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Displaying posts with tag: Open Source (reset)
In Depth: MySQL 5.6+ DDL


DDL (Data Definition Language) statements create, alter, and remove database objects. These types of changes can be a very dangerous action to take on such a critical piece of your infrastructure. You want to make sure that the command that you are executing has been given proper thought and testing.

In this post I go through multiple version of MySQL and verify the best course of action to take in regards to executing DDL statements.  There are many things that you have to consider when making these types of changes, such as disk space, load on the database server, slave replication, the type of DDL statement you are executing, and if it will lock the table. 

Because of these risks, there are tools that can be used to help mitigate some of the dangers. But unless you have tested and verified their functionality, these tools in themselves can cause trouble. Whenever in doubt, take the time to test …

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MySQL on FreeBSD: old genes

Maintaining mission critical databases on our pitchfork wielding brother, the “Daemon” of FreeBSD, seems quite daunting, or even absurd, from the perspective of a die-hard Linux expert, or from someone who has not touched it in a long time. The question we ask when we see FreeBSD these days is “why?”.  Most of my own experience with FreeBSD was obtained 10-15 years ago.  Back then, in the view of the team I was working on, a custom compiled-from-source operating system like FreeBSD 5.x or 6.x was superior to a Linux binary release.

Package managers like YUM and APT were not as good.  They did not always perform MD5 checks and use SSL like today’s versions. RedHat wasn’t releasing security updates 5 minutes after a vulnerability was discovered. Ubuntu didn’t exist. Debian stable would get so very old before receiving a new version upgrade. FreeBSD was a great choice for a maintainable, secure, free open …

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MySQL Yum Repo Setup On Vagrant & VirtualBox

Today I start this MySQL blog which will apply a focus on all things MySQL and attempt to bring out their practical usage.  In this particular blog I will give an introduction to MySQL by helping us all get a simple way to test new MySQL features or capabilities through the usage of Vagrant, Virtual Box and then setting… Read More »

Data Encryption at Rest

This blog post was co-authored by Peter Sylvester and Valerie Parham-Thompson

Introduced in version 10.1.3 (and with substantial changes in 10.1.4), the MariaDB data encryption at rest feature allows for transparent encryption at the tablespace level for various storage engines, including InnoDB and Aria.

Before now, there have been only two widely accepted encryption methods for MySQL/MariaDB: encryption at the file system level, or encryption at the column level. For comparison, we’ll do a brief overview of how these work, as well as the pros and cons typically associated with each option.

File System Encryption

This is performed by setting a file system to be encrypted at the block level within the operating system itself, and then specifying that the encrypted volume should be the location of the data directory for MySQL/MariaDB. You can also use encrypted volumes to store MariaDB binary logs. …

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Hello dear readers and attendees,

This is the post that I will be/ will have been referencing during my presentation to the Seattle Central Community College’s Byte club on Thursday, December 10th at 1500-1630.

I will begin with a bit of an autobio and find out what kind of students we have in attendance. Please feel free to comment if you’d like to keep in touch before or after the presentation. I will discuss some of the bits and pieces of some industry standard platforms which I’ve developed, deployed, maintained, managed, co-operated, administered and replaced. We can discuss some of the patterns that work well in the industry, and some that are a bit harder to tame.

Once we have touched most of the areas of specialization represented at the meeting, I will dive in to an AngularJS demo I am developing in github here:

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Amazon RDS Migration Tool

Amazon has just released their RDS Migration Tool, and Pythian has recently undertaken training to use for our clients. I wanted to share my initial thoughts on the tool, give some background on its internals, and provide a walk-through on the functionality it will be most commonly used for.

There are many factors to consider when evaluating cloud service providers, including cost, performance, and high availability and disaster recovery options. One of the most critical and overlooked elements of any cloud offering though, is the ease of migration. Often, weeks are spent evaluating all of the options only to discover after the choice is made that it will take hours of expensive downtime to complete the migration, and that there is no good rollback option in the case of failure.

In order to reduce the friction inherent in the move to a DBaaS offering, Amazon has developed an RDS Migration tool. This is an in-depth look at this new …

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Orchestrator visual cheatsheet, TL;DR the "smart" way

Orchestrator is really growing. And the amount of users (DBAs, sys admins) using it is growing. Which gives me a lot of immediate feedback in the form of "Look, there's just too many options to move slaves around! Which ones should we use?"

TL;DR look at the two visualized commands below

They are enough

The "smart" commands to end all commands

So all relocation commands are important, and give you fine-grained, pin-pointed control of the method of topology refactoring. However, most of the time you just want to move those servers around. Which is why there's a new "smart" mode which support these two commands, which you should be happy using:

  • relocate: move a single slave to another position
  • relocate-slaves: move …
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Orchestrator 1.4.340: GTID, binlog servers, Smart Mode, failovers and lots of goodies

Orchestrator 1.4.340 is released. Not quite competing with the MySQL latest changelog, and as I haven't blogged about orchestrator featureset in a while, this is a quick listing of orchestrator features available since my last publication:

  • Supports GTID (Oracle & MariaDB)
    • GTID still not being used in automated recovery -- in progress.
    • enable-gtid, disable-gtid, skip-query for GTID commands
  • Supports binlog servers (MaxScale)
    • Discovery & operations on binlog servers
    • Understanding slave repositioning in a binlog-server architecture
  • Smart …
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Tungsten Replicator moved to GitHub with Apache license

It had been in the making for long time. Google announced that Google Code would be closing, and since then the Continuent team has been hard at work to handle the transition. You can guess it: this operation would have been quicker if it had been done by a small company like we were one year ago, but being part of a large corporation introduces some constraints that have affected our schedule.

However, our wish has always been, and still is, to keep Tungsten Replicator as an open source product, with full functionalities and with the full benefits that the open source development model offers.

Today, Tungsten Replicator is available on GitHub as …

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fsfreeze in Linux

The fsfreeze command, is used to suspend and resume access to a file system. This allows consistent snapshots to be taken of the filesystem. fsfreeze supports Ext3/4, ReiserFS, JFS and XFS.

A filesystem can be frozen using following command:

# /sbin/fsfreeze -f /data

Now if you are writing to this filesystem, the process/command will be stuck. For example, following command will be stuck in D (UNINTERUPTEBLE_SLEEP) state:

# echo “testing” > /data/file

Only after the filesystem is unfreezed using the following command, can it continue:

# /sbin/fsfreeze -u /data

As per the fsfreeze main page, “fsfreeze is unnecessary for device-mapper devices. The device-mapper (and LVM) automatically freezes filesystem on the device when a snapshot creation is requested.”

fsfreeze is provided by the util-linux package in RHEL systems. Along with userspace support, fsfreeze also …

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