A Technical I.T./DevOps Blog
Problem scenario
You try to run a compiled Java program. You see the .class file as a result of your compilation. But when you run java ContInt.class, you get this error:
“Error: Could not find or load main class ContInt.class”
How do you run the bytecode (to have your Java program execute after compilation)?
Solution
Omit the “.class” when you run the “java” command.
…
Continue reading “How Do You Run (Execute) a Java Program That Compiled Successfully?”
Problem scenario
One of the following applies:
1. You want to install Ansible on an AWS instance of RHEL.
2. You want to install Ansible on a GCP server running RHEL.
How do you do either of these things?
Solution
These directions should work for other RedHat distributions of Linux (e.g., Fedora or CentOS) that are not AWS servers as long as the server has 2 GB of RAM.
…
Continue reading “How Do You Install Ansible on an AWS Instance of RedHat Enterprise Linux?”
Problem scenario
You want to install Apache web server on a CentOS, Red Hat Enterprise Linux or Fedora server. What do you do to install it and have the service start running?
Solution
Run these commands:
sudo yum -y update
sudo yum -y install httpd
sudo service httpd start
…
Continue reading “How Do You Install Apache Web Server with CentOS/RHEL/Fedora?”
Problem scenario
You have Apache web server installed on Ubuntu. You cannot find httpd.conf. What do you do?
Solution
With Apache2 there is no httpd.conf file. This directory /etc/apache2/ has files like apache2.conf which is related.
…
The Accidental Administrator: Linux Server Step-by-Step Configuration Guide by Don R Crawley
Administering Apache by Mark Allan Arnold, Clint Miller, James Sheetz and Jeff D. Almeida
Apache 2 Pocket Reference: For Apache Programmers & Administrators (Pocket Reference (O’Reilly)) by Andrew Ford
Apache Administrator’s Handbook by Rich Bowen, Daniel Lopez Ridruejo and Allan Liska
Apache Cookbook: Solutions and Examples for Apache Administration by Rich Bowen and Ken Coar
Apache Essentials: Install,
…
Problem scenario
You want your PHP files (either a frontend web page or a purely backend script) to integrate with Postgres. You want .php files to log into a Postgres database to run SQL commands. How do you do this?
Solution
Install php5-pgsql or php7.0-pgsql. It depends on your version of PHP. Use this command to find out what version of PHP you have: php –version
Install this module:
…
Continue reading “How Do You Integrate PHP with Postgresql?”
Problem scenario
You want to install Apache web server on your Ubuntu Linux server. How do you do it?
Solution
As root, run this command: apt-get install apache2
To verify it is installed correctly run this: apache2 -l
To start the web service, run this: systemctl start apache2
…
Continue reading “How Do You Install Apache Web Server on Ubuntu Linux?”
Problem scenario
You have Ubuntu 14.04 or 16.x, and you want to install Vagrant 1.x. (If you have Ubuntu 16.0x or higher and want to install Vagrant 2.x, go to the very bottom.) How do you do it?
Solution
1. Run this command: sudo find / -name sources.list #find the file that governs Debian packages
3. Ignore /usr/share/doc/apt/examples/sources.list. Make a copy of the other sources.list as a back up (in case you need to rollback).
…
Continue reading “How Do You Install Vagrant on an Ubuntu Linux Server?”
In technical writing there is emphasis on clarity. Often grammar rules are not followed. The past tense of the verb run is “ran.” The past tense of the verb come is “came.” The past participle of the verb run is “run.” The past participle of the verb come is “come.” Do not confuse the past tense with the past participle.
…
Advanced Analytics with Spark: Patterns for Learning from Data at Scale by Sandy Ryza, Uri Laserson, Sean Owen and Josh Wills
Agile Data Science: Building Data Analytics Applications with Hadoop by Russell Jurney
Apache Drill: The SQL query engine for Hadoop and NoSQL by Ted Dunning, Ellen Friedman, Tomer Shiran and Jacques Nadeau
Apache Flume: Distributed Log Collection for Hadoop -Second Edition by Steve Hoffman
Apache Hadoop YARN: Moving beyond MapReduce and Batch Processing with Apache Hadoop 2 (Addison-Wesley Data &
…