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Category: Administration

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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Troubleshooting High Threadpool Waits and Deadlocked Schedulers

Published 2020-10-06 by Kevin Feasel

Eitan Blumin takes us through a troubleshooting scenario:

In short, high THREADPOOL waits can happen when SQL Server doesn’t have enough “worker threads” to handle new tasks, which could cause SQL Server to hang and refuse connections. When a task is waiting for a worker thread to become available, that wait type is called THREADPOOL wait.

A background process, called “Scheduler Monitor“, will identify when the same worker threads are “stuck” in the same state for 60 seconds or more. In which case it will resolve the issue as a Deadlocked Scheduler, and that’ll cause dropped connections, rollbacks, and even fail-overs.

When a Deadlocked Scheduler event happens, SQL Server will automatically generate a memory dump file (SQLDump#####.mdmp), and log the incident in the SQL Server Error Log.

Read on to understand what causes this as well as why we always fumble our keys under the car as the scary monster approaches.

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Azure Arc Deployment Options for SQL Server

Published 2020-10-01 by Kevin Feasel

Sasha Nosov takes us through Azure Arc deployment options for SQL Server:

As you can see, both on-Azure and off-Azure options offer you a choice between IaaS and PaaS. The IaaS category targets the applications that cannot be changed because of the SQL version dependency, ISV certification or simply because the lack of in-house expertise to modernize. The PaaS category targets the applications that will benefit from modernization by leveraging the latest SQL features, gaining a better SLA and reducing the management complexity.

Click through for a graphic, as well as further clarification on each item.

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Find and Modify File Growth Settings Across Databases

Published 2020-10-01 by Kevin Feasel

Lori Brown has a challenge:

To some of you out there, that many databases might not be a big deal.  To me, it is a big deal.  That many databases can cause many admin tasks to take a very long time.  One such task is to review all databases to make sure that they are not growing their files by 1MB or 10 Percent, especially the transaction log files.  I find those default settings to not be a good thing generally, and have learned to set files to grow by specified amounts if auto growth needs to occur.  I also try to manually grow data files during maintenance periods but we all know that auto growth happens.

So…how do we find out if our databases have 1MB or 10 Percent file growth set up?

Click through for a script which finds default-sized databases, as well as a script to fix them.

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Finding Unused SQL Server Tables

Published 2020-09-28 by Kevin Feasel

Nisarg Upadhyay shares a few techniques to look for whether a table is currently in use:

In this article, I am going to demonstrate how we can identify the unused tables of a given SQL Database. As a database administrator, we must maintain the tables and objects of the SQL Database. In my organization, when we add a new column or change the data type of a column, we export the data of the existing table in the backup table. Often, we forgot to review and maintain those backup tables. So as a solution, we decided to create a SQL Job that populates the list of unused tables and email the list to the DBA Team for review.

The best way to decommission any table is to rename it first, and if it does not break the functionality of the application, we can drop the table and its dependencies. We decided that after a review of the unused table completes; we will rename the tables and later drop them.

Click through for the techniques and a script which checks tables. It does look fairly reasonable, with the concern being if you restart the SQL Server instance or look at a table which is only accessed at a particular time of year.

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Public Preview of SQL Server on Azure Arc

Published 2020-09-28 by Kevin Feasel

Sasha Nosov gives us an update on Azure Arc:

The preview includes the following features:

– Use Azure Portal to register and track the global inventory of your SQL instances across different hosting infrastructures. You can register an individual SQL instance or register a set of servers at scale using the same auto-generated script.

– Use Azure Security Center to produce a comprehensive report of vulnerabilities in SQL servers and get advanced, real time security alerts for threats to SQL servers and the OS.

– Investigate threats in SQL Servers using Azure Sentinel 

– Periodically check the health of the SQL Server configurations and provide comprehensive reports and remediation recommendations using the power of Azure Log analytics.

Click through for more information and documentation.

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Stellar Repair: A Review

Published 2020-09-25 by Kevin Feasel

Grant Fritchey reviews a product which attempts to repair corrupted SQL Server databases:

Let’s start with the most important piece of information you need: it works.

The software itself is really simple to use and just does what you need, repairs your corrupted SQL Server instance. On that alone, I can recommend the tool.

However, there are a few gotchas I ran into along the way. Mostly, little stuff. It’s things a little polish in the UI and some clean up around language could help out. Don’t get me wrong, I’m happy with this software. It worked. It’s just how it works that we should talk about.

Click through for Grant’s full review.

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