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Category: Administration

Troubleshooting High Non-SQL CPU Utilization

Published 2022-10-03 by Kevin Feasel

Ajay Dwivedi finds out it wasn’t the database:

Since SQL Server is not a cheap application and would cost a lot of money if we need to scale it horizontally. So it is not a good practice to allow any other resource-consuming processes to run alongside with SQL Server.

In this blog, we are going to troubleshoot a high CPU scenario when the CPU issue is caused by non-SQL Server process. Let’s say, I receive a call from the monitoring team where the application team is complaining about a “slow” SQL Server.

Ajay first uses SQLMonitor to perform this troubleshooting and then shows how to do this without SQLMonitor.

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High Memory Grants in SQL Server

Published 2022-09-30 by Kevin Feasel

Ajay Dwivedi tracks down memory grants:

Very often, specially on mixed workload enviroment where server deals with oltp & olap queries together, concurrent sessions allocated with High Memory Grants cause entire SQL Server workload to suffer.

To detect such a situation, I like to watch my critical metrics dashboards. For example, dashboard Monitoring – Live -All Servers of free SQLMonitor tool highlights all these metrics.

Click through for an example of the dashboard as well as a diagnostic query which helps find high-memory grant queries.

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Tracking Bulk Insert Usage with Extended Events

Published 2022-09-30 by Kevin Feasel

Grant Fritchey wants to see if you’re bulking up:

Wouldn’t it be great to be able to directly monitor specific behaviors within SQL Server, like, oh, I don’t know, knowing exactly when, and how, someone is using BULK INSERT? Well, you can, thanks to Extended Events through the bulk_insert_usage event.

Click through for an overview of what this event provides, as well as what it doesn’t provide.

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Triggering Dumps for Specific Errors and States

Published 2022-09-29 by Kevin Feasel

Bob Dorr has a plan:

I had an inquiry about dbcc dumptrigger today and realized that state filtering was added to dbcc dumptrigger but not well known.

You can collect a process dump (SQL Dumper) when a specific error occurs using XEvent (error_reported/ex_raise2 events with dump capture action) or dbcc dumptrigger.

The common use of dbcc dumptrigger is: dbcc dumptrigger(‘set’, 208) to produce a dump when error 208 is encountered.

This is pretty useful, especially if you’re troubleshooting a bug in the database engine.

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In-Place SQL Server Upgrades

Published 2022-09-28 by Kevin Feasel

Garry Bargsley rolls the dice:

In my experience, two options exist to get the desired result. One, create a new server, install the latest supported version of SQL Server, and migrate your data. Two, upgrade SQL Server on the existing server.

There are pros and cons to each of these options. My preference is to go with option number one as it allows you more flexibility in your migration plan. However, many smaller shops might not have the hardware resources for this option, so they are forced to option number two.

In-place upgrades have improved considerably, though certain ancillary services (like Machine Learning Services) have breaking changes between versions, so you may be forced into the first route regardless.

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Using the DAC with Dockerized SQL Server

Published 2022-09-27 by Kevin Feasel

Joey D’Antoni needed to use the Dedicated Administrator Connection:

Because as shown in the image above, the table in question is a system_table, in order to query it directly, you need to use the dedicated administrator connection (DAC) in SQL Server. The DAC is a piece of SQL Server that dedicates a CPU scheduler, and some memory for a single admin session. This isn’t designed for ordinary use–you should only use it when your server is hosed, and you are trying to kill a process, or when you need to query a system table to answer a twitter post. The DAC is on by default, with a caveat–it can only be accessed locally on the server by default. This would be connected to a server console or RDP session on Windows, or in the case of a container, by shelling into the container itself. However, Microsoft gives you the ability to turn it on for remote access (and you should, DCAC recommends this as a best practice), by using the following T-SQL.

Read on to see how, as well as what else you’d need to do to get it working.

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Auto-Scaling SQL Managed Instances

Published 2022-09-20 by Kevin Feasel

Amanda Ibrahim answers a customer request:

If the customer needs to configure auto scaling for SQL Managed Instance, where the vCores can be increase and decrease automatically on specific time.

Read on to learn how. This can be useful for dev environments or places where your use case has “office hours”—that is, 90% of your activity takes place during a block of 4-12 hours—and you can afford the time in which the service is unavailable due to scaling.

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Getting Started with SQL Server

Published 2022-09-20 by Kevin Feasel

Lee Markum helps out people new to SQL Server:

I see a lot of questions on data related Reddit forums and data science groups on LinkedIn about how to get started with SQL. Certainly these people mean that they want to learn the SQL language. I don’t think you can do that long term without setting up a home lab. You need your own place to experiment beyond what you can do in an online tutorial where you’re typing into a web browser, for example.

By the time you finish this post, you will be able to install SQL Server for use as a home lab for learning T-SQL and administration of the server environment.

Click through for a step-by-step guide. There’s a lot to learn after walking through this guide but you’ve got to start somewhere.

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