Press "Enter" to skip to content

Category: Bugs

Apache Zookeeper Vulnerability

Published 2023-10-24 by Kevin Feasel

The Instaclustr team reviews an announcement:

On October 11, 2023, the Apache ZooKeeper™ project announced that a security vulnerability has been identified in Apache ZooKeeper, CVE-2023-44981. The Apache ZooKeeper project has classified the severity of this CVE as critical. The CVSS (Common Vulnerability Scoring System) 3.x severity rating for this vulnerability by the NVD (National Vulnerability Database) is base score 9.1 Critical.  

That’s a rather high base score and is comes about if you have the setting quorum.auth.enableSasl=true. Updating to the Zookeeper 3.7.2 or alter, 3.8.3 or later, or anything in the 3.9 branch will fix this vulnerability.

Comments closed

File Not Found in SQL Server 2022 with Distributed AG and Filestream

Published 2023-08-28 by Kevin Feasel

Sean Gallardy goes sleuthing:

I don’t often find many people using FileStream in their databases (which isn’t a bad or good thing, in my opinion, just a statement of fact). Some technologies in SQL Server use it behind the scene, such as FileTable or Hekaton, and there isn’t really any getting around it in those cases. However, I was brought an interesting issue by a friend on Database Administrators Stack Exchange, Hannah Vernon (w), when it came to a database that was in a Distributed Availability Group in 2019 and had no issues, but after upgrading to SQL Server 2022, started having a major problem.

Read on for Sean’s analysis of the problem and solution.

Comments closed

Thoughts on Parameter Sensitive Plan Optimization

Published 2023-08-15 by Kevin Feasel

Jared Poche shares some thoughts:

First, I wanted to point out that there are fixes to issues specific to Parameter Sensitive Plan Optimization in SQL Server 2022. The issue itself is documented at the link below.

https://learn.microsoft.com/en-us/sql/relational-databases/performance/parameter-sensitive-plan-optimization?view=sql-server-ver16#known-issues

When I heard about the issue, I heard that it could cause SQL Server 2022 to cause stack dumps every 15 minutes. The time interval made me think it was related to the default interval for Query Store, and that seems to be the case.

Jared has several thoughts on the topic as he puts together a talk on PSPO.

Comments closed

Bug in fn_xe_file_target_read_file

Published 2023-07-17 by Kevin Feasel

Erik Darling notes a bug:

SQL Server has had the fn_xe_file_target_read_file function for a while, but starting with SQL Server 2017, a column called timestamp_utc was added to the output.

Somewhat generally, it would be easier to filter event data out using this column… if it worked correctly. The alternative is to interrogate the underlying extended event XML timestamp data.

That’s… not fun.

Erik shows us the problem and also provides a workaround, as well as the Microsoft Feedback issue you can vote on to get this done sooner.

Comments closed

Bugs in SQL Server 2022 CU4

Published 2023-05-29 by Kevin Feasel

Brent Ozar facepalms:

<sigh> Okay, so, the last few Cumulative Updates have had known issues around broken remote queries using the generic ODBC connector and errors with contained availability groups, but I couldn’t really care less about those. If you use those features, I give you bombastic side eye anyway.

However, in the last few days, two more known issues have surfaced.

And those two issues are definitely bad. Click through to see what they are and what the workarounds are until fixes come in.

Comments closed

PolyBase Generic ODBC Bug in 2019 CU19 and 2022 CU2

Published 2023-04-06 by Kevin Feasel

Nathan Schoenack warns us of a bug in SQL Server:

After you install SQL Server 2019 CU19 or SQL Server 2022 CU2, external data sources using generic ODBC connector may no longer work. When you try to query external tables that were created before installing the cumulative update, you receive the following error message:

Msg 7320, Level 16, State 110, Line 68

Cannot execute the query “Remote Query” against OLE DB provider “MSOLEDBSQL” for linked server “(null)”. Object reference not set to an instance of an object.

If you try to create a new external table, you receive the following error message:

Msg 110813, Level 16, State 1, Line 64

Object reference not set to an instance of an object.

Click through to learn the cause of the issue and a workaround to resolve it.

2 Comments

Notes on DBATools’s Get-DecryptedObject

Published 2023-01-26 by Kevin Feasel

Sean Gallardy explains an issue:

Let me start off by saying that DBATools is a great tool that is immensely helpful to the community, if you haven’t heard about it or tried it, please give it a shot! I personally believe that the SQL Server community is truly the best out there, with so many people helping each other and developing great, free, tools that benefit all. Having said that, I’ve been asked quite a few times to look into a “SQL Server Bug” decrypting data.

This is not an issue with SQL Server nor is it a bug/feature/whatever. It is, in fact, a bug in the source material for DBATools.

Read the whole thing.

Comments closed

Tracking Database Errors with Extended Events

Published 2022-12-07 by Kevin Feasel

Eitan Blumin is watching you:

But interestingly enough – we would be getting an added benefit here. Even if there is no SQL injection attack, it’s still possible that such errors would be raised by the application – simply due to bugs.

Furthermore, these errors in the database may be happening without anyone even noticing! How could that be, you ask? Well, it could be due to bad error handling that “swallows” the error entirely, or because the errors are logged but no one is bothering to look at the logs, or maybe because the errors are caught but an undetailed error message is logged/displayed to the user (I can’t even count how many times I encountered “general database error” messages in applications), or because the developers simply decided to mark this as a “known issue” that they didn’t bother to fix and they didn’t think to ask their DBA about it… The reasons are numerous and varying.

Click through for the scripts. I had built something similar about a decade ago, a simple WPF app which watched for errors. I messaged him with something like “You missed a comma in that IN clause” and I saw him pop up from his cubicle and look around, trying to figure out how I could peek over his shoulder and see the query.

1 Comment

Debugging Code in R

Published 2022-10-06 by Kevin Feasel

Cosima Meyer explains how debugging works in R with RStudio:

Three basic commands in RStudio let you do the debugging: debug(function_name), browser(), and undebug(function_name).

With debug(function_name) you start the debugging of your function – it’s basically like a mole that digs in. When you’re in debug mode, you can also call the objects in your function.

Read the whole thing to learn the power of debugging beyond the print() statement. H/T R-Bloggers.

Comments closed