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Category: Cloud

Calculating Cloud App Availability

Published 2020-07-27 by Kevin Feasel

Dave Bermingham gives you a way to calculate how available you should expect your application to be given SLAs:

When deploying business critical applications in the cloud you want to make sure they are highly available. The good news is that if you plan properly, you can achieve 99.99% (4-nines) of availability or more. However, calculating your true availability may not be as straightforward as it seems.

When considering availability you must consider the key components that make access to your application possible, which I’ll call the availability chain. Component of the availability chain are:

– Compute
– Network 
– Storage
– Application
– Dependent services

Your application is only as available as your weakest link, and your downtime increases exponentially with each additional link you add to the chain.  Let’s examine each of the links. 

Read on for a breakdown of these items.

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Understanding Digital Twins in IoT Hub

Published 2020-07-24 by Kevin Feasel

Paul Hernandez explains the concept of digital twins in the IoT space:

Azure Digital Twins Service offers a way to build next generation IoT solutions. There are other approaches on the market to describe IoT devices and build digital twins. Without making a formal comparison I can say with the Azure Digital Twins is possible to build a powerful semantic layer on top of your connected devices using domain specific models.

To show you how this work let’s create a kind of “hello world” example. An end-to-end solution is out-of-scope of this post. Instead I will create some hands-on tutorial to demonstrate some of the functionalities.

Click through to see an example.

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Assuming a Role with AWS Powershell Tools

Published 2020-07-23 by Kevin Feasel

Sheldon Hull solves a problem:

I’ve had some issues in the past working with AWS.Tools PowerShell SDK and correctly assuming credentials.

By default, most of the time it was easier to use a dedicated IAM credential setup for the purpose.

However, as I’ve wanted to run some scripts across multiple accounts, the need to simplify by assuming a role has been more important.

It’s also a better practice than having to manage multiple key rotations in all accounts.

Read on to see how far Sheldon has been able to take this, but also how much more work is left to do.

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Disk Caching with SQL Server VM Disks in Azure

Published 2020-07-22 by Kevin Feasel

Niko Neugebauer performs some tests:

Microsoft has been extremely clear in the best practices recommendation for the SQL Server workloads on Azure VMs:
– use read caching for the data drives/storage pools
– use no caching for the log drives/storage pools
– use read caching for the temp db drives/storage pools

Sounds simple and direct, isn’t it ?
Let me borrow your attention for the next couple of minutes pointing to some situations where you might want to reconsider the best practices.

But do read on for some important notes.

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Auto-Shutdown an Azure VM and Notify You on Slack

Published 2020-07-21 by Kevin Feasel

Daniel Hutmacher has a fun assignment:

Virtual machines cost money when they’re powered on. Most servers obviously need to be on 24 hours a day. Others, like development machines, only have to be on when you’re using them. And if you forget to turn them off, they’ll empty out your Azure credits (or your credit card) before you know it.

Today, I’ll show you how to set an Auto-shutdown time to turn a VM off if you forget, as well as have Azure notify you on Slack 30 minutes ahead of time, so you have the option to postpone or cancel the shutdown.

There are a few steps to the process, but everything is straightforward.

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Azure SQL Database Business Continuity Options

Published 2020-07-21 by Kevin Feasel

James Serra covers business continuity scenarios with Azure SQL Database:

I have wrote a number of blogs on the topic of business continuity in SQL Database before (HA/DR for Azure SQL Database, Azure SQL Database high availability, Azure SQL Database disaster recovery) but with a number of new features I felt it was time for a new blog on the subject, focusing on disaster recovery and not high availability.

Business continuity in Azure SQL Database and SQL Managed Instance refers to the mechanisms, policies, and procedures that enable your business to continue operating in the face of disruption, particularly to its computing infrastructure. In the most of the cases, SQL Database and SQL Managed Instance will handle the disruptive events that might happen in the cloud environment and keep your applications and business processes running.

James takes us through options available for Azure SQL Database as well as managed instances.

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Azure Data Factory and Key Vault References

Published 2020-07-20 by Kevin Feasel

Gerhard Brueckl shows how we can get around a limitation in the Azure Data Factory user interface:

As You can see, the setting “AccessToken” can use a Key Vault reference whereas settings like “Databricks Workspace URL” and “Cluster” do not support them. This is usually fine because the guys at Microsoft also thought about this and support Key Vault references for the settings that are actually security relevant or sensitive. Also, providing the option to use Key Vault references everywhere would flood the GUI. So this is just fine.

But there can be good reasons where you want to get values from the Key Vault also for non-sensitive settings, especially when it comes to CI/CD and multiple environments. From my experience, when you implement a bigger ADF project, you will probably have a Key Vault for your sensitive settings and all other values are provided during the deployment via ARM parameters.

So you will end up with a mix of Key Vault references and ARM template parameters which very likely will be derived from the Key Vault at some point anyway. To solve this, you can modify the JSON of an ADF linked service directly and inject KeyVault references into almost every property!

Click through to see how that works, as well as the ramifications.

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Comparing Integration Services and Azure Data Factory

Published 2020-07-17 by Kevin Feasel

Tim Mitchell compares SQL Server Integration Services to Azure Data Factory:

For the better part of 15 years, SQL Server Integration Services (SSIS) has been the go-to enterprise extract-transform-load (ETL) tool for shops running on Microsoft SQL Server. More recently, Microsoft added Azure Data Factory (ADF) to its stable of enterprise ETL tools. In this post, I’ll be comparing SSIS and Azure Data Factory to share how they are alike and how they differ. I’ll also review the strengths and shortcomings of each, including the architectures in which each of these is likely to do well.

Read on for Tim’s thoughts on the subject. Tim lays out his biases up-front but also gives you a good feel for where both products are in their lifecycles.

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Case-Insensitive Searches in Cosmos DB

Published 2020-07-17 by Kevin Feasel

Hasan Savran gives us a few techniques for case-insensitive searching in Azure Cosmos DB:

Data gets saved as JSON in Azure Cosmos DB. JSON documents supports string, numeric and Boolean data types. Because of limited data types, you might end up picking string data type for most of your data. You may need to use Cosmos DB’s string functions to help you in many situations. For example; you might need to find names start with bunch of characters or you might need to find data ends like a word or bunch of characters. You may need to find all data that has address contains a street name. What do you do in these cases? Azure Cosmos DB has couple of system functions to help you, I will focus on the following functions in this post. These are the functions just got updated in June 2020.

Click through to learn a bit about those money-saving updates.

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Getting Started with Redshift

Published 2020-07-17 by Kevin Feasel

Rahul Mehta has a primer on AWS Redshift:

AWS Redshift is a columnar data warehouse service on AWS cloud that can scale to petabytes of storage, and the infrastructure for hosting this warehouse is fully managed by AWS cloud. Redshift operates in a clustered model with a leader node, and multiple worked nodes, like any other clustered or distributed database models in general. It is based on Postgres, so it shares a lot of similarities with Postgres, including the query language, which is near identical to Structured Query Language (SQL). This Redshift supports creating almost all the major database objects like Databases, Tables, Views, and even Stored Procedures. In this article, we will explore how to create your first Redshift cluster on AWS and start operating it.

I’m not really the biggest fan of Redshift around, but Rahul does a good job walking us through the basics of the product.

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