Hadoop is an open-source solution for providing a distributed/replicated file system, a produciton grade map-reduce system, and has a series of complementary additions like Hive, Pig, and HBase to get more out of a Hadoop-powered cluster.

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24 views

Flume- Error Log while using FileChannel

I am using Flume flume-ng-1.5.0 ( with CDH 5.4) to collect logs from many Servers and Sink to HDFS Here is my configuration : #Define Source , Sinks, Channel collector.sources = avro ...
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1answer
32 views

Should I deploy hadoop on physical machines or virtual machines?

We will deploy a hadoop cluster on hundreds(say 300) of physical x86 nodes. Since we have no much production deployment experience, there is a simple question as the title we want to hear response ...
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38 views

Hadoop namenode port getting blocked

I have installed 7 VM instances of Ubuntu 14.04 LTS servers. First instance runs the namenode service and all other 6 nodes run datanode service.I think my NameNode is getting crashed or blocked due ...
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15 views

in hadoop2.3.0 in windows all cmds worked correctly but it shows error

when i put the following command it shows the error like this C:\hadoop-2.3.0\bin>hadoop -namenode format Error: Could not find or load main class SUMATHY Sumathy is my pc's name. please help ...
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6 views

Application listing in hadoop resource manager

Every time resource manager restarted, previously run applications are getting cleared from Resource manager webUI (not in Mapreduce History server). Is there anyway to keep these finished application ...
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1answer
94 views

Setting up Secure Hadoop Cluster - Kerberos security

I setup a HDP 2.2 cluster successfully (1 NM, 3 DNs and 1 client). User accounts to access HDP cluster are created in client and checked these users can submit jobs, by SSH to client node and run ...
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1answer
60 views

Hadoop on Openstack vs physical servers

I'm new to Hadoop and trying to understand how it should be installed/configured. From the documentation I see that Hadoop normally should be aware about physical servers configuration (e.g ...
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1answer
97 views

What cause this error? [closed]

I am running two docker containers one is for hadoop basic services and other is for flume. Services are running successfully. I linked two containers env variables are automatically set by docker ...
1
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1answer
503 views

How to connect two docker containers running on the same host?

I have two docker containers running docker ps results CONTAINER ID IMAGE COMMAND CREATED STATUS PORTS NAMES 0bfd25abbfc6 ...
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74 views

Hadoop HA connection issue

I am using the Azure VM to build a Hadoop HA cluster, I'm trying to set up an Active namenode and a Standby namenode. But when I finished my configurations, I found I can only access one namenode via ...
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1answer
311 views

Is there a way to grep gzipped content in hdfs without extracting it?

I'm looking for a way to zgrep hdfs files something like: hadoop fs -zcat hdfs://myfile.gz | grep "hi" or hadoop fs -cat hdfs://myfile.gz | zgrep "hi" it does not really work for me is there ...
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1answer
185 views

Hadoop: How to configure failover time for a datanode

I need to re-replicate blocks on my HDFS cluster in case of a datanode is failing. Actually, this appears to already happen after a period of maybe 10min. However, I want to decrease this time, but ...
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2answers
48 views

How to specify hard disk for hadoop cluster?

I installed Hadoop on one Azure VM, and it works fine by using its OS disk. However, I attached one hard disk to my VM, and I want to know how to configure Hadoop to only use this new hard disk as its ...
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82 views

which pig version is best for hadoop 2.5.0 with yarn?

I am using hadoop 2.5.0 with yarn enabled. I have used pig versions 0.11.0, 0.13.0, 0.14.0 with hadoop 2.5.0 but getting following error. 2015-01-06 19:21:26,835 FATAL [main] ...
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2answers
567 views

“sudo apt-get remove hadoop” is not removing package

I am trying to uninstall Cloudera Hadoop from my Ubuntu System. For this I tried sudo apt-get remove hadoop command but this command is failing with following message: ...
9
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2answers
147 views

Moving the SecondaryName Node in a Cloudera HBase Cluster

I deployed the secondary namenode on the same machine is my main namenode: This is wrong for performance and durability reasons (the secondary name node isn't a hot spare, but it does have a copy ...
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1answer
97 views

