In this blog post, we’ll look at how ioping can be used with other tools to understand and troubleshoot storage performance, specifically as it relates to MySQL workloads.

I recently ran into ioping, a nice little utility by Konstantin Khlebnikov that checks storage latency.  

For me, the main beauty of ioping is its simplicity and familiarity. It takes after the ubiquitous ping tool, but “pings” the storage instead of the network device.

First, let’s talk about what this tool isn’t: it isn’t a benchmark tool to stress load your storage as heavily as possible. For that, you can use iozone or sysbench (among many others). This also isn’t a tool for looking at …

Occasionally at conference or a Meetup, someone will approach me and ask me for help with a MySQL problem.  Eight out of ten times their difficulty includes a sub query. "I get an error message about a corrugated or conflabugated sub query or some such,"  they say, desperate for help.  Usually with a bit of fumbling we can get their problem solved.  The problem is not a lack of knowledge for either of us but that sub queries are often hard to write. 

MySQL 8 will be the first version of the most popular database on the web with Common Table Expressions or CTEs.  CTEs are a way to create temporary tables and then use that temporary table for queries. Think of them as easy to write sub queries!

WITH is The Magic WordThe new CTE magic is indicated with the WITH clause.

mysql> WITH myfirstCTE 
      AS (SELECT * FROM world.city WHERE …

Percona announces the GA release of Percona Server for MySQL 5.7.20-19 on January 3, 2018. Download the latest version from the Percona web site or the Percona Software Repositories. You can also run Docker containers from the images in the Docker Hub repository.

Based on MySQL 5.7.20, including all the bug fixes in it, Percona Server for MySQL 5.7.20-19 is the current GA release in the Percona Server for MySQL 5.7 series. …

Happy New Year to everyone!
I published an article about row numbering and ranking with MySQL, here.

Not long ago we had an internal discussion about security and how to enforce a stricter set of rules to prevent malicious acts, and block other undesired queries.

ProxySQL comes up as a possible tool that could help us in achieving what we were looking for. Last year I had written how to use ProxySQL to stop a single query.

That approach may be good for few queries and as temporary solution. But what can we do when we really want to use ProxySQL as an SQL-based firewall? And more importantly, how to do it right?

First of all, let us define what “right” can be in this context.

For right I mean an approach that will allow us to have rules matching as specific as possible, and impacting the production system as least as possible.

To make this clearer, …

Thank you for attending my webinar on Wednesday, December 20, 2017, InnoDB Performance Optimization. In this blog, I will provide answers to the Q & A for the webinar.

Are the T2 CPUs similar to the M4 series?

I would expect them to be similar. Amazon does not disclose what specific version of CPUs they use for T2 instances. More details are available here.

Delay in spinlock code is pretty old code. Need to optimize based on today’s CPU? Your views?

There have been a number of improvements to the InnoDB Spinlock code during the last few years. For example, using CPU wait …

Join Percona Chief Evangelist Colin Charles as he covers happenings, gives pointers and provides musings on the open source database community.

Happy New Year. Here’s to 2018 being a great year in the open source database world. What is in store for us? Probably: MySQL 8.0 and MariaDB Server 10.3 as generally available. What will we see in the rest of the space? Clouds? All I know is that we move fast, and it’s going to be fun to see what unfolds.

The biggest news this week may not necessarily be database related; it focused on CPU security vulnerabilities and the potential slowdowns of your servers once the updates are applied. Please do read Meltdown and Spectre: CPU Security Vulnerabilities. Peter Zaitsev himself, got quoted in …

Update: I included the results for when PCID is disabled, for comparison, as a worse case scenario.

After learning about Meltdown and Spectre, I waited patiently to get a fix from my OS vendor. However, there were several reports of performance impact due to the kernel mitigation- for example on the PostgresQL developers mailing list there was reports of up to 23% throughput loss; Red Hat engineers report a regression range of 1-20%, but setting OLTP systems as the worse type of workload. As it will be highly dependent on the hardware and workload, I decided of doing some test myself for the …

In this blog post, we examine the recent revelations about CPU security vulnerabilities.

The beginning of the new year also brings to light fresh and new CPU security vulnerabilities. Today’s big offenders originate on the hardware side – more specifically, the CPU. The reported hardware kernel bugs allow for direct access to data held in the computer/server’s memory, which in turn might leak sensitive data. Some of the most popular CPUs affected by these bugs are Intel, AMD and ARM.

The most important thing to know is that this vulnerability is not exploitable remotely, and requires that someone execute the malicious code locally. However, take extra precaution when running in virtualized environments (see below for more information).

A full overview (including a technical, in-depth …

Percona announces the release of Percona Toolkit 3.0.6 on January 4, 2018.

Percona Toolkit is a collection of advanced command-line tools that perform a variety of MySQL and MongoDB server and system tasks too difficult or complex for DBAs to perform manually. Percona Toolkit, like all Percona software, is free and open source.

You download packages from the website or install from official repositories.

This release includes the following changes:

New Features:

• PT-221: Improve pt-table-sync support for …