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Category: Administration

The Raw Facts on Azure SQL DB Serverless

Published 2020-10-21 by Kevin Feasel

Taiob Ali gives us a briefing summary on Azure SQL Database Serverless:

Occasionally, load balancing automatically occurs if the machine cannot satisfy resource demand within a few minutes. For example, if the resource demand is 4 vCores, but only 2 vCores are available, it may take up to a few minutes to load balance before 4 vCores are provided. The database remains online during load balancing except for a brief period at the end of the operation when connections are dropped.

Click through for more points along these lines.

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Resolving Call Stack Symbols on SQL Server 2019

Published 2020-10-20 by Kevin Feasel

Paul Randal takes us through a change to SQL Server 2019:

After beating my head against the proverbial wall for an hour, I wondered if I had the wrong symbols somehow. I checked with the excellent SQLCallStackResolver tool from GitHub (authored by Arvind Shyamsundar from the Product Group) and that worked fine with the symbols I had, so it had to be something within SQL Server.

Read on to see the answer.

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Swart’s Ten Percent Rule: User Connections

Published 2020-10-19 by Kevin Feasel

Michael J. Swart applies Swart’s 10% Rule to maximum simultaneous user connections:

The maximum number of user connections that SQL Server can support is 32,767. That’s it. That’s the end of the line. You can buy faster I.O. or a server with more CPUs but you can’t buy more connections.

I actually mentioned this limit in the post where I introduced Swart’s 10% rule: “If you’re using over 10% of what SQL Server restricts you to, you’re doing it wrong” In that post, I was guarded about that statement as it applied to the user connection limit. But I’d like to upgrade that to elevated.

This is Threat Level Vermillion, people!

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Use T-SQL to Check the SQL Agent Status

Published 2020-10-14 by Kevin Feasel

Jack Vamvas shows how you can check on the SQL Server Agent status using T-SQL:

I want to check if SQL Server Agent is running using t-sql.    I know I can check through the services.msc or other methods such as Powershell scripts to report on the SQL Server Agent status , but the requirement is to extract this information via t-sql. Do you have a script using t-sql to get the SQL Server Agent Status?

There is a method and Jack shows us the way.

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Copying an Azure SQL Database

Published 2020-10-14 by Kevin Feasel

Garry Bargsley gives us two methods for copying an Azure SQL Database:

Copying an Azure SQL Database is a vital skill when managing cloud databases. Recently, a request was received from the “business”. They wanted to create a copy of an Azure SQL Database that was in a development environment. The database has been certified and early testing was accepted. They now want an exact copy in QA to start integration testing. The process of making an Azure SQL Database copy is straightforward. There are several different ways to perform this action.

Two methods chosen will use the Azure Portal and PowerShell to demonstrate the completion of this request.

Click through for the demos.

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Diagnosing and Solving tempdb Bottlenecks

Published 2020-10-13 by Kevin Feasel

Ameena Lalani shares some good info on the tempdb database:

Tempdb is a SQL Server temporary system database. Everytime SQL Server restarts, new Tempdb database is created. Whatever data was stored in the tempdb is lost. When TempDB gets recreated its data and log files reset to their last configured size. SQL Server records only enough information in the tempdb transaction log to roll back a transaction, but not to redo transactions during database recovery. This feature increases the performance of INSERT statements in tempdb. Tempdb database is always in Simple recovery mode. If you try to change it to Full Recovery mode, you will receive the following error message.

Click through for more info on how the database is special, types of issues you can run into as concurrency grows, and ways to resolve those issues.

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Using sp_PressureDetector to Find Resource Constraints

Published 2020-10-13 by Kevin Feasel

Erik Darling has started a new series:

If you go to open a new tab in SSMS and you hear a creaking sound, it might be time to revisit some of your hardware choices.

But that’s a problem for future you. Your problem is right now.

– How to check it: sp_PressureDetector
– What to look for: Stuck queries, Resource Usage, Wait Stats

By default, it’ll look at both CPU and Memory counters. If you don’t know what’s going on, just hit F5.

Read on to see what it looks like for a server hitting memory limits and for a server hitting CPU limits.

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Tips for Monitoring Kubernetes

Published 2020-10-09 by Kevin Feasel

Michael Sorens walks us through some tips for monitoring Kubernetes:

The world begins, of course, with kubectl, the command-line interface to Kubernetes. The commands you start using early on help you examine your Kubernetes resources.

kubectl get . . .

With that command, you can examine your deployments, which rollout your replica sets, which create pods. Then you need services, which are logical sets of pods that provide an interface for external access. What can you examine with kubectl get ?

Use kubectl api-resources to see the list. At the time of this writing, there are 66 different resource types! That number will likely only grow over time. 

Read on for more, including the setup of the Kubernetes UI and third-party tooling.

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Oracle Error ORA-28353: Failed to Open Wallet

Published 2020-10-09 by Kevin Feasel

Rene Antunez diagnoses an Oracle error:

I noticed the original error after applying the October 2018 bundle patch (BP) for 11.2.0.4. While I realize most clients are no longer in 11.2.0.4, this information remains valid for anyone upgrading from 11.2 to 12, 18 or 19c.

I had been doing several tests on my Spanish RAC (Real Application Cluster) Attack for 12.2. The goal was to patch my client to October 2018 PSU; obtaining enough security leverage to avoid patching their database and do their DB (database) upgrade to 18c. I created RAC VMs to enable testing. I also set up my environment to match the client’s, which had TDE with FIPS 140 enabled (I will provide more details on this later in the post).

While the patching was successful, the problem arose after applying the patch. I was unable to open the database despite having the correct password for the encryption key.

When I first read the title, I thought it was a joke making fun of Oracle’s licensing practices.

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Database Mail on Azure SQL Managed Instances

Published 2020-10-07 by Kevin Feasel

John McCormack shows how you can set up database mail from an Azure SQL Managed Instance:

It’s not too difficult to set up database mail for Azure SQL DB Managed Instance in comparison to SQL Server (on-prem or IaaS) however there are a few extra things to consider. This post will describe how to set up database mail for Azure SQL DB Managed Instance. I will use Sendgrid as the mail provider but you can follow the same steps for any other mail provider or your company’s smtp server.

Before I go on, my personal opinion is that including database mail is a massive feature for Managed Instances. The lack of DB Mail on Azure SQL DB Single Database or Amazon RDS is a major blocker to PaaS adoption. Now with Managed Instance, we can have PaaS and database mail.

Read on for the instructions. There’s a little bit more than what you typically would need to do on-premises, but just a little bit.

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