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Showing posts from February, 2018

Python Script for Generating Random Passwords

This Python script is practical for generating random passwords.

A password contains:
7 lowercase alphabetic characters.
2 uppercase alphabetic characters.
2 numeric characters.
1 special character. (special char will be one of these: ! + % ? * - _ )

3 Node (Master Slave Slave) Redis Cluster with Sentinel

It is possible to make your Redis cluster Fault Tolerant and Highly Available by building a replica set and then monitor these nodes using sentinel for automatic failover.
I am going to give an example setup to explain it. The structure is built with three nodes running one as a master and two as slaves.
Master Node: (Centos 7.2) 192.168.1.11 Slave1 Node: (Centos 7.2) 192.168.1.12 Slave2 Node: (Centos 7.2) 192.168.1.13
Edit System settings on each node: /etc/sysctl.conf
Disable transparent hugepage (transparent_hugepage=never) on each node: /etc/default/grub
Apply grub config and reboot each node:
Master Node: /etc/redis/6379.conf
Slave1 Node: /etc/redis/6379.conf
Slave2 Node: /etc/redis/6379.conf
Master Node: /etc/redis/sentinel.conf
Slave1 Node: /etc/redis/sentinel.conf
Slave2 Node: /etc/redis/sentinel.conf
Each Node: /etc/systemd/system/multi-user.target.wants/redis-server.service
Each Node: /etc/systemd/system/multi-user.target.wants/redis-sentinel.service
After creating service files reload sy…