Book excerpt: Over 100 recipes to design and implement a highly available server with the advanced features of PostgreSQL 9.4,9.5 and 9.6About This Book* Create a PostgreSQL cluster that stays online even when disaster strikes* Avoid costly downtime and data loss that can ruin your business* Updated to include the newest features introduced in PostgreSQL 9.6 with hands-on industry-driven recipesWho This Book Is ForIf you are a PostgreSQL DBA working on Linux systems who want a database that never gives up, this book is for you. If you've ever experienced a database outage, restored from a backup, spent hours trying to repair a malfunctioning cluster, or simply want to guarantee system stability, this book is definitely for you.What you will learn* Protect your data with PostgreSQL replication and management tools such as Slony, Bucardo, pglogical, and WAL-E* Hardware planning to help your database run efficiently* Prepare for catastrophes and prevent them before they happen* Reduce database resource contention with connection pooling using pgpool and PgBouncer* Automate monitoring and alerts to visualize cluster activity using Nagios and collected* Construct a robust software stack that can detect and fix outages* Learn simple PostgreSQL High Availability with Patroni, or dive into the full power of Pacemaker.In DetailDatabases are nothing without the data they store. In the event of a failure - catastrophic or otherwise - immediate recovery is essential. By carefully combining multiple servers, it's even possible to hide the fact a failure occurred at all.From hardware selection to software stacks and horizontal scalability, this book will help you build a versatile PostgreSQL cluster that will survive crashes, resist data corruption, and grow smoothly with customer demand. It all begins with hardware selection for the skeleton of an efficient PostgreSQL database cluster. Then it's on to preventing downtime as well as troubleshooting some real life problems that administrators commonly face. Next, we add database monitoring to the stack, using collectd, Nagios, and Graphite. And no stack is complete without replication using multiple internal and external tools, including the newly released pglogical extension. Pacemaker or Raft consensus tools are the final piece to grant the cluster the ability to heal itself. We even round off by tackling the complex problem of data scalability.This book exploits many new features introduced in PostgreSQL 9.6 to make the database more efficient and adaptive, and most importantly, keep it running.