Ambari/Nagios overwrites hadoop-services.cfg file on startup

When I shut down Nagios from the Ambari Web UI, modify the file hadoop-services.cfg, save it and open it, new settings are there. However, when I start the Nagios again (from the Ambari Web UI) and ...
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0answers
135 views

How to force HDFS to use LDAP user's UID

I have a cloudera cluster with HDFS and Hue services and I'm trying to unify the authentication using LDAP. I have my LDAP server running thanks to 389-ds (not sure if is the best way) and I can log ...
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1answer
98 views

Does Active Directory alone is not enough to secure hadoop?

I am trying to secure Hadoop environment installed in windows. So basically I started to analyse how to secure a Unix-based hadoop cluster. Have gone through various links related to Kerberos and ...
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31 views

Hadoop lib syncronisation

I'm using Cloudera CDH5. I try to work with Twitter Anlyse . After building flume-sources-1.0-SNAPSHOT.jar and hive-serdes-1.0-SNAPSHOT.jar I placed this jars in manually in directories on all ...
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1answer
84 views

How to access hadoop remotely

I have installed Hadoop on open-stack CentOS guest VM. I am able to open the site (From 192.168.0.10, VM-1) http://localhost:50070 http://192.168.0.10:50070 But not able to access the same from a ...
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208 views

Error: E0701 : E0701: XML schema error while running custom executor

I am trying to test the custom executor sample found here http://www.infoq.com/articles/ExtendingOozie and another sample about ftp action for extending Oozie. In both cases I cannot run the test. ...
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422 views

Hadoop data node start fails with error: java: cannot execute: Permission denied

I am facing an error in starting a Hadoop Data Node from Ambari WEB interface, and I need your help to resolve this. As always the error message is very comlex and long, but first thing first. Even ...
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1answer
42 views

How to know which script or executable is linked with a metric in ganglia?

I have just started to explore ganglia and my question is "How to know which script or executable is linked with a metric in ganglia?" The fact is that I don't know much about ganglia. I have good ...
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114 views

Running multiple Hive metastores against a single HDFS

I'm investigating the possiblity of implementing dedicated Hive instances, each with their own metastore residing on their own work node outside of the cluster, but accessing the same data on a shared ...
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1answer
215 views

slaves get a connection timed out with hdfs

I have 3 node instances - master, slave1 and slave2 SSHing between these nodes works fine. Here is the processes that starts on each node when I say ./sbin/start-dfs.sh master: SecondaryNameNode ...
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1answer
39 views

Unable to connect to Amazon EC2 and run pig

I have made an EC2 key pair and saved it to a location under my home directory on mac. Also I have changed permissions with 'chmod 600 /path/to/saved/keypair/file.pem'. Now I have followed the ...
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2answers
57 views

Unable to setup a connection to Amazon EC2 and run pig

I have made an EC2 key pair and saved it to a location under my home directory on mac. Also I have changed permissions with 'chmod 600 /path/to/saved/keypair/file.pem'. Now I have followed the ...
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1answer
431 views

Rhadoop hdfs.init() Error

I recently installed CDH5.1.0 along with R 3.1.*, and I got rmr2, rJava, and rhdfs all installed properly. (along with the required packages and set the required environment variables) After some ...
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99 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 ...
2
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2answers
402 views

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 ...
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2answers
2k views

error while running any hadoop hdfs file system command

I am very new to hadoop and referring to the "hadoop for dummies" book. I have a VM with following specs: hadoop version 2.0.6-alpha bigtop os centos The problem is when I run any hdfs file system ...
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136 views

hadoop hbase environment variables

I tried to setup a 4 node Hadoop cluster using CDH4.7. The cluster is up and running fine and when I submit a word count MR job it completed successfully but when I am submitting an MR job to insert ...
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1answer
204 views

Best practices - Conditionals for Chef resources without guard attributes?

