Mehdi Hasan Khan mugli

Multiple MySQL Versions with Homebrew

For homebrew version 0.9.5.

brew -v # => Homebrew 0.9.5

Install the current version of mysql.

# Install current mysql version

brew install mysql

Using closure tables to manage hierarchical relations in MySQL

Create DB tables

Create a table to represent tree nodes.

CREATE TABLE `tree_node` (
    `id` int(10) unsigned NOT NULL AUTO_INCREMENT,
    `data_body` text,

node_deleted datetime DEFAULT NULL,

anordal/shellharden https://github.com/anordal/shellharden/blob/master/how_to_do_things_safely_in_bash.md
Ten More Things I Wish I’d Known About bash https://zwischenzugs.com/2018/01/21/ten-more-things-i-wish-id-known-about-bash
Ten Things I Wish I’d Known About bash https://zwischenzugs.com/2018/01/06/ten-things-i-wish-id-known-about-bash
When Bash Scripts Bite :: Jane Street Tech Blogs https://blogs.janestreet.com/when-bash-scripts-bite/
Gensokyo Blog - Use Bash Builtins shell,fish,bash https://blog.gensokyo.io/a/fafbe742.html
Defensive Bash Programming http://www.kfirlavi.com/blog/2012/11/14/defensive-bash-programming/
barryclark/bashstrap https://github.com/barryclark/bashstrap
Detecting the use of "curl | bash" server side

Best Practices for Azure Redis

Below are a set of best practices that I recommend for most customers. This information is based on my experience helping hundreds of Azure Redis customers investigate various issues.

Configuration and Concepts

Use Standard or Premium Tier for Production systems. The Basic Tier is a single node system with no data replication and no SLA. Also, use at least a C1 cache. C0 caches are really meant for simple dev/test scenarios since they have a shared CPU core, very little memory, are prone to "noisy neighbor", etc.
Remember that Redis is an In-Memory data store. Read this article so that you are aware of scenarios where data loss can occur.
Configure your client library to use a "connect timeout" of at least 10 to 15 seconds, giving the system time to connect even under higher CPU conditions. If your client or server tend to be under high load

What do Etcd, Consul, and Zookeeper do?
- Service Registration:
  - Host, port number, and sometimes authentication credentials, protocols, versions numbers, and/or environment details.
- Service Discovery:
  - Ability for client application to query the central registry to learn of service location.
- Consistent and durable general-purpose K/V store across distributed system.
  - Some solutions support this better than others.
  - Based on Paxos or some derivative (i.e. Raft) algorithm to quickly converge to a consistent state.
Centralized locking can be based on this K/V store.

Kafka Cheat Sheet

Display Topic Information

$ kafka-topics.sh --describe --zookeeper localhost:2181 --topic beacon
Topic:beacon	PartitionCount:6	ReplicationFactor:1	Configs:
	Topic: beacon	Partition: 0	Leader: 1	Replicas: 1	Isr: 1
	Topic: beacon	Partition: 1	Leader: 1	Replicas: 1	Isr: 1

	/**
	* MIT License

	Copyright (c) 2018 Matthew D. Bark

	Permission is hereby granted, free of charge, to any person obtaining a copy
	of this software and associated documentation files (the "Software"), to deal
	in the Software without restriction, including without limitation the rights
	to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
	copies of the Software, and to permit persons to whom the Software is

	DO WHAT THE FUCK YOU WANT TO PUBLIC LICENSE
	Version 2, December 2004

	Copyright (C) 2011 Jed Schmidt <http://jed.is>

	Everyone is permitted to copy and distribute verbatim or modified
	copies of this license document, and changing it is allowed as long
	as the name is changed.

	DO WHAT THE FUCK YOU WANT TO PUBLIC LICENSE

	db.currentOp().inprog.forEach(
	function(op) {
	if(op.secs_running > 5) printjson(op);
	}
	)