Centos High Availability

This book is targeted at system engineers and system administrators who want to upgrade their knowledge and skills in high availability and want to learn practically how to achieve high availability with CentOS Linux. You are expected to have good CentOS Linux knowledge and basic networking experience.

This IBM® Redpaper publication delivers an updated guide for high availability and disaster recovery (HADR) planning in a multicloud environment for IBM Power. This publication describes the ideas from studies that were performed in a virtual collaborative team of IBM Business Partners, technical focal points, and product managers who used hands-on experience to implement case studies to show HADR management aspects to develop this technical update guide for a hybrid multicloud environment. The goal of this book is to deliver a HADR guide for backup and data management on-premises and in a multicloud environment. This document updates HADR on-premises and in the cloud with IBM PowerHA® SystemMirror®, IBM VM Recovery Manager (VMRM), and other solutions that are available on IBM Power for IBM AIX®, IBM i, and Linux. This publication highlights the available offerings at the time of writing for each operating system (OS) that is supported in IBM Power, including best practices. This book addresses topics for IT architects, IT specialists, sellers, and anyone looking to implement and manage HADR on-premises and in the cloud. Moreover, this publication provides documentation to transfer how-to skills to the technical teams and solution guidance to the sales team. This book complements the documentation that is available at IBM Documentation and aligns with the educational materials that are provided by IBM Systems Technical Training.

Create high availability clusters to enhance system performance using CentOS 7 About This Book Master the concepts of high performance and high availability to eliminate performance bottlenecks Maximize the uptime of services running in a CentOS 7 cluster A step-by-step guide that will provide knowledge of methods and approaches to optimize the performance of CentOS clusters Who This Book Is For This book is targeted at system administrators: those who want a detailed, step-by-step guide to learn how to set up a high-availability CentOS 7 cluster, and those who are looking for a reference book to help them learn or refresh the necessary skills to ensure their systems and respective resources are utilized optimally. No previous knowledge of high-availability systems is needed, though the reader is expected to have at least some degree of familiarity with any spin-off of the Fedora family of Linux distributions, preferably CentOS. What You Will Learn Install a CentOS 7 cluster and network infrastructure Configure firewall, networking, and clustering services and settings Set up and test a HAC (high-availability cluster) to host an Apache web server and a MariaDB database server Monitor performance and availability Identify bottlenecks and troubleshoot issues Improve performance and ensure high availability In Detail CentOS is the enterprise level Linux OS, which is 100% binary compatible to Red Hat Enterprise Linux (RHEL). It acts as a free alternative to RedHat's commercial Linux offering, with only a change in the branding. A high performance cluster consists in a group of computers that work together as one set parallel, hence minimizing or eliminating the downtime of critical services and enhancing the performance of the application. Starting with the basic principles of clustering, you will learn the necessary steps to install a cluster with two CentOS 7 servers. We will then set up and configure the basic required network infrastructure and clustering services. Further, you will learn how to take a proactive approach to the split-brain issue by configuring the failover and fencing of the cluster as a whole and the quorum of each node individually. Further, we will be setting up HAC and HPC clusters as a web server and a database server. You will also master the art of monitoring performance and availability, identifying bottlenecks, and exploring troubleshooting techniques. At the end of the book, you'll review performance-tuning techniques for the recently installed cluster, test performance using a payload simulation, and learn the necessary skills to ensure that the systems, and the corresponding resources and services, are being utilized to their best capacity. Style and approach An easy-to-follow and step-by-step guide with hands-on instructions to set up real-world simple cluster scenarios that will start you on the path to building more complex applications on your own.

CentOS is just like Red Hat, but without the price tag and with the virtuous license. When belts have to be tightened, we want to read about an OS with all the features of a commercial Linux variety, but without the pain. The Definitive Guide to CentOS is the first definitive reference for CentOS and focuses on CentOS alone, the workhorse Linux distribution, that does the heavy lifting in small and medium-size enterprises without drawing too much attention to itself. Provides tutorial and hands-on learning but is also designed to be used as a reference Bases all examples on real-world tasks that readers are likely to perform Serves up hard-won examples and hints and tips from the author's experiences of CentOS in production

A concise walk-through of CentOS 7, starting from installation to securing it’s environment. Key FeaturesNo previous Linux environment experience needed for reading this bookGet comfortable with a popular and stable Red Hat Enterprise Linux distributionMost of the command line based concepts are explained with graphicsBook Description Linux kernel development has been the worlds largest collaborative project to date. With this practical guide, you will learn Linux through one of its most popular and stable distributions. This book will introduce you to essential Linux skills using CentOS 7. It describes how a Linux system is organized, and will introduce you to key command-line concepts you can practice on your own. It will guide you in performing basic system administration tasks and day-to-day operations in a Linux environment. You will learn core system administration skills for managing a system running CentOS 7 or a similar operating system, such as RHEL 7, Scientific Linux, and Oracle Linux. You will be able to perform installation, establish network connectivity and user and process management, modify file permissions, manage text files using the command line, and implement basic security administration after covering this book. By the end of this book, you will have a solid understanding of working with Linux using the command line. What you will learnUnderstand file system hierarchy and essential command-line skillsUse Vi editor, I/O redirections and how to work with common text manipulating toolsCreate, delete, modify user accounts and manage passwords and their aging policyManage file ownership, permissions, and ACLExecute process management and monitoring on the command lineValidate and manage network configuration using nmcliManage remote logins using SSH and file transfer using SCP and RsyncUnderstand system logging, how to control system services with systemd and systemctl, and manage firewalIdWho this book is for Any individual who wants to learn how to use Linux as server or desktop in his environment. Whether you are a developer, budding system administrator, or tech lover with no previous Linux administration background, you will be able to start your journey in Linux using CentOS 7 with this book.

