small cluster. To start the job tracker I > used "java -jar hadoop.jar -l /tmp/log jobtracker" to submit a job I use > "java -jar hadoop.jar jar wordcount.jar". I used the client on my linux and > Mac OSX machines and I'll I need installed in java and the hadoop.jar file. > hadoop.jar helps with logfiles and configurations. The default of pulling the > config files from the jar file can be overridden by specifying a config > directory so that you can easily have machine specific configs and still have > the same hadoop.jar on all machines. > Here are the available commands from hadoop.jar: > USAGE: hadoop [-l logdir] command > User commands: > dfs run a DFS admin client > jar run a JAR file > job manipulate MapReduce jobs > fsck run a DFS filesystem check utility > Runtime startup commands: > datanode run a DFS datanode > jobtracker run the MapReduce job Tracker node > namenode run the DFS namenode (namenode -format formats the FS) > tasktracker run a MapReduce task Tracker node > HadoopLoader commands: > buildJar builds the HadoopLoader jar file > conf dump hadoop configuration > Note, I don't have the classes for hadoop streaming built into this Jar file, > but if I had that would also be an option (it checks for needed classes > before displaying an option). It makes it very easy for users that just write > scripts to use hadoop straight from their machines. > I'm also attaching the start.sh and stop.sh scripts that I use. These are the > only scripts I use to startup the daemons. They are very simple and the > start.sh script uses the config file to figure out whether or not to start > the jobtracker and the nameserver. > The attached patch adds the HadoopIt patch, modifies the Configuration class > to find the config files correctly, and modifies the build to make a fully > contained hadoop.jar. To update the configuration in a hadoop.jar you simply > use "zip hadoop.jar hadoop-site.xml". -- This message is automatically generated by JIRA. - If you think it was sent incorrectly contact one of the administrators: http://issues.apache.org/jira/secure/Administrators.jspa - For more information on JIRA, see: http://www.atlassian.com/software/jira
