I have a compressed Hadoop SequenceFile from a customer which I\'d like to insp开发者_如何学JAVAect. I do not have full schema information at this time (which I\'m working on separately).
I have a file in hdfs with 100 columns, which i want to proces using pig.I want to load this file into a tuple 开发者_如何转开发with columns names in a separate pig script, and reuse this script from
It looks like Hadoop MapReduce requires a key value pair structure in the text or binary text. In reality we might have files to be split into chunks to be processed. But the keys may be
As we know Hadoop groups values with per key and sends them to same reduce task. Suppose I have next lines in file on hdfs.
I\'d like to implement a MultithreadMapper for my MapReduce job. For this I replaced Mapper with MultithreadMapper in a working code.
As part of my Java mapper I have a command executes some standalone code on a local slave node.When I run a code it executes fine, unless it is trying to access some local files in which case I get th
I am a bit confused, in the Hadoop cluster setup, in section \"Real-World Cluster Configurations\", an example is given where properties like io.sort.mb & io.sort.factor goes in core-site.xml. But
This question already has answers here: Closed 11 years ago. Possible Duplicate: hadoop-streaming example failed to run - Type mismatch in key from map
I\'m writing a Hadoop/HBase job. I needed to transfo开发者_高级运维rm a Java String into a byte array. Is there any differences between Java\'s String.getBytes() and Hadoop\'s Bytes.toBytes()?Accordin
According to the Hadoop : The Definitive Guide. The new API supports both a “push” and a “pull” style of iteration. In both APIs, key-value record pairs are pushed to the mapper, but i开发者_Go百
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