Chapter 8:​ Availability for Azure SQL

Ensuring your applications are available can be critical in the modern world. This chapter looks at various High Availability (HA) and Disaster Recovery (DR) features provided by Azure SQL. 

Firstly, there’s a general discussion about HA/DR capabilities, highlighting automatic backups, point-in-time recovery, built-in HA, and Azure redundancy. All these features mean there’s much less infrastructure management for a company to undertake, leaving it to concentrate more on the applications themselves.

Next, backup and restore are examined in more detail, again highlighting automatic backups. Long-term retention backups are discussed, giving the option for longer holding periods. Azure allows the storing backups in a different geo-location, proving protection for any data center outages. 

High Availability is further discussed in relation to the various service tiers, namely: General Purpose, Business Critical, and Hyperscale (hopefully these names indicate their underlying functionality). 

The chapter ends with a look at various means of monitoring availability, covering database availability, backup and restore history, service availability, and replica status. There’s a useful section on failover reasons, and how you might want to look at using System Center Management Pack for Azure SQL.

A very useful chapter, showing that Azure provides many HA/DR features natively, although you can choose additional options for extra protection. 

Chapter 9:​ Completing Your Knowledge of Azure SQL

Having looked at deployment, configuration, security, performance, and High Availability, this chapter aims to round out your Azure SQL knowledge with a miscellany of topics.

The chapter opens with a look at features that extend Azure SQL, including: linked-severs, database mail, full-text search, and machine learning services. This is followed with a very useful look at missing features.

There’s a brief look at SQL Agent (for Managed instance), and the SQL Database equivalent (Elastic jobs) – including a helpful step-by-step walkthrough.

Despite our best efforts, errors can still occur. With this in mind, there’s a section on Azure support, covering: handling errors, stack dumps, and troubleshooting using the Azure Portal. Finally, UserVoice can be used to contact Microsoft to provide input/feedback on Azure matters. 

Best practices appear with time and usage. Luckily, others have gained experience, so you’re able to take advantage of their best practices. There are links for Best Practice documents for both Security and Performance. Lastly, there’s a useful reminder that Azure Advisor is a great place to look for recommendations for your Azure SQL, it offers recommendations for: cost, security, reliability, and performance.

This chapter was a very enjoyable read, offering plenty of advice on expanding the reach of Azure SQL, job management, support, and how to improve your systems.

Chapter 10:​ Go Big with the Cloud

Here the author aims to integrate Azure SQL into the wider world of Azure. It opens with a look at integration with 3 Azure services, namely:  

• Power Platform (Power BI, Power Apps, Power Automate)

• Azure Search (with an example integrated into SQL Database)

• Stream Analytics (real-time processing of input) 

There are of course many other services you can take advantage of, but this section gives a taster with some useful examples and walkthroughs.

Next, the chapter provides a brief look at Azure Architectures and Solutions that give you a head start in creating your own systems. An Azure Internet of Things (IoT) reference architecture is examined (very briefly).

Azure synapse is briefly discussed. It was formerly called Azure SQL Data warehouse – why must Microsoft keep changing the names of their products, it gets very frustrating!

This brief chapter provides a useful look at how Azure SQL can integrate into the wider Azure services environment.

Conclusion

This book is easy to read, having clear explanations and a good flow within and between chapters. It has helpful diagrams, and useful practical walkthroughs. A degree of humour is given that assists the reading. 

It contains useful website links for further information, in fact, the book could easily be 20-50 times bigger if you read all the links.

The author acknowledges that sometimes, the images/instructions in the book may not match those in Azure itself (the product gets updated regularly). 

Helpfully, where possible the author explains features in terms of any corresponding on-premise SQL Server features i.e. the audience is assumed to be SQL Server DBAs that want to know about the various types of SQL Server on Azure. 

Reading this book, with the author’s clear and knowledgeable explanations, made me want to read the author’s companions book (SQL Server 2019 Revealed).

Although there is overlap between Azure SQL Managed Instance and Azure SQL Database, I suspect readers will have one or the other (or deal with one at a time), so having most chapters where they are discussed together, means having to selectively pick through the chapters… It might have been better to have a distinct chapter for each (in a similar manner to having the separate chapter on Azure SQL VM) - However, this would lead to more duplication.

This book is ideal for SQL Server DBA veterans that want to make the transition to the SQL Server Azure environment. 

Overall, this is the best book I’ve read on using SQL Server with Azure.

For other recommendations of books on cloud computing see Cloud Computing Books Pick Of The Bunch