May 2022
Intermediate to advanced
497 pages
13h 4m
English
Content preview from SQL Server Advanced Troubleshooting and Performance Tuning
Become an O’Reilly member and get unlimited access to this title plus top books and audiobooks from O’Reilly and nearly 200 top publishers, thousands of courses curated by job role, 150+ live events each month,
O’Reilly covers everything we've got, with content to help us build a world-class technology community, upgrade the capabilities and competencies of our teams, and improve overall team performance as well as their engagement.I wanted to learn C and C++, but it didn't click for me until I picked up an O'Reilly book. When I went on the O’Reilly platform, I was astonished to find all the books there, plus live events and sandboxes so you could play around with the technology.I’ve been on the O’Reilly platform for more than eight years. I use a couple of learning platforms, but I'm on O'Reilly more than anybody else. When you're there, you start learning. I'm never disappointed.I'm always learning. So when I got on to O'Reilly, I was like a kid in a candy store. There are playlists. There are answers. There's on-demand training. It's worth its weight in gold, in terms of what it allows me to do.
Chapter 12. AlwaysOn Availability Groups
AlwaysOn Availability Groups is the most common High Availability (HA) technology used in SQL Server. It persists multiple copies of databases, eliminating storage from being the single point of failure. It also allows you to scale the read workload through multiple readable secondary nodes.
In this chapter, I’ll provide an overview of how Availability Groups work internally and explain how to troubleshoot common issues. You will learn about the overhead introduced by synchronous replicas and readable secondaries. Finally, I will discuss Availability Groups monitoring and cover how to troubleshoot failover events.
AlwaysOn Availability Groups Overview
Perhaps the easiest way to explain how AlwaysOn Availability Groups work is to look at the history of this technology. It was introduced in SQL Server 2012 as the replacement and successor to Database Mirroring, which used to have the internal Microsoft code name Real Time Log Shipping. That name is a good description: both Database Mirroring and Availability Groups rely on the stream of transaction log records to communicate. The primary node sends log records to secondaries, which harden them in their transaction logs and replay (redo) the changes in the databases.
Both technologies support the single primary node that handles the write workload. In SQL Server Enterprise Edition, Availability Groups can have multiple secondary nodes, of which some or all can handle read-only workloads. ...
Become an O’Reilly member and get unlimited access to this title plus top books and audiobooks from O’Reilly and nearly 200 top publishers, thousands of courses curated by job role, 150+ live events each month,
and much more.
Read now
Unlock full access
More than 5,000 organizations count on O’Reilly
O’Reilly covers everything we've got, with content to help us build a world-class technology community, upgrade the capabilities and competencies of our teams, and improve overall team performance as well as their engagement.Julian F.
I wanted to learn C and C++, but it didn't click for me until I picked up an O'Reilly book. When I went on the O’Reilly platform, I was astonished to find all the books there, plus live events and sandboxes so you could play around with the technology.Addison B.
I’ve been on the O’Reilly platform for more than eight years. I use a couple of learning platforms, but I'm on O'Reilly more than anybody else. When you're there, you start learning. I'm never disappointed.Amir M.
I'm always learning. So when I got on to O'Reilly, I was like a kid in a candy store. There are playlists. There are answers. There's on-demand training. It's worth its weight in gold, in terms of what it allows me to do.