So you want to contribute to OpenStack? I can help!

For the last year or so I have been involved with OpenStack and more specifically the Trove (DBaaS) project as sort of an ambassador for Percona, contributing bits of knowledge, help and debugging wherever I could and thought I would share some of my experience with others that wanted to get involved with OpenStack development, documentation, testing, etc. Getting started with OpenStack contributions is also the idea behind my talk next month at Percona OpenStack Live 2015. (Percona Live attendees have access to OpenStack Live)

Back at the last OpenStack Conference and Design Summit in Paris last November, I had the amazing opportunity to attend the two-day …

MySQL QA Episode #1: Bash/GNU Tools & Linux Upskill & Scripting Fun

This episode consists of 13 parts, and an introduction. See videos below

In HD quality (set your player to 720p!)

Introduction

Part 1: echo, ls, cp, rm, vi, cat, df, du, tee, cd, clear, uname, date, time, cat, mkdir

Part 2: find, wc, sort, shuf, tr, mkdir, man, more

Part 3: Redirection, tee, stdout, stderr, /dev/null, cat

Part 4: Vars, ‘ vs “, $0, $$, $!, screen, chmod, chown, export, set, whoami, sleep, kill, sh, grep, sudo, su, pwd

Part 5: grep, regex (regular expressions), tr

Part 6: sed, regex (regular expressions)

Part 7: awk

Part 8: xargs

Part 9: subshells, …

Welcome to the MySQL QA Training Series!

If you have not read our introductory blog post on pquery yet, I’d recommend reading that one first to get a bit of background. The community is enthuastic about pquery, and today I am happy to announce a full training series on pquery and more. Whether you are a Linux or MySQL newbie or a seasoned QA engineer, there is something here for you. From Bash scripting (see episode 1 below), to every aspect of the new pquery framework, it is my hope that you enjoy this series. If you do, please leave us a comment

Database quality assurance is not as straightforward as it may seem. It’s not a matter of point-and-click, but rather of many intertwined tools and scripts. Beyond that, due to the complexity of the underlying product, it’s about having an overall plan or …

One of our Percona Support customers recently reported that Percona XtraBackup failed with a page corruption error on an InnoDB table. The customer thought it was a problem or bug in the Percona XtraBackup tool. After investigation we found that an InnoDB page was actually corrupted and a Percona XtraBackup tool caught the error as expected and hence the backup job failed.

I thought this would be an interesting topic and worthy of a blog post. In this article I will describe the innochecksum tool, when and how to use it and what are the possible fixes if an InnoDB table suffers from …

My webinar “Multi-threaded Replication in MySQL 5.6 and 5.7″ on February 25 generated several excellent questions following the presentation (available here for playback along with the slides). I didn’t have time to answer many of the questions during the session and so in this post I answer all of them. Thanks to everyone who attended!

Q: What do you expect from MTS with logical clock? Do you think performance would be good as with per database?
A: MTS with 5.6 is not usable if you have a single database. I do not have numbers, but this is quite frequent. With 5.7 everyone should be able to benefit from multi-threaded replication.

Q: When MySQL 5.6 was released, performance of MTS was lower, than in 5.5, for example. Is this addressed now?
A: I am not sure which …

The MySQL Performance Schema exposes so much data that it’s not trivial to learn, configure, and use. With recently released Percona Agent 1.0.11 you can get query metrics – like min, max, and average query execution time – with a few clicks:

Click “Apply” and about two minutes later you’ll have query metrics from Performance Schema, collected and sent every minute.

Percona Cloud Tools (PCT) and Percona Agent handle all the details. You’ll need MySQL (or Percona Server) 5.6 and Percona Agent 1.0.11 or newer. One caveat at the moment: it …

What is JSON

JSON is an text based, human readable format for transmitting data between systems, for serializing objects and for storing document store data for documents that have different attributes/schema for each document. Popular document store databases use JSON (and the related BSON) for storing and transmitting data.

Problems with JSON in MySQL

It is difficult to inter-operate between MySQL and MongoDB (or other document databases) because JSON has traditionally been very difficult to work with. Up until recently, JSON is just a TEXT document. I said up until recently, so what has changed? The biggest thing is that there are new JSON UDF by Sveta Smirnova, which are part of the MySQL 5.7 Labs releases. Currently the JSON UDF are up to version 0.0.4. While these new UDF are a welcome edition to the MySQL database, they don’t solve the really tough …

MySQL Replication is very simple to set up. In this post I’ll discuss its importance and five handy tools for monitoring and managing MySQL replication.

What is MySQL Replication? It’s the process of copying the (real-time events) data from one master instance to another slave instance and maintaining the redundant consistent data in a different machine. This enables a distributed database system that shares the same level of information.

In MySQL the replication works based on the three threads as shown below.

1) I/O thread on the slave server:  To start on receiving replication events, an I/O thread starts on the slave server and connects to the master server.

2) Master connection handler thread:  As a connection handier, master starts a thread whenever a replication slave connects to a master. The master server sends the events from its binary log file to the slave I/O thread, notifying slave …

Have you ever had a case where you needed to find a process which sent a HUP/KILL/TERM or other signal to your database? Let me rephrase. Did you ever have to find which process messed up your night? If so, you might want to read on. I’m going to tell you how you can find it.

Granted, on small and/or meticulously managed systems tracking down the culprit is probably not a big deal. You can likely identify your process simply by checking what processes have enough privileges to send mysqld a HUP/KILL/TERM signal. However, frequently we see cases where this may not work or the elimination process would be too tedious to execute.

We recently had a case where a process was frequently sending SIGHUPs to mysqld and the customer asked us to see if we could get rid of his annoyance. This blog is the direct result of a discussion I had with my colleague …

The CVE-2015-0204 FREAK SSL vulnerability abuses intentionally weak “EXPORT” ciphers which could be used to perform a transparent Man In The Middle attack. (We seem to be continually bombarded with not only SSL vulnerabilities but the need to name vulnerabilities with increasing odd names.)

Is your server vulnerable?

This can be tested using the following GIST

If the result is 0; the server is not providing the EXPORT cipher; and as such is not vulnerable.

Is your client vulnerable?

Point your client to https://oneiroi.co.uk:4443/test if this returns “Vulnerable” then the client is vulnerable, if you find a connection error your client should not be vulnerable for example:

root@host:/tmp$ openssl …