January 20, 2014 By Severalnines

Alfresco is a popular collaboration tool available on the open-source market. It is Java based, and has a content repository, web application framework and web content management system. For critical large-scale implementations that require 24*7 uptime, a multi-node cluster would be appropriate. Since Alfresco depends on external components such as the database and the filesystem, clustering the Alfresco instances only would not be enough.

In this post, we are going to show you how to deploy an active-active Alfresco cluster with MySQL Galera Cluster (database), GlusterFS (filesystem) and HAproxy with Keepalived (load balancer) to achieve redundancy of all the required system components.

Please note that clustering of Alfresco instances is only available in the Alfresco Enterprise. Hazelcast is used …

MySQL's architecture and features make the database a great fit for cloud based deployments. If you are interested in using MySQL to deliver web-based applications and scale out, read the white paper MySQL, An Ideal Choice in the Cloud.

As a first step to using the MySQL database, take the MySQL for Beginners course. In this 4-day course, you learn to use the MySQL Server and tools while developing a knowledge of relational databases. You can take this course through the following delivery methods:

• Training-on-Demand: Start training within 24 hours of registering and train at your own pace.
• Live-Virtual Event: Follow a live …

Mon, 2014-01-20 09:00tomcallway

We’ve been busy at SkySQL these past few months! Now we’re proud to introduce MariaDB Enterprise Release 1.0 to our customers and to the MySQL ecosystem. This new product is a milestone for SkySQL’s product portfolio, delivering easy installation, configuration and management of sophisticated high availability solutions based on MariaDB and Galera Cluster to customers eager to leverage this technology, but put off by its inherent complexities.

MariaDB Enterprise has an API layer as its foundation. The GUI tool which you use to provision, monitor and manage your cluster does all of its work through calls to the RESTful API, including provisioning cluster nodes on bare metal Linux boxes or newly instantiated virtual machines or AMIs. By packaging up the product’s capabilities in this API, we’ve both made it easy to manage Galera Clusters through our GUI, and also provided a powerful tool to …

I have recently moved to HP's Advanced Technology Group which is a new group in HP and as part of that I will be blogging a lot more about the Open Source things I and others in HP work on day to day.  I thought I would kick this off by talking about work that a colleague of mine, Patrick Crews, worked on several months ago.

For those who don't know Patrick, he is a great Devops Engineer and QA.  He will find new automated ways of breaking things that will torture applications (and the Engineers who write them). I don't know if I am proud or ashamed to say he has found many bugs in code that I have written by doing the software equivalent of beating it with a sledgehammer.

Every Devops Engineer worth his salt knows that backups are important, but one thing that is regularly forgotten about is to check whether the backups are good.  A colleague of mine …

Another obscure issue I ran into not long ago was when using MySQL Workbench, and clicking on a table, it became stuck in fetching mode.

What triggered the issue was a recent MySQL upgrade, but MySQL itself, not Workbench.

After checking the error log, we saw an error like:

Incorrect definition of table mysql.proc: expected column
'comment' at position 15 to have type text, found type char(64)

Instantly, I knew mysql_upgrade needed to be ran in order to fix the “Incorrect definition” issue, and turns out that is the root cause for Workbench getting stuck in the “fetching” mode.

So the solution is to run mysql_upgrade. Should that not fix the table for some reason, then you can also fix it alternatively with:

ALTER TABLE mysql.proc MODIFY `comment` text
CHARACTER SET utf8 COLLATE utf8_bin NOT NULL;
FLUSH TABLES;

Hope this helps.

In October I briefly introduced ProxySQL , a prototype to perform caching, load balancing and query rewrite. In light of its initial promising performance, in the months I redesigned and re-architectured it almost completely, in a way that is now easier to solve many important issues in the MySQL ecosystem:- load balancing;- read/write split;- caching reads outside the database server;- on-the-fly rewrite of queries;- query routing;All of these features are completely transparent to the application layer, and gives numerous benefits:- increased throughput and reduced latency, for both write and read workload;- simplified clients configuration;- optimize applications that generate bloated queries (most of the ORMs do that).This results in faster setups, improved users experience, and optimized usage of resources (hardware, software, but also …

Since MySQL Workbench 6.0 isn’t available for Fedora, Version 20, I’m having my students install it on their local Windows and Mac OS X operating systems. You can configure the /etc/sysconfig/iptables file to enable port 3306 after installing MySQL on Fedora.

You can open a port by adding the following line to the /etc/sysconfig/iptables file (Fedora’s instructions on editing iptables). The file won’t exist initially, but you can create it by running the following command as the root superuser or sudoer:

shell> service iptables save

You you can run the following commands as the root superuser, …

When looking back at 2013, one of the things that really stand out is what we’ve done with MySQL in Linux distros. At least it stands out to me, but for most people it’s probably the janitorial work that they never notice as long as everything keeps working perfectly. Although invisible to most, this is the important work that makes it possible for all Linux users to run MySQL.

Most distros are maintained by volunteers doing packaging work in their spare time, and we as software developers should be very grateful for all the work and effort they put into distributing our software (for free!). I know we at Oracle are!

We’ve had a distro-like project of our own in 2013. We have created our own repositories for various Linux distros (I hope to see more in the future), so that users that want the latest and greatest can get that even if their …

I ran into a rather obscure bug the other day, but while uncommon, it can cause damage you would not otherwise expect if you use file-level symbolic links. So this is just a warning about that.

Specifically, if you create a table with the .MYI and .MYD files in a different directory, using symbolic links – either manually or using CREATE TABLE .. INDEX DIRECTORY=”" DATA DIRECTORY=”", and then run myisamchk on the table and specify .MYI, you will corrupt the table.

Creating these manually is not so common, but the CREATE TABLE .. INDEX DIRECTORY=”" DATA DIRECTORY=”" is much more common, which creates file-level symbolic links (for the .MYI and .MYD files, respectively) in the datadir and stores the actual file(s) in the location specified. So it leaves you with this setup.

Therefore, if you later run myisamchk on one of these files, do not specify .MYI in the command invocation. If you invoke myisamchk –help, …

Dear Perl and MySQL community,

I’m pleased to announce the release of DBD::mysql 4.026

In this release:

2014-01-15 Patrick Galbraith, Michiel Beijen, DBI/DBD community (4.026)
* t/29warnings.t fails on MySQL Server 5.1.something - Reported by RT91202, Gisle Aas. Now is handled depending on version.
* README.pod misses proper NAME heading - RT90101 - Damyan Ivanov, Debian Perl Group
* Added fix and test for RT91715 (ability to obtain $dbh->{mysql_use_result} value)
* Added feature from Jacob Gelbman (cPanel) mysql_skip_secure_auth

Thanks to everyone who contributed!

For more information: http://search.cpan.org/~capttofu/DBD-mysql-4.026