Fernando Aleman fernandoaleman

Problem

Chef command warnings concerning already initialized constants

warning: already initialized constant Etc::SC_AIO_LISTIO_MAX
warning: already initialized constant Etc::SC_AIO_MAX
warning: already initialized constant Etc::SC_AIO_PRIO_DELTA_MAX
warning: already initialized constant Etc::SC_ARG_MAX
warning: already initialized constant Etc::SC_ATEXIT_MAX

Problem

Installing mysql2 gem errors on MacOS Catalina with MySQL 5.7.

Solution

Make sure openssl is installed on Mac via Homebrew.

brew install openssl

MySQL Master-Slave Replication on CentOS 7

Install and configure MySQL with master-slave replication. The benefits of this include high availability, backups, disaster recovery and reporting.

For tutorial purposes, we will be using one master node and one slave node.

Master Node: 10.0.0.10
Slave Node:  10.0.0.11

Reduce LVM Partition on CentOS 7

Sometimes when creating a new CentOS 7 server, the drive is partioned with the root, boot and swap, and then all the rest of the space is given to the home directory.

Here, we are going to reduce the size of the /home partition and allocate the remaining space back to the root partition.

List Block Devices

List the current block devices

Install RabbitMQ on CentOS 7

sudo yum -y install epel-release
sudo yum -y update

Install Erlang

Download repository

For MacOS Catalina, visit Install mysql2 on MacOS Catalina

Problem

Installing mysql2 gem errors on MacOS Mojave.

Solution

Make sure openssl is installed on Mac via Homebrew.

	#!/bin/sh
	# you might want to add some user authentication here
	mysql -e "show variables; show status" \| awk '
	{
	VAR[$1]=$2
	}
	END {
	MAX_CONN = VAR["max_connections"]
	MAX_USED_CONN = VAR["Max_used_connections"]
	BASE_MEM=VAR["key_buffer_size"] + VAR["query_cache_size"] + VAR["innodb_buffer_pool_size"] + VAR["innodb_additional_mem_pool_size"] + VAR["innodb_log_buffer_size"]

	---
	# Commonly used screens these days easily fit more than 80 characters.
	Layout/LineLength:
	Max: 120

	# Too short methods lead to extraction of single-use methods, which can make
	# the code easier to read (by naming things), but can also clutter the class
	Metrics/MethodLength:
	Max: 20

	# Optimized my.cnf configuration for MySQL/MariaSQL
	#
	# by Fotis Evangelou, developer of Engintron (engintron.com)
	#
	# ~ Updated January 2020 ~
	#
	#
	# The settings provided below are a starting point for a 2GB - 4GB RAM server with 2-4 CPU cores.
	# If you have different resources available you should adjust accordingly to save CPU, RAM & disk I/O usage.
	#

	sudo: required
	dist: trusty

	addons:
	apt:
	sources:
	- chef-current-trusty
	packages:
	- chefdk