Press "Enter" to skip to content

Category: Cloud

Azure Shared Disk with Zone-Redundant Storage

Published 2022-05-12 by Kevin Feasel

Dave Bermingham runs some tests:

What makes this interesting is that you can now build shared storage based failover cluster instances that span Availability Zones (AZ).  With cluster nodes residing in different AZs, users can now qualify for the 99.99% availability SLA. Prior to support for ZRS, Azure Shared Disks only supported Locally Redundant Storage (LRS), limiting cluster deployments to a single AZ, leaving users susceptible to outages should an AZ go offline.

There are however a few limitations to be aware of when deploying an Azure Shared Disk with ZRS.

Dave also checks to see how their performance compares to locally-redundant storage.

Comments closed

Partial Update Operations in Cosmos DB

Published 2022-05-10 by Kevin Feasel

Hasan Savran partially deflates the partial update bubble:

Partial Update was one of the most wanted features by Cosmos DB customers. In a regular update operation, you need to send the whole JSON document to Cosmos DB. This can be silly if your data model is large and you want to update one field in it. With a regular update, your request object will be large because you need to send the whole data model. Regular Update operation needs more resources from the client/SDK and network bandwidth.

    You might think that partial updates might cost fewer request units. Unfortunately, this is not the case. Because Cosmos DB still needs to open the JSON document, change the necessary properties and save the data. Cosmos DB uses almost the same amount of CPU and memory for this operation for a regular update or a partial update.

That it costs just about as much as a full write does reduce the value of partial updates. Still, there is some value in reducing bandwidth requirements or making changes where you don’t know the entire contents of the document up-front.

Comments closed

Azure Redis Cache Geo-Replication

Published 2022-05-09 by Kevin Feasel

Arun Sirpal shows how to set up geo-replication in Azure Redis Cache:

The concept of a geo-replicated partnership between a primary and secondary node is very similar to that of something you may have seen with Azure SQL DB, where the primary handles all R/W and then the changes are pushed to secondary ( async). This is no different with Redis.

Read on to see what limitations exist and how you can set up geo-replication.

Comments closed

Azure SQL DB ARM Template Conflicts with Azure AD Administration

Published 2022-05-06 by Kevin Feasel

Joao Antunes points out a potential timing issue around combining Azure Active Directory administration with Azure SQL Database ARM templates:

ARM templates are widely used when we need to repeatedly deploy solutions/infrastructures in the cloud. Leveraging the concept of infrastructure as code ARM templates are a powerful resource to ease our daily job, however we might face some challenges when using them.

When we are creating several resources within the same template – using Json or Bicep – it’s crucial to make sure that all resources are created in the right order, ensuring that all depending on resources are fully provisioned before you move to the next operation.

Error (internal server errors) and conflicts  can occur during our ARM template deployment and it could be difficult to troubleshoot or understand the root cause of them.

Read on for one annoying error and its fix.

Comments closed

Data Products in Data Mesh

Published 2022-05-06 by Kevin Feasel

Paul Andrew takes us through a thought process:

In the context of an idealistic data mesh architecture, establishing a working definition of a data product seems to be very real problem for most. What constitutes a data product seems to be very subjective, circumstantial in terms requirements and interlaced with platform technical maturity. AKA, a ‘minefield’ to navigate in definitional terms.

To help get my thoughts in order (as always) here is my currently thinking and definition for a data mesh – data product.

Read on for Paul’s thoughts.

Comments closed

Finding Azure SQL DB Backup History

Published 2022-05-05 by Kevin Feasel

Taiob Ali takes us through a new DMV:

There is a new DMV currently in preview which returns information about backups of Azure SQL databases except for the Hyperscale tier. Microsoft official documentation is here.

If you run the example query as-is from the above documentation some of the columns do not make sense.

Taiob includes a better query which provides the type of information you’re used to in on-premises SQL Server.

Comments closed

Comparing Databricks to Synapse Spark Pools

Published 2022-05-04 by Kevin Feasel

Corrinna Peters makes comparisons:

There are different cases for using both depending on the specific needs and requirements, Synapse and Databricks are similar, but both have their own areas of specialities or rather areas where they are above the other.

Data Lake – they both allow you to query the data from the data lake, Synapse uses either the SQL on demand pool or Spark and Databricks uses the Databricks workspace once you have mounted the data lake. If you are predominately a SQL user and prefer the code and the BI developer feel then Synapse would be the correct choice whereas if you are a Data Scientist and prefer to code in Python or R then Databricks would feel more at home.

Read on for a nuanced take. My less nuanced take is, Databricks beats the pants off of Synapse Spark pools in terms of performance. Synapse has a much better overall ecosystem, expanding beyond Spark and into T-SQL (in two flavors) and log/event analytics with KQL. If you’re spending 100% of your time in Spark and don’t care about the rest, use Databricks; if Spark is a relatively small part of your warehousing work, use Synapse.

1 Comment

Transparent Data Encryption in RDS

Published 2022-05-04 by Kevin Feasel

Tom Collins enables Transparent Data Encryption in AWS’s RDS:

Does AWS RDS SQL Server support built-in SQL Server Transparent Data Encryption (TDE)?  Yes , is the short answer , but there are some limitations  . 

Before I dive into the AWS SQL Server RDS TDW limitations , in this post  we’re discussing SQL Server TDE as opposed to RDS Encryption covering Aurora, MySQL, MariaDB, PostgreSQL, Oracle, SQL Server

Read on for the limitations Tom mentions.

Comments closed

Using Extended Events with AWS RDS

Published 2022-05-03 by Kevin Feasel

Grant Fritchey tries out extended events in Amazon’s RDS:

AWS has posted the documentation on what you have to do in order to enable the collection of Extended Events within RDS. Normallly, I’d follow along with the documentation. However, I’m going to approach this like I knew that Extended Events support was there, but I wasn’t aware of the docs. So, I’m starting in SSMS and I’m just going to try plugging in the Extended Events GUI to see what happens. Further, I’m going to use the simplest method for launching Extended Events, XEvent Profiler. 

Read on for Grant’s findings.

Comments closed