Top "Mapreduce" questions

MapReduce is an algorithm for processing huge datasets on certain kinds of distributable problems using a large number of nodes

hadoop java.net.URISyntaxException: Relative path in absolute URI: rsrc:hbase-common-0.98.1-hadoop2.jar

I have a map reduce job that connects to HBASE and I can't figure out where I am running into …

java hadoop mapreduce hbase bulkloader
What are SUCCESS and part-r-00000 files in hadoop

Although I use Hadoop frequently on my Ubuntu machine I have never thought about SUCCESS and part-r-00000 files. The output …

hadoop mapreduce
Fast way to find duplicates on indexed column in mongodb

I have a collection of md5 in mongodb. I'd like to find all duplicates. The md5 column is indexed. Do …

mongodb mapreduce
What is the purpose of "uber mode" in hadoop?

Hi I am a big data newbie. I searched all over the internet to find what exactly uber mode is. …

hadoop mapreduce
MongoDB: Terrible MapReduce Performance

I have a long history with relational databases, but I'm new to MongoDB and MapReduce, so I'm almost positive I …

mongodb mapreduce nosql
Sorting large data using MapReduce/Hadoop

I am reading about MapReduce and the following thing is confusing me. Suppose we have a file with 1 million entries(…

java hadoop mapreduce
combiner and reducer can be different?

In many MapReduce programs, I see a reducer being used as a combiner as well. I know this is because …

mapreduce reducers combiners
YARN Resourcemanager not connecting to nodemanager

thanks in advance for any help I am running the following versions: Hadoop 2.2 zookeeper 3.4.5 Hbase 0.96 Hive 0.12 When I go to …

hadoop mapreduce yarn resourcemanager
Advantages of using NullWritable in Hadoop

What are the advantages of using NullWritable for null keys/values over using null texts (i.e. new Text(null)). …

java hadoop mapreduce
hadoop mapreduce: java.lang.UnsatisfiedLinkError: org.apache.hadoop.util.NativeCodeLoader.buildSupportsSnappy()Z

I am trying to write a snappy block compressed sequence file from a map-reduce job. I am using hadoop 2.0.0-cdh4.5.0, …

java hadoop mapreduce sequencefile snappy