If you run (or plan to deploy) high availability clusters — with or without DRBD — you might find a new section on our web site handy. Our Technical Guides collection is a compilation of LINBIT expert HA knowledge, which we’re opening up to everyone.

Yes, this also includes PDF versions of the DRBD User’s Guide and the Linux-HA User’s Guide.

More Technical Guides will be added as we go along. LINBIT Cluster Stack support customers will receive new Tech Guides approximately one month before they pop up on …

Found this video regarding Netflix's migration to Amazon's AWS cloud very informative. Enjoy!

We had some technical difficulties with Webex today which prevented from all registered attendees to be able to join webinar. I personally would be very upset having booked my time to attend event, pre-registered to ensure there is a space available and when unable to join at the time of event (which is frankly exactly what happened to me).

As result we have scheduled Migrating MyISAM to Innodb webinar to run again on Tuesday, December 7 at 9AM Pacific (Same Time). Here is direct link if you would like to register.

Note we also Webinar on Percona Server, Xtrabackup and XtraDB next week which is great if …

Amazon's AWS team has published a series of whitepapers covering various scenarios for migrating into AWS cloud infrastructure. Links to these whitepapers are provided below for your convenience:

- Migrating applications to the AWS cloud
- Migrating web application
- Migrating batch processing applications
- Migrating backend processing pipelines

Googling around, I came across Bradford Cross' article, Big Data Is Less About Size, And More About Freedom. Bradford writes, " The scale of data and computations is an important issue, but the data age is less about the raw size of your data, and more about the cool stuff you can do with it."

Even though the article makes some good points, I'm not sure I can agree with Bradford's point of view here. As an architect, when I think in terms of Big Data, the ability to do "cool stuff" is probably the last thing that crosses my mind. Big Data, to me, is about ensuring constant response time as the data grows in size without sacrificing functionality.

What do you think Big Data is about? Is it merely about being able to do 'cool stuff' with your data? Is it about ensuring constant access/response times? Or is it about something else? I'm eager …

The following quirky dynamic SQL will scan each index of each table so that they’re loaded into the key_buffer (MyISAM) or innodb_buffer_pool (InnoDB). If you also use the PBXT engine which does have a row cache but no clustered primary key, you could also incorporate some full table scans.

To make mysqld execute this on startup, create /var/lib/mysql/initfile.sql and make it be owned by mysql:mysql

SET SESSION group_concat_max_len=100*1024*1024;
SELECT GROUP_CONCAT(CONCAT('SELECT COUNT(`',column_name,'`) FROM `',table_schema,'`.`',table_name,'` FORCE INDEX (`',index_name,'`)') SEPARATOR ' UNION ALL ') INTO @sql FROM information_schema.statistics WHERE table_schema NOT IN ('information_schema','mysql') AND seq_in_index = 1;
PREPARE stmt FROM @sql;
EXECUTE stmt;
DEALLOCATE PREPARE stmt;
SET SESSION group_concat_max_len=@@group_concat_max_len;

and in my.cnf add a line in the [mysqld] block

init-file = …

This quick guide will walk you through setting up OpenVZ on CentOS. I followed these steps on CentOS release 5.5 x64 version. If you want more detail on install via different methods and/or have different flavor of CentOS and run into an issue, you can follow instructions provided by OpenVZ site. Once you are done with this guide, you will have CentOS container running for you to play with.

For my purposes, I started with very basic installation of CentOS 5.5. I have done this on existing installations of CentOS without any issues as well. Ok so let’s start with getting the OpenVZ repository added to our system. This means that we will be going down “yum” path instead of “rpm” path. This is the quickest and easiest way to get OpenVZ installed.

cd /etc/yum.repos.d
wget http://download.openvz.org/openvz.repo
rpm --import …

Here you find information about writing LEFT JOINs (also referred to as LEFT OUTER JOINs). This introduction into left joins includes a description, syntax information and example statements that use left outer joins. The Venn diagram on the left represents a result set that a statement with a left join produces. Please refer to the syntax examples below for an example. Links to additional information resources can be found at the end of this article.

Left Join syntax

First of all, some syntax examples for the impatient:

-- left join with USING-clause
SELECT *
FROM <leftTable> LEFT JOIN <rightTable>
USING(id)

-- left join with ON-clause
SELECT *
FROM <leftTable> a LEFT JOIN <rightTable> b
ON a.name = b.authorName

As you can see, a join condition can be written …

Alaric Snell-Pym discusses why choose between SQL and NoSQL? Why can't you use both in your infrastructure?

"NoSQL engines abandon SQL for the chance to have more flexible data models and softer semantics for update operations - but they also abandon it because it’s a lot of work to implement. And, creating a new database from scratch, they’re keen on solving the interesting hard problems (such as replicated data storage), rather than following the well-trodden path of writing SQL parsers and query planners, with a few decades of catching up with the competition ahead of them."

I hate it when recruiters reach out to you with a message indicating that they are looking for 'key positions' and when you follow up, the tone changes to "we're just looking for engineers." This happens all the time and the latest company to play this recruitment tactic is LinkedIn. Guys, can't you decide whether you are looking to fill a 'key position' or just an engineering position before reaching out to candidates? I can see that mentioning 'key position' will get a candidate's attention but this is just a low level tactic.