Annis : Hadoop streaming potens est utilitas quae venit cum Hadoop distribution.The basic conceptus Hadoop compage est ad scindendum job,processus in parallel postea conjunge it retro ad accipiendum finem result.So duo sunt maxima components involved in hac margine,.
a) Map application
b) Reducere application
The Hadoop streaming utilitatis sino vos scribere Map / Redigo applications in quamlibet linguam quod est capax cooperante STDIN et stdout.
I read your introduction article about hadoop streaming. I found it really helpful. But I have more questions about how to use it.
One main question I want to ask is if my perl script needs more than one argument, how can I pass them to the command line?
For example, I used the following command, where I used multiple inputs to handle multiple arguments. But in fact, the data input is just the first one. All others are just some resources the perl script needs to read in to help process the first data input.
hadoop jar /usr/lib/hadoop-mapreduce/hadoop-streaming.jar -D mapred.reduce.tasks=0 -D mapred.map.tasks.speculative.execution=false -D mapred.task.timeout=12000000 -input nlp_research/edt_nlp_data/3000001.txt -input shift.txt -input lists -input dict -input nlp_research/deid-1.1/deid.config -inputformat org.apache.hadoop.mapred.lib.NLineInputFormat -output perl_output -mapper deid_mapper.pl -file deid_mapper.pl
If you can give me some guidance, that would be great!