Questions tagged [mapreduce]

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hadoop-config.sh in bin/ and libexec/

While setting up hadoop, I found that hadoop-config.sh script is present in two directories, bin/ and libexec/. Both the files are identical. While looking onto scripts, I found that if hadoop-config....
krackoder's user avatar
  • 151
4 votes
1 answer
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How do I define the timeout for bootstrap actions on Amazon's Elastic MapReduce?

How do I change the timeout for bootstrap actions on Amazon's Elastic MapReduce?
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3 votes
1 answer
725 views

Best practice for administering a (hadoop) cluster

I've recently been playing with Hadoop. I have a six node cluster up and running - with HDFS, and having run a number of MapRed jobs. So far, so good. However I'm now looking to do this more ...
user avatar
2 votes
0 answers
4k views

Hadoop Streaming with Python 3.5: java.lang.RuntimeException: PipeMapRed.waitOutputThreads(): subprocess failed with code 127

I'm trying to run my own mapper and reducer Python scripts using Hadoop Streaming on my cluster built on VMware Workstation VMs. Hadoop version - 2.7, Python - 3.5, OS - CentOS 7.2 on all the VMs. I ...
alex's user avatar
  • 21
1 vote
3 answers
950 views

Hadoop Rolling Small files

I am running Hadoop on a project and need a suggestion. Generally by default Hadoop has a "block size" of around 64mb.. There is also a suggestion to not use many/small files.. I am currently having ...
Arenstar's user avatar
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1 vote
1 answer
4k views

Hadoop FileAlreadyExistsException: Output directory hdfs://<namenode public dns>:9000/input already exists

I have Hadoop setup in fully distributed mode with one master and 3 slaves. I am trying to execute a jar file named Tasks.jar which is taking arg[0] as input directory and arg[1] as output directory. ...
Harinarayanan Mohan's user avatar
1 vote
0 answers
101 views

Sample output of Rumen or Input to Gridmix

I want to see JobHistory logs, which can be fed as input to the Rumen. More specifically, I am interested in knowing input format for the Gridmix. I tried following two things for it: 1) I found ...
PHcoDer's user avatar
  • 111
1 vote
1 answer
580 views

MapReduce job is hung after 1 of 5 reducers completed on single-node environment

I have only one Data Node on my dev environment on EC2. I ran heavy MR job and in 6 hours noticed that 100% of mappers and 20% of reducers finished (1 of reducer shows 100% competition, other ones - 0%...
Marboni's user avatar
  • 111
1 vote
0 answers
160 views

How to increase the performance on Amazon Elastic Mapreduce for job execution?

My task is: Initially I want to import the data from MS SQL Server into HDFS using SQOOP. Through Hive I am processing the data and generating the result in one table That result containing table ...
Bhavesh Shah's user avatar
1 vote
2 answers
411 views

Updating group without log out or subshell

I'm trying to run Docker on Elastic MapReduce streaming but am having trouble with a permissions issue. In my bootstrap script, I need the "hadoop" user to be part of the "docker" group (as described ...
Max's user avatar
  • 111
0 votes
1 answer
7k views

MongoDB Locking - Very, very, slow to read

This is the output from db.currentOp(): > db.currentOp() { "inprog" : [ { "opid" : 2153, "active" : false, "op" : "update", "ns" : "", ...
StuR's user avatar
  • 167
0 votes
1 answer
340 views

How to view status of recent AppEngine mapreduce jobs?

We recently upgraded our App Engine application to GAE SDK 1.9, and upgraded the older MapReduce library we'd been using to the most recent version hosted on GitHub. We now find that the old MapReduce ...
JP Lodine's user avatar
  • 101
0 votes
0 answers
220 views

Distributing Master node ssh key

For the master node to passwordless-ly ssh into the slaves, the master needs to distribute its ssh key to the slaves. Copying key using ssh-copy-id asks for the user password. If there are hundreds of ...
krackoder's user avatar
  • 151