Press "Enter" to skip to content

Category: Linux

Configuring Memory Limits for SQL Server in Kubernetes

Anthony Nocentino doesn’t have all the RAM in the world:

With that Pod deployed, I loaded up a HammerDB TPC-C test with about 10GB of data and drove a workload against our SQL Server. Then while monitoring the workload…boom HammerDB throws connection errors and crashes. Let’s look at why.

First thing’s first, let’s check the Pods status with kubectl get pods. We’ll that’s interesting I have 13 Pods. 1 has a Status of Running and the remainder have are Evicted. 

Anthony does a great job of explaining the problem and showing you the solution.

Leave a Comment

Non-Root SQL Server 2019 Containers

Vin Yu announces a change to Microsoft’s container configuration for SQL Server 2019:

The application process within most Docker containers is running as a root user meaning the process has root privileges within the container user space. The root user within the container is also the same root (uid 0) on the host machine, and if the user can break out of the container, they would have root permissions on the host. Running as root is convenient for development, testing and CI/CD use cases but for production use cases, it is safest to run SQL Server as a non-root process within the container. In this blog, we’re going to share with you how you can preview this upcoming improvement by creating your own non-root SQL Server container.

Vin has a quick demonstration of how it works.

Comments closed

strace and SQL Server Containers

Anthony Nocentino tries using strace to diagnose SQL Server process activity in a container:

We’re attaching to an already running docker container running SQL. But what we get is an idle SQL Server process this is great if we have a running workload we want to analyze but my goal for all of this is to see how SQL Server starts up and this isn’t going to cut it.
 
My next attempt was to stop the sql19 container and quickly start the strace container but the strace container still missed events at the startup of the sql19 container. So I needed a better way.

Don’t worry—Anthony finds a better way.

Comments closed

CPU Usage DMV in SQL Server on Linux

Tejas Shah announces an improvement to sys.dm_os_ring_buffers in SQL Server 2019 RC1 on Linux:

Sys.dm_os_ring_buffers DMV has been a key DMV used for monitoring SQL Server by built-in tools as well as third party monitoring utilities. When SQL Server 2017 was released on Linux, unfortunately this DMV did not return correct CPU usage information by SQL Server process. SQL Server team is glad to announce that the starting with SQL Server 2019 release candidate, the sys.dm_os_ring_buffers DMV returns SQL CPU utilization correctly. This improvement should benefit the SQL Server monitoring ecosystem on Linux by providing a way to monitor SQL Server CPU usage and enable decision making to engage corrective action if required.

This brings it in line with what we have on Windows.

Comments closed

Merge Replication on Linux

Jignesh Raiyani shows how you can set up merge replication on SQL Server on Linux:

In this article, we will discuss to deploy SQL Server Merge Replication on Linux environment. Many SQL Server features are not available on Linux by Microsoft but the Replication feature exists for Linux Environment Edition. Before starting anything, let’s address this question – what is Merge Replication?

Merge Replication is a data synchronization process with one database (Publisher) to other databases (Subscriber) and vice versa. The data synchronization audit will be controlled by the distributor (Distribution database). The distributor database will manage the data synchronization between Publisher and Subscribers.

Merge replication is also an unending nightmare of pain, but you do what you gotta do.

Comments closed

Supported Distributions for SQL Server on Linux

Kevin Chant looks at each of the supported distributions for installing SQL Server on Linux:

Another key point is that even though SQL Server on Linux is supported on various distributions SQL Server can be installed on other distributions instead.

Although I would only advise this for testing purposes only because SQL Server would not be supported by Microsoft on these other distributions.

In reality, you can probably install SQL Server on more diverse distributions than the ones listed. However, I have focused on the main ones below.

As Kevin points out, there’s a difference between “working” and “supported.” If you’re futzing about with a dev database or trying to learn the platform, go ahead and install it on Elementary or some other unsupported distro. But if you have a production issue, the fact that you installed SQL Server on an ancient version of Slackware may win you plaudits but won’t get you support.

Comments closed

Distributed Transactions on Linux

Tejas Shah and crew announce distributed transactions with SQL Server on Linux:

With SQL Server 2017, a new era was heralded with SQL server being available to deploy on Linux (and Linux based container) systems. While all functionality of the SQL Server engine were brought over as is to SQL Server on Linux, some of the functionality which depended on Windows system processes such as distributed transactions (which relies on MSDTC service) were not brought over immediately.

Well, now your wait is over.

Comments closed

Keeping Bash Scripts Reusable

Kellyn Pot’vin-Gorman explains some of the concepts behind scripting for longevity:

I’m going to admit, that the reason I didn’t embrace Powershell at first, was most of the examples I found were of full of hardcoded values.  I found it incredibly obtuse, but I started to realize that it came from many sources who might not have the scripting history that those of other shells, (this was just my theory, not a lot of evidence to prove on this one, so keep that in mind…)  As Powershell scripts have matured, I’ve noticed how many are starting to build them with more dynamic values and advance scripting options, and with this, I’ve become more comfortable with Powershell.

I think the best way to learn is to see real examples, so let’s demonstrate.

Read on for those examples.

Comments closed

Getting Powershell 7 Preview on Ubuntu

Max Trinidad shows us how to get the Powershell 7 preview without using apt:

First, look under the release documentation and search for the deb package. In my case I’m install the amd64 version.

Then, right-click on the “powershell-preview_7.0.0-preview.2-1.ubuntu.18.04_amd64.deb”, and select “Copy link address“.

This is also something you could script out. It’s quite useful in scenarios where your apt repositories don’t have the latest version of something but you still need or want it.

Comments closed