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Showing posts from January, 2016

Quick guide to install GitLab (Community Edition)

A quick tutorial on how to install GitLab ( https://about.gitlab.com/ ) CE (Community Edition). The steps described in this post have been verified and tested on Red Hat Linux Server 6.x 64-bit, but they should work also on Red Hat 7.x, CentOS 6.x+, Oracle 6.x+ and Scientific Linux 6.x+ distributions.   Installation. We are going to use the Omnibus package. It includes almost all of the packages needed, but OpenSSH and Postfix. These are the installation steps (all of the commands below need to be issued with a user having root privileges.):  - Check whether the following prerequisites are present in the system: OpenSSH Server ( http://www.openssh.com/ ) and Postfix ( http://www.postfix.org/ ). If not, before proceeding in the GitLab installation, please install them following the official documentation and the specific steps for your Linux distribution.  - Download the Omnibus package (the command below is for CentOS 6.x/Red Hat 6.x/Oracle/Scientific Linux distribu...

HDFS file commands quick reference

Here's a quick reference of the most frequently used (and useful) HDFS (Hadoop Distributed File System) commands to manage files. $HADOOP_HOME/bin/hadoop fs -ls / Lists all of the files in the root HDFS directory. $HADOOP_HOME/bin/hadoop fs -ls /rawdata/server01 Lists all of the files in the HDSF directory at the given path. $HADOOP_HOME/bin/hadoop fs -mkdir /rawdata/ Creates a new directory in HDFS. $HADOOP_HOME/bin/hadoop fs -put /home/user/importdir/*.txt /rawdata/ Copies files from a local directory to HDFS at the specified path. The destination directory should have been created preliminarily. $HADOOP_HOME/bin/hadoop fs -get /rawdata/test01.txt /home/user/importdir/ Copies files from HDFS back to the local filesystem. $HADOOP_HOME/bin/hadoop fs -cp /rawdata/test01.txt /rawdatabackup/test01.txt Copies files within HDFS. $HADOOP_HOME/bin/hadoop fs -rm /rawdata/*.txt Deletes files from a HDFS directory. $HADOOP_HOME/bin/hadoop fs -rm -r /rawdata Deletes a ...