When analyzing response time, or latency, you need much more information than an average provides. The average, commonly the arithmetic mean, shows the index of central tendency. But, as I found in earlier posts, the tendency is often not central, but may be skewed by outliers, or split by multiple modes. How often these factors occur was determined quantitatively, using tests and a survey of hundreds of production servers and different types of latency: over 95% had six-sigma outliers, and at least 20% had multiple modes. While these numerical results are useful, nothing beats a visualization, such as a histogram, …

An article I wrote was posted to the Facebook Engineering blog, about the automation system I worked on at Facebook for MySQL Database Provisioning.

It covers, in fairly intimate detail, a system called "Windex" that we use to provision and re-provision our MySQL databases at Facebook. This system basically provisioned the new Facebook Datacenter in Luleå, Sweden, with very little human effort, saving us loads of time.

So, if you're curious about some of what it is that has been taking up all my time for the last year and some, or if you're just always curious about how Facebook is doing things, go check it out.

Lefred and I spent a bit of time making innotop 1.9.1.
We’ve released a new version mainly to include MySQL 5.6 support as well as including some bugs fixed by Baron Schwartz and Frédéric Descamps.

You can download the .tar.gz and rpm’s (new!) at
http://code.google.com/p/innotop/downloads/list

Bugs fixed:

• Issue 71: DBI prints to STDERR instead of just throwing an inactive statement error
• Issue …

There is a tsunami of blog posts out there as Oracle has made public its 12c database and SQL Server and MySQL with numerous new offerings. This Log Buffer Edition covers a few salient blog posts.

Oracle:

Among the major ETL tools in the market , Oracle Data Integrator outshines not just for a couple of reason. Oracle has invested a lot in developing the tool after it took over from Sunopsis.

You want to learn more about innovative features of WLS 11g and 12c? You want to get answers about the roadmap and capabilities?

Kristin Rose tells us that 12c  offers the latest innovation from …

Here are 3 recent ' oops... wish I hadn't done that :/ ' mistakes I've made since joining moz that you might as well avoid (I'm sure there will be more, but they better not be the same)

Reviewing config files for MySQL, but not all of the defaults 

    We recently migrated a few MySQL databases to a new datacenter, and took advantage of the migration to upgrade the MySQL version(s) at the

This is a followup to my early post a month ago titled: MariaDB replaces MySQL in RHEL 7 (lots of stuff in the comments). It’s clear that MariaDB’s role is in Software Collections, which is new in RHEL.

Steven J. Vaughan-Nichols writes Red Hat will switch from Oracle MySQL to MariaDB, reports.

Sean Michael Kerner has a video (and writeup) with Denise Dumas, RHEL team leader, who talks about Software Collections, MariaDB, and how we’re all friendly …

MySQL 5.6 introduced major advances to monitoring made via PERFORMANCE_SCHEMA, but also made a change in how it binds to the network by default.  In MySQL 5.5, the –bind-address configuration option defaulted to “0.0.0.0″, meaning only IPv4.  This changed to “*” in MySQL 5.6, accepting connections on both IPv6 and IPv4 interfaces.  Somehow (I’ve not looked into it yet), my (unsupported) WindowsXP installation now refuses to bind to IPv4, which caused surprising problems for certain tools that seem to internally map “localhost” …

What is Amazon Redshift and how does it compare to Shard-Query?

Amazon Redshift is the petabyte scale data warehousing system built by Amazon.   It is (currently at the time of this writing)  a beta-quality data warehouse as a service platform hosted in the AWS cloud.   It has has been built from ParAccel technology.  Amazon is an investor in ParAccel.

Amazon Redshift works similarly to Shard-Query.   Both systems allow you to spread data over many machines and treat them as one logical machine.  This architecture  is called “shared nothing” and it has developed the short name “sharding”.

Both systems essentially provide a “virtual database” composed of smaller database.  It is like a RAID array of databases.  You could think of it as a “redundant array of independent databases” in fact.

Sharding

Both Redshift and Shard-Query shard your data …

Some time ago, MySQL Forge went offline.

As part of the Forge dismissal operations, I got a backup of my snippets from the MySQL community team, and I have been lazily looking around for an alternative place where to put them.

I found such a place: Github GIST
Gist is a simple way to share snippets and pastes with others. All gists are git repositories, so they are automatically versioned, forkable and usable as a git repository.

Out of my 25 snippets, these are the ones that still look useful (at least, people have been asking me about those).

• Measuring replication speed
• Poor man's replicator monitor
• …

Join 8000 others and follow Sean Hull on twitter @hullsean. In the past two years we’ve written a ton of material on scalability. Here’s the greatest hits… Why Generalists Are Better at Scaling the Web The internet stack is a complex infrastructure of interlocking components. An scalability engineer must be adept at Linux, plus webservers, […]

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