What’s the connection between databases and fruit flies?
Some of you may be familiar with the bestseller in business literature The Innovator's Dilemma: When New Technologies Cause Great Firms to Fail, by Harvard professor Clayton Christensen. In his book, Prof. Christensen compared disk drives to fruit flies. The comparison relates to the rapid changes that disrupted the disk drive industry for decades. That disruption is compared to the rapid changes that take place to fruit flies that live only for few hours, and for this reason researchers can study and analyse their behaviour.

In the software business, you can replace disk drives with databases. Obviously, databases live longer than fruit flies, but it is an industry that sometimes shows schizophrenic changes. Whilst it is true that relational databases have being dominated the scene for decades, readers with grey hair and reading glasses have …

http://webscalesql.org/

yeah , big buzz around that one

So I decided to check the install process:

1. Clone the repo from

root@webscalesql-5.6.clean:[Mon Mar 31 11:37:11][~]$ cd /opt/
root@webscalesql-5.6.clean:[Mon Mar 31 11:37:15][/opt]$ mkdir installs
root@webscalesql-5.6.clean:[Mon Mar 31 11:37:17][/opt]$ cd installs/
root@webscalesql-5.6.clean:[Mon Mar 31 11:37:19][/opt/installs]$ git clone https://github.com/webscalesql/webscalesql-5.6.git
Initialized empty Git repository in /opt/installs/webscalesql-5.6/.git/
remote: Counting objects: 30397, done.
remote: Compressing objects: 100% (12678/12678), done.
remote: Total 30397 (delta 18716), reused 27620 (delta 16936)
Receiving objects: 100% (30397/30397), 47.99 MiB | 460 KiB/s, done.
Resolving deltas: 100% (18716/18716), done.

2. …

Best MariaDB ever hits the streets – MariaDB 10 innovations developed with Google, SkySQL & Fusion-IO

London, United Kingdom – 31 March 2014 – The MariaDB Foundation, an independent body which promotes the popular open source database MariaDB, today announced the much-anticipated general availability of MariaDB 10, providing today’s generation of application developers with enhanced performance and functionality.

Since its launch in 2009, MariaDB has built an active and vibrant open source community and has led the way in database innovation. In 2013, Wikimedia Foundation, the people behind Wikipedia, announced the migration of many of its production MySQL systems over to MariaDB and Google confirmed it aims to move its thousand-plus MySQL instances over to MariaDB technology.

Engineered by some of the world’s leading database experts, including MySQL founder, Michael ‘Monty’ …

March 27, 2014 By Severalnines

With datacenters being stretched by resource-intensive applications, more and more businesses are outgrowing their existing in-house capacity and having to reconfigure their IT operations. But how do you migrate a busy application to a totally new data center without downtime? How will the application scale in a virtualized cloud environment? And how do you guard against cloud server failures and keep a high level of uptime?

In this example, we will show you how to migrate a Web application (Wordpress) from a local data center to a AWS VPC. Without downtime even! 

Main steps:

• Setup the cloud servers (for web server + database)
• Install Galera Cluster and ClusterControl
• Setup MySQL replication between the single instance MySQL (local) to Galera Cluster (remote)
• Sync your application …

We deploy Galera Cluster (in MariaDB) for some clients, and innodb_flush_logs_on_trx_commit is one of the settings we’ve been playing with. The options according to the manual:

• =0 don’t write or flush at commit, write and flush once per second
• =1 write and flush at trx commit
• =2 write log, but only flush once per second

The flush (fsync) refers to the mechanism the filesystem uses to try and guarantee that written data is actually on the physical medium/device and not just in a buffer (of course cached RAID controllers, SANs and other devices use some different logic there, but it’s definitely written beyond the OS space).

In a non-cluster setup, you’d always want it to be =1 in order to be ACID compliant and that’s also InnoDB’s default. So far so good. For cluster setups, you could be more lenient with this as you require ACID on the cluster as …

MariaDB 10 is nearing GA, and it makes sense to make sure that the test suite from MySQL 5.6 is merged into MariaDB 10. Svoj is doing a lot of this work, and then we like to look at features, especially ones that are deprecated upstream. We don’t do that on blogs, but on the maria-developers mailing list.

I bring to your attention: Intermediate status for test cases merge. We see that INSERT DELAYED and SHOW PROFILE for example are deprecated in MySQL 5.6. The only way for feedback to the MySQL team seems to be comments on Morgan’s blog. However with MariaDB, especially with the feedback plugin enabled, we have an additional layer of …

I needed to test the new server audit plug-in on latest MariaDB 10.0.9
More info about that handy plug in you may find here : http://www.skysql.com/downloads/mariadb-audit-plugin
Take a moment to read the info, along with that nice blog : http://www.skysql.com/blogs/ralf-gebhardt/activating-auditing-mariadb-and-mysql-5-minutes

In short:

root@mariadb-10.0.9:[Mon Mar 24 07:51:54][/tmp/]$ lftp http://ftp.igh.cnrs.fr/pub/mariadb/mariadb-10.0.9/yum/
cd ok, cwd=/pub/mariadb/mariadb-10.0.9/yum                                   
lftp ftp.igh.cnrs.fr:/pub/mariadb/mariadb-10.0.9/yum> bookmark add mariadb-10.0.9
lftp ftp.igh.cnrs.fr:/pub/mariadb/mariadb-10.0.9/yum> ls
drwxr-xr-x  --  ..                   
drwxr-xr-x            - …

Background

Eventual consistency is a consistency model used in many large distributed databases which requires that all changes to a replicated piece of data eventually reach all affected replicas; conflict resolution is not handled and responsibility is pushed up to the application author in the event of conflicting updates [13].

Eventual consistency is a specific form of weak consistency; the storage system guarantees that if no new updates are made to the object, eventually all accesses will return the last updated value [14]. If no failures occur, the maximum size of the inconsistency window can be determined based on factors such as communication delays, the load on the system, and the number of replicas involved in the replication scheme [3].

A few examples of eventually consistent systems:

• DNS
• Asynchronous master/slave replication on an RDBMS e.g. MariaDB
• memcached in front …

March 20, 2014 By Severalnines

SugarCRM is the leader in open source CRM systems, and has been adopted by some of the largest firms, including IBM. The CRM software includes all sales, marketing and support tools out of the box, and can also be extended to integrate social media sources. For those depending on SugarCRM, especially when deploying in cloud environments with lower SLAs, having a high availability architecture can make a lot of sense. 

In this blog post, we will show you how to cluster SugarCRM Community Edition with MySQL Galera Cluster. For simplicity, we will use NFS as the shared storage system (storage1) but keep in mind that storage1 is a single point of failure. Have a look at our previous blogs on how to deploy other shared file systems like …

A MariaDB Howto authored by: Erkan Yanar.

This is a Howto about installing MariaDB Galera Cluster on Debian/Ubuntu. Because a lot of people were having problems installing MariaDB Galera Cluster, elenst from #maria on freenode forced me to write this Howto

Installing MariaDB Galera Cluster is in fact quite easy and actually kind of boring in the end. This Howto is written for (and tested on) on Debian 7.1 (Wheezy) and Ubuntu 12.04 (Precise).

What we need

In our setup we assume 3 nodes (node01, node02, node03) with one interface each. We assume following IP addresses: 172.16.8.5, 172.16.8.6, and 172.16.8.4. We need three packages installed on all nodes:

• rsync
• galera
• mariadb-galera-server

As Galera does not ship with the distribution repositories, go for the …