The Geek Diary

Archives for August 2018

CCA 131 – Perform OS-level configuration for Hadoop installation

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Note: This post is part of the CCA Administrator Exam (CCA131) objectives series In the last post we have setup the local CDH repository. But before we can perform any installation or even before setting up the repositoy you must perform few OS-level configurations. The OS-level configuration includes: Enabling NTP Configuring Network Names (hostnames/FQDNs) Disabling […]

Preparing for the CCA Administrator Exam (CCA131)

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CCA 131 or Cloudera Administration Certification Exam is the most valued certification exam in the Hadoop world. The exam is practical oriented with sample scenarios to work upon. Number of Questions: 8–12 performance-based (hands-on) tasks on pre-configured Cloudera Enterprise cluster. Time Limit: 120 minutes Passing Score: 70% Language: English Price: USD $295 Exam Objectives Install […]

CCA 131 – Set up a local CDH repository

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Note: This post is part of the CCA Administrator Exam (CCA131) objectives series CDH can be installed using one of the following two methods: Installation using the operating system’s package manager (e.g. yum) Installation using Cloudera Manager Note: Make sure you have followed the post “Perform OS-level configuration for Hadoop installation” before you proceed to […]

How to measure NIC Performance/Throughput in Solaris 11 using iftop

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Monitoring network connections certainly can be frustrating, mainly because they can be established and then disappear within a matter of seconds. In this post, we will show you how to achieve a Zen-like approach to monitoring network connections on your servers using a command line–based tool called iftop. iftop is to networks what top is […]

10 useful cron examples to schedule jobs in Linux

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The GNU/Linux system supports several utilities for scheduling tasks. The cron utility is the most widely supported. It allows you to schedule tasks to be run in the background at regular intervals. The cron utility uses a table (crontab) with a list of scripts or commands to be executed and the time when they are […]

How to install rsyslog7 when rsyslog5 is already installed in CentOS/RHEL

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The Problem When attempting to install rsyslog7, it fails with a conflict error with rsyslog. # yum install rsyslog7 … Resolving Dependencies –> Running transaction check —> Package rsyslog7.x86_64 0:7.4.10-7.el6 will be installed –> Processing Dependency: libestr.so.0()(64bit) for package: rsyslog7-7.4.10-7.el6.x86_64 –> Running transaction check —> Package libestr.x86_64 0:0.1.9-2.el6 will be installed –> Processing Conflict: rsyslog7-7.4.10-7.el6.x86_64 […]

Understanding How an Email System Works

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E-mail has become an extremely popular communication tool. A solid understanding of email system concept helps system administrators to investigate various kinds of issues with the email system. 1. How does an email travel The diagram below shows a typical sequence of events that takes place when Alice composes a message using her mail user […]