Questions tagged [hdfs]

For questions regarding the Hadoop distributed file system (HDFS) which is part of the Apache Hadoop project.

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208 views

Optimal RAID configuration for EC2 instance store used for HDFS

I'm trying to determine if there is any practical advantage to configuring a RAID array on the instance store of a 3x d2.2xlarge instances being used for HDFS. Initially I planned to just mount each ...
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73 views

HDP cluster + data node machines + End of File Exception between local host is

we have small HDP cluster with 3 data-nodes machines HDP version is - 2.6.5 from the data-node machines we can see the following logs the main exception is about - java.io.EOFException: End of ...
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39 views

What is the suggested I/O scheduler to improve disk performance on HDFS file-system

What is the recommended I/O scheduler for HDFS file-system we have hadoop cluster with datanodes machines and we want to know the right configuration for I/O scheduler I/O scheduling in Linux ...
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30 views

HDFS on docker containers - is it possible?

we are using Hadoop cluster based on HDP version - 2.6.5 with ambari platform we want to know if we can use the following HDFS components on docker containers as: journal nodes ZK fail controller ...
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1answer
161 views

List all files in hdfs directory

Due to some error at one component, files in HDFS got accumulated and the number is huge i.e 2123516. I want to list all files and want to copy their name in one file but when I run the following ...
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84 views

AWS FSx for lustre with S3 vs EMR (with EMRFS) for spark jobs

We are currently using EMR for easy job submission for our spark jobs. Recently I came across the "FSx lustre + S3" solution that is being advertised as ideal for HPC situations. EMRFS however is also ...
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56 views

HDFS compatibility with different of disks size on datanode machines

We have HDP cluster version 2.6.5 , with data node machines ( HDFS ) hdfs version Hadoop 2.7.3.2.6.5.0-292 Subversion git@github.com:hortonworks/hadoop.git -r ...
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1answer
71 views

is it possible mix different RHEL OS version in hadoop cluster?

we are using the following HDP cluster with ambari , list of nodes and their RHEL version 3 masters machines ( with namenode & resource manager ) , installed on RHEL 7.2 312 DATA-NODES machines ...
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18 views

how to recover HDP cluster by installing HDP from scratch and save data-node disks and kafka disks data

I want to ask this important question lets say we have the following: HDP cluster with : 3 masters machine ( active/standby name-node ) , ( active/standby resource manager ) 3 datanode machines ...
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108 views

HDFS block deletion speed - cause, expectance, tuning?

I have a small (testing) HDFS cluster which I use as snapshot backup space for Flink. Flink creates and deletes roughly 1000 (small) files per second. The namenode seems to handle this without ...
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55 views

Any benefits of ZFS over EXT4 for data stream processing on top of HDFS?

I'm working on a data stream processing project in which i will be using Apache Flink and Apache Spark and I want to use HDFS for storage. The development and testing will be done on a single node ...
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16 views

DLP: How to restrict user from downloading data through Putty, SSH, SCP, Sqoop etc from Hadoop cluster

We need to enforce some controls to restrict users the capability of downloading data from hadoop via a variety of channels below (least but not all): Putty/SSH SCP Sqoop 1/2 Spark 1/2 Hue/Impala Hue/...
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86 views

HDFS NFS gateway read Input/output error

I have enabled the HDFS NFSv3 gateway on our HDFS cluster through official documentation. Everything works well except for one Ubuntu 16.04 server machine. The following is the kernel, mount and ...
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1answer
195 views

HDFS balancing , how to balanced hdfs data?

we have Hadoop version - 2.6.4 On the datanode machine we can see that hdfs data isn’t balanced On some disks we have different used size as sdb 11G and sdd 17G /dev/sdd 20G 3.0G 17G 15% /grid/...
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101 views

Hadoop: Failed to start backup node, bad state: DROP_UNTIL_NEXT_ROLL

I have created a small Hadoop cluster setup with 1 NameNode and 1 DataNode to get hands-on. below is my configuration files: Core-site.xml <property> <name>fs.defaultFS</name> ...
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88 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 ...
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106 views

ambari cluster + when need to set Block replication to 1

We get the following in Spark logs: java.io.IOException: Failed to replace a bad datanode on the existing pipeline due to no more good datanodes being available to try. (Nodes: current=[...
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36 views

Datanode machines disks size

is it important that ( workers ) datanode machines disks will be with the same size? for example we have ambari cluster with 3 workers machines ( datanode machines ) each datanode machine have 10 ...
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1answer
359 views

what is effected when running - hadoop namenode -format

we have amabri cluster ( version 2.6 ) with 24 workers machines we want to run following commands only on worker23 machine ( because problem on worker23 ) , dose these commands effected on all ...
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43 views

How to prevent arbitrary executable execution on hadoop cluster

I am involved with configuring a Hadoop cluster for complete auditability and security. I am new to the Hadoop ecosystem, but I have a decent idea of the basics. I have a few concerns for which I hope ...
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1answer
10k views

mount.nfs: mount system call failed

I am trying to mount hdfs on my local machine running Ubuntu using the following command :--- sudo mount -t nfs -o vers=3,proto=tcp,nolock 192.168.170.52:/ /mnt/hdfs_mount/ But I am getting this ...
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1answer
629 views

copying files in hdfs stalls

Have a 35 node cluster with a high number of blocks in it: ≈450K blocks per data node. After configuration change (which contained rack reassignments and NameNode Xmx increase) HDFS became a problem. ...
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43 views

how to install hadoop2.4.1 in windows with spark 2.0.0

i want to setup a cluster using hadoop in yarn mode..i want to use spark API for map-reduce and will use spark submit to deploy my applications..i want to work on cluster..can anyone help me how to ...
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153 views

How can I launch hdfs on Mesos without DC/OS?