Pro Linux High Availability Clustering teaches you how to implement this fundamental Linux add-on into your business. Linux High Availability Clustering is needed to ensure the availability of mission critical resources. The technique is applied more and more in corporate datacenters around the world. While lots of documentation about the subject is available on the internet, it isn't always easy to build a real solution based on that scattered information, which is often oriented towards specific tasks only. Pro Linux High Availability Clustering explains essential high-availability clustering components on all Linux platforms, giving you the insight to build solutions for any specific case needed. In this book four common cases will be explained: Configuring Apache for high availability Creating an Open Source SAN based on DRBD, iSCSI and HA clustering Setting up a load-balanced web server cluster with a back-end, highly-available database Setting up a KVM virtualization platform with high-availability protection for a virtual machine. With the knowledge you'll gain from these real-world applications, you'll be able to efficiently apply Linux HA to your work situation with confidence. Author Sander Van Vugt teaches Linux high-availability clustering on training courses, uses it in his everyday work, and now brings this knowledge to you in one place, with clear examples and cases. Make the best start with HA clustering with Pro Linux High Availability Clustering at your side.

A comprehensive guide to understanding key techniques for architecture and hardware planning, monitoring, replication, backups, and decoupling Key FeaturesNewly updated edition, covering the latest PostgreSQL 12 features with hands-on industry-driven recipesCreate a PostgreSQL cluster that stays online even when disaster strikesLearn how to avoid costly downtime and data loss that can ruin your businessBook Description Databases are nothing without the data they store. In the event of an outage or technical catastrophe, immediate recovery is essential. This updated edition ensures that you will learn the important concepts related to node architecture design, as well as techniques such as using repmgr for failover automation. From cluster layout and hardware selection to software stacks and horizontal scalability, this PostgreSQL cookbook will help you build a PostgreSQL cluster that will survive crashes, resist data corruption, and grow smoothly with customer demand. You’ll start by understanding how to plan a PostgreSQL database architecture that is resistant to outages and scalable, as it is the scaffolding on which everything rests. With the bedrock established, you'll cover the topics that PostgreSQL database administrators need to know to manage a highly available cluster. This includes configuration, troubleshooting, monitoring and alerting, backups through proxies, failover automation, and other considerations that are essential for a healthy PostgreSQL cluster. Later, you’ll learn to use multi-master replication to maximize server availability. Later chapters will guide you through managing major version upgrades without downtime. By the end of this book, you’ll have learned how to build an efficient and adaptive PostgreSQL 12 database cluster. What you will learnUnderstand how to protect data with PostgreSQL replication toolsFocus on hardware planning to ensure that your database runs efficientlyReduce database resource contention with connection poolingMonitor and visualize cluster activity with Nagios and the TIG (Telegraf, InfluxDB, Grafana) stack Construct a robust software stack that can detect and avert outagesUse multi-master to achieve an enduring PostgreSQL clusterWho this book is for This book is for Postgres administrators and developers who are looking to build and maintain a highly reliable PostgreSQL cluster. Although knowledge of the new features of PostgreSQL 12 is not required, a basic understanding of PostgreSQL administration is expected.

Over 80 recipes to get up and running with CentOS 7 Linux server About This Book A practical guide to install, configure, administer and maintain CentOS 7 servers An in-depth guide to the CentOS 7 operating system, exploring its various new features and changes in server administration Presents tricks and solutions to tackle common server issues with the help of practical examples and real-life scenarios Who This Book Is For This book is targeted at beginner and more experienced system administrators alike who want to use CentOS as their server solution. Readers do not need much pre-knowledge or experience at all to work with this book. What You Will Learn Install and configure CentOS 7 Linux server system from scratch using normal and advanced methods Maintain a performance-based and secure server solution by deploying expert configuration advice and managing software packages Monitor, manage and develop your server's file system to maintain a stable performance Gain best practice methods on sharing files and resources through a network Install and configure common standard services such as web, mail, FTP, database and domain name server technologies Introduce you to the world of operating-system-level virtualization using the Docker platform. Understand the fundamentals of the Security-Enhanced Linux access control architecture Monitor your IT infrastructure using Nagios In Detail This book will provide you with a comprehensive series of starting points that will give you direct access to the inner workings of the latest CentOS version 7 and help you trim the learning curve to master your server. You will begin with the installation and basic configuration of CentOS 7, followed by learning how to manage your system, services and software packages. You will then gain an understanding of how to administer the file system, secure access to your server and configure various resource sharing services such as file, printer and DHCP servers across your network. Further on, we cover advanced topics such as FTP services, building your own DNS server, running database servers, and providing mail and web services. Finally, you will get a deep understanding of SELinux and you will learn how to work with Docker operating-system virtualization and how to monitor your IT infrastructure with Nagios. By the end of this book, you will have a fair understanding of all the aspects of configuring, implementing and administering CentOS 7 Linux server and how to put it in control. Style and approach This book is a practical reference guide with hands-on examples and solutions to real-world administration problems. It covers in-depth and comprehensive information on CentOS 7 and its new features.