We are setting up a cluster using Apache Ambari. Our Chef run is interrupted by the need to use Ambari to provision the Hadoop cluster. Current installs are a three part process: Initial Chef run ...
2
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0answers
109 views

Hbase block locality index is always 0

I have a Hbase (v 0.94.19 with Hadoop 1.2.1) setup with one master machine and two region servers. Each region server has 16 GB heap (6.4 GB cache, 4.0 GB memstore) and 1.6 TB (2 X 800 GB) SSD disk ...
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1answer
652 views

HDFS' ZKFC service unable to start

Introduction CDH4's ZooKeeper Failover Controller (ZKFC) has been installed. Starting the ZKFC service: [vagrant@localhost ~]$ sudo service hadoop-hdfs-zkfc start Starting ...
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2answers
660 views

Unable to convert HDFS from non-HA to HA

Introduction Aim: Convert HDFS from non-HA to HA. Method: According to this documentation it should be possible to convert HFDS from non- to HA by implementing following configuration: ...
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0answers
80 views

Can I use Yarn to dynamically assign nodes for map reduce tasks

When I use Hadoop for executing the Map reduce tasks, I am unable to find the API to allow me assign the compute nodes for executing the task. Is there any simple way to let Resource manager ...
2
votes
1answer
3k views

Command to determine whether a ZooKeeper Server is a Leader or a Follower

Introduction A ZooKeeper Quorum consisting of three ZooKeeper servers has been created. The zoo.cfg located on all three ZooKeeper servers looks as follows: maxClientCnxns=50 # The number of ...
4
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1answer
1k views

Could not start ZK at requested port of 2181, while export HBASE_MANAGES_ZK=false

Problem The first aim was to run HBase standalone. Navigating to ip:60010/master-status is succesfull once HBase has been started. The second aim is to run a distinct ZooKeeper quorum. ZooKeeper has ...
4
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1answer
167 views

Does Cloudera Manager need ongoing Root Access?

When installing Cloudera Manager 4, it asks for the root password on a passwordless sudo user to install packages. Does this account need to be retained, or is it just for initial setup?
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237 views

Can I change my hive external table storage format without affecting its partitions?

I want to change my external table storage format from text file to ORC file. I already added partitions around 500 for the external table stored as 'TEXTFILE'. If I simply create another external ...
1
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1answer
521 views

Cloudera Hadoop superuser group

I'm trying to create a group on one of my datanodes that will have superuser privileges for hdfs and associated fs commands. So far I have: Checked to see that ...
4
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3answers
512 views

In Hadoop, how to show current process of -copyFromLocal

I am still a newbie learner of Hadoop, and this time I was trying to process a 106GB file. I used -copyFromLocal to copy that big file to my Hadoop DFS, but since the file is big I have to wait for a ...
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0answers
26 views

When and how are initial directories created in HDFS

I have a Hadoop setup in which the configured HDFS umask is 027 instead of the default one. Some of the initially created directories have correct permissions (like tmp drwxrwxrwx) but others such as ...
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184 views

How to start hadoop on CentOS

I have installed hadoop using Yum on CentOS: yum install hadoop Now I want to start hadoop but cannot find the start-all.sh script mentioned on many blogs and wiki pages such as ...
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2answers
3k views

“/usr/bin/env: bash: No such file or directory” during puppet exec command

I am setting my first steps into puppet. I am trying to setup ambari. This is my puppet config: exec { "ambari-repo": command => "curl ...
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1answer
233 views

Cannot print hdfs topology when using viewfs:/// as fs.defaultFS

I am using Rack Awareness technology in HDFS, I can use the following command to get topology: hdfs dfsadmin -printTopology Today, after setting up HDFS Federation and use viewfs instead of hdfs ...
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0answers
607 views

Encounter an error when configuer secure hadoop : org.apache.hadoop.security.AccessControlException

I try to configure secure hadoop with kerberos. I have started KDC server , generated and copy related keytab to corresponding node. kerberos can work normally (use kinit) but when i try to start ...
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0answers
67 views

Hadoop - On the Wire Performance Monitoring?

I have been tasked with implementing an 'on the wire' monitoring solution for a large Hadoop installation. The source of data will be a combination of taps and SPANs throughout the environment. My ...