Linux Kernel 4.9.60 Release

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This post summarizes Linux Kernel new features, bugfixes and changes in Linux 4.9.60 Release. Linux 4.9.60 Release contains 24 changes, patches or new features. In total, there are 64,224 lines of Linux source code changed/added in Linux 4.9.60 release compared to Linux 4.9 release. To view the source code of Linux 4.9.60 kernel release online,
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Installing R and RStudio Server in Ubuntu Linux 20.04

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R is a language and environment for statistical computing and graphics, providing a wide variety of statistical and graphical techniques. The R environment is open source software under GPL. R has rich software packages and is widely used for statistical analysis. RStudio Server is an R integrated development environment (IDE) that provides many useful features
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The cultural impact of cloud technology

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Cloud technology is one of the latest forms of technology. A cloud is a place where exactly the data is stored. Also, the cloud is the place where the data is managed and processed. Cloud ensures that the data managed on a cluster or the network of servers. All of these servers are available remotely
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What is the Future of Big Data Analytics and Hadoop?

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Big Data has taken a lead in the IT industry and has played a significant role in the Business growth and decision-making processes that gives you an edge over the competitors. This is equally applicable to the organizations as well as professionals existing in the analytics domain. Big Data Analytics bring an ocean of opportunities
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How to handle missing blocks and blocks with corrupt replicas in HDFS?

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One of HDFS cluster’s hdfs dfsadmin -report reports: Under replicated blocks: 139016 Blocks with corrupt replicas: 9 Missing blocks: 0 The “Under replicated blocks” can be re-replicated automatically after some time. How to handle the missing blocks and blocks with corrupt replicas in HDFS? Understanding these blocks A block is “with corrupt replicas” in HDFS
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How to email admins automatically after a Linux server starts?

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Managing a cluster of servers, I would like to notified when a server is started. How to make the Linux servers email me or other admins automatically after they are started? I did this by adding a crontab entry on each servers like @reboot date | mailx -S smtp=smtp://smtp.example.com -s “`hostname` started” -r zma@example.com zma@example.com
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How to add a new HDFS NameNode metadata directory to an existing cluster?

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We have a running HDFS cluster. Currently, the NameNode metadata data directory has only one directory configured in hdfs-site.xml: <property> <name>dfs.namenode.name.dir</name> <value>file:///home/hadoop/hdfs/</value> <description>NameNode directory for namespace and transaction logs storage.</description> </property> We would like to add a new directory for dfs.namenode.name.dir to make replicas of the metadata on a separated disk for higher data reliability.
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How to check the replication factor of a file in HDFS?

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A related question: how to find the replication factors of files in a HDFS cluster? method 1: You can use the HDFS command line to ls the file. The second column of the output will show the replication factor of the file. For example, $ hdfs dfs -ls /usr/GroupStorage/data1/out.txt -rw-r–r– 3 hadoop zma 11906625598 2014-10-22
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How to change an running HDFS cluster’s replication factor?

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Now, I have a running HDFS cluster storing lost files. I want to change its default replication factor. How to change it? What will happen after it is changed? For example, I change from 2 to 3. Will HDFS automatically re-replicate the data chunks? First, the replication factor is client decided. Second, the replication factor
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How to balance DataNode storage in HDFS?

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As nodes are added and deleted in a Hadoop cluster. Storage usage across DataNodes may be different. Some DataNodes’ disks are almost used up while some others’ are almost empty. How to balance data across DataNodes in HDFS? Hadoop provides the balancer to redistribute the data. Brief introduction to balancer in Hadoop: balancer. The design
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Random string password generator in Scala

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Managing our research cluster, I frequently need to generate some string for new users’ password. How to generate them automatically and randomly in Scala? The passwords need characters ‘a’ – ‘z’, ‘A’ – ‘Z’ and ‘0’ – ‘9’ only. This piece of code works very well for me: def randomString(len: Int): String = { val
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Systems Conferences

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Which ones are good systems conferences? Top ones by ACM and USENIX: OSDI: https://www.usenix.org/conferences/byname/179 SOSP: http://sosp.org/ Other SIGOPS Events: http://www.sigops.org/conf-sponsored.html EuroSys: http://www.eurosys.org/ SoCC: http://www.socc2013.org/ (SoCC 2013) ASPLOS: http://www.sigplan.org/Conferences/ASPLOS/Main VEE: http://www.sigplan.org/vee.htm USENIX ATC: https://www.usenix.org/conferences/byname/131 NSDI: https://www.usenix.org/conferences/byname/178 IEEE Conferences: ICDCS: http://www.temple.edu/cis/icdcs2013/ (2013) IPDPS: http://www.ipdps.org/ Other related ones and workshops: HPCA: Search HPCA ConferenceSC: http://www.supercomp.org/IEEE CLUSTER: http://www.clustercomp.org/ HotCloud:
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Quartz Implementation in Java

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In this post, java development India based experts will explain the concept of Quartz. You will also learn the method of setting up the Quartz in this article. You can ask experts if anything bothers you. Technology Quartz is the open source Java technology for scheduling background jobs. If we want to execute the task
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Three Methods of Executing Commands on Many Nodes in Parallel via SSH on Linux

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It is common to execute commands on many nodes/hosts via SSH for managing a cluster of Linux servers. On Linux, there are many choices for this task. Generally, to run commands on many nodes, there are two modes: serial mode and parallel mode. In serial mode, the command is executed on the node one by
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