From my understand DC/OS is a freemium managed service. Because I'd rather just have a raw Mesos implementation, I'd rather not be dependent on DC/OS and so I just want to know how to implement HDFS ...
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14 views

Need to set 000 permission to specific hdfs data block through commandline

I am trying to set the “000” permission to the specific block. I used below command to find the block information: su - hdfs -c "hdfs fsck -locations -files -blocks /user/rohit/...
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1answer
1k views

Running HDFS with only 1 data node - appending fails

I'm trying to test some services that require HDFS using Docker Compose. Since the services being tested, namenode, and data node(s) will all be running on the same physical machine (dev laptop), it ...
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2answers
793 views

Can HDFS be installed on ZFS or BTRFS hard disks?

I am new to hadoop and confused about how HDFS works with ZFS or BTRFS. Can physical drives be mounted using ZFS and then have HDFS installed on top of ZFS? Or can HDFS be installed directly?
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17 views

Is it possible to configure hdfs in a federation mode and in an HA mode in the same time?

I don't understand if it possible to configure HDFS in both modes in the same time. Does it make sense? Can somebody show a simple configuration of HDFS in both modes? (nameNode1, nameNode2, ...
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1answer
605 views

Why does DFSZKFailoverController kills Namenode process in hadoop?

I try to configure hadoop high availability cluster by following this tutorial: http://www.edureka.co/blog/how-to-set-up-hadoop-cluster-with-hdfs-high-availability/ When I follow that article I faces ...
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578 views

Zombie process blocking port when restarting Hadoop (Secondary) Namenode

I'm having weird issues with the Hadoop Namenode and Secondary Namenode. Our HDFS cluster runs smoothly most of the time. But every now and then, either the Primary Namenode freezes (crashing the ...
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2k views

HDFS performances on apache spark

I have several issues related to HDFS, that may have different roots. I'm posting as much information as I can, with the hope that I can get your opinion on at least some of them. Basically the cases ...
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1answer
4k views

Upload large files with curl without RAM cache.

I'm using curl to upload large files (from 5 to 20Gb) to HOOP based on HDFS (Hadoop Cluster) as follows: curl -f --data-binary "@$file" "$HOOP_HOST$UPLOAD_PATH?user.name=$HOOP_USER&op=create" ...
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1answer
3k 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 collector....
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1answer
65 views

Viewing NxN network traffic in a distributed system

I have a Hadoop cluster set up, and I would like to view the network usage between all nodes in this cluster, i.e. if I have N nodes, I want to see NxN network connections so that I can view all ...
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3answers
17k 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
2k 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
1k views

HBASE Space Used Started Climbing Rapidly

Update 4,215: After looking at space usage inside of hdfs, I see that .oldlogs is using a lot of space: 1485820612766 /hbase/.oldlogs So new questions: What is it? How do I clean it up? How do ...
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491 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
718 views

Linux Network tuning to prevent tcp rcvpruned and backlogdrop?

My datanodes in my hbase cluster are triggering some tcp rcvpruned and backlog drops from time to time: It seems to be there are at least two angles to approach this at: Tune HBase/HDFS etc... so ...
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1answer
2k 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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3k views

“The volume for a file has been externally altered …” and setting file sizes on write to NFS from Windows

I have set up NFS access to HDFS. I can connect to the default root share from both Windows and Linux clients and all clients can read from the share. Writing from the Linux client is also ok. When ...
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2answers
3k views

Disable The Under Replicated Blocks Alert in Cloudera Manager

I have a single server Hbase cluster that I am only using as the sink end of HBase replication. Therefore I don't want to replicate any blocks within this cluster (since the source has replicated ...
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2answers
11k 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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2answers
4k 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: /etc/hadoop/...
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0answers
2k views

java.lang.NullPointerException When Doing A Read in HDFS

I have had a 10 node HBase cluster up and running for the past 4 months. The cluster was setup on VMs in a corporate environment which I do not control, but everything has been working great...until ...
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4answers
7k 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
61 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 /...
3
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1answer
1k views

btrfs: Looking for experience on btrfs error modes on bad sectors / read errors / medium erros

While running a Hadoop cluster that uses HDFS (so data is already replicated 3x) we experience often issues with ext4 because some bad sectors (the filesystem is unable to read or write to them) ...
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1answer
458 views

Additional Storage Options for Hadoop HDFS Nodes

We have a small production Cloudera distribution Hadoop cluster(14 nodes, but growing). As we have expanded our usage of this cluster we have found that disk storage is our biggest blocker and ...
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1answer
2k views

Change existing linux user's uid in LDAP but hdfs seems does not recognize it

I have set up a hadoop 1.2.1 environment on centos 6. I also use nfs-proxy that mount ndfs to local file system so that I can access the files inside hdfs locally. It works perfectly until today, I ...