Replication is the process that transfers data from an active master to a slave server, which reproduces the data stream to achieve, as best as possible, a faithful copy of the data in the master.

To check replication health, you may start with sampling the service, i.e. committing some Sentinel value in the master and retrieving it from the slave.

Sentinel data: Tap tap… Is this thing on?
If you want to make sure that replication is working, the easiest test is using replication itself to see if data is being copied across from the master to the slaves. The method is easy:

1. Make sure that the data you want to see is NOT in the master or in the slave. If you skip this step, you may think that replication is working, while in fact it may not.
2. Either create a table …

There is an error which is definitely new to people which have encountered such situation at first time.
It was reported a long time before:
#1689 -> 28 Oct 2003 4:46
#1478 -> 4 Oct 2003 10:58
#7501 -> 23 Dec 2004 5:35

Error is -> ERROR 1054 (42S22): Unknown column ‘c2’ in ‘field list’
The Place where you can encounter this error is something similar below:

mysql> show create table t1;
| t1    | CREATE TABLE `t1` (
  `id` int(11) DEFAULT NULL,
  `c1` varchar(85) DEFAULT NULL
) /*!50100 TABLESPACE innodb_file_per_table */ ENGINE=InnoDB DEFAULT CHARSET=utf8 |

If you try to insert …

Hi Julien
Thanks. As Enterprise Monitor is one of the commercial tools, previous versions can be downloaded from support.oracle.com under the Patches tab. Remember, as part of the Enterprise Edition, you’ll need a valid Support contract.
Hope this helps.
rgds
K.

Thanks a lot for this post.

Unfortunately, i can’t find mysqlmonitoragent v2.3 anymore.

Do you know where i can find it?

Lately I saw many cases when users specified option

--base64-output=DECODE-ROWS

  to print out a statement representation of row events in MySQL binary logs just to get nothing. Reason for this is obvious: option

--base64-output=DECODE-ROWS

  does not convert row events into its string representation, this is job of option

--verbose

. But why users mix these two options so often? This blog post is result of my investigations.

There are already two great blog posts about printing row events on the Percona blog: “Debugging problems with row based replication” by Justin Swanhart and “ …

Thanks to everyone who joined us yesterday for this live session on designing HA for MySQL led by Krzysztof Książek, Senior Support Engineer at Severalnines. The replay and slides to the webinar are now available to watch and read online via the links below.

Watch the replay:

Become a MySQL DBA - webinar series: Which High Availability solution? from Severalnines AB  

Read the slides:

Become a MySQL DBA - webinar series - slides: Which High Availability solution? from …

This post is likely gonna get less relevant when Magento 2 comes out, but I decided to put it out there any way. In my limited time working with Magento I’ve come across a couple scenario’s I wanted to touch on. Hope it’s helpful for anyone.

Let say a merchant wants a new Magento online store. Now, there are a couple scenario’s that are likely or less likely:

1. The previous store was built with Magento. Customers can easily be imported using the various tools available (Magmi, import/export, dataflow, etc.)
2. The previous store was built on a platform that stores passwords in plaintext - fortunately this is not very likely ;)
3. The previous store was built on a different platform, using different hashing algorithms.
4. The previous store was built on a different platform which happens to use the same hashing algorithm as Magento,
5. A combination of #3 and #4 (yes - I’ve seen it). …

Loading databases on virtual systems is not as straight forward as it should be. Last time the foundation for using Ansible was set down on our quest to be able to have fully functional database servers on virtual servers automatically. But that prompted a few of you to remind me that you do not always need Ansible.

Without Ansible
You can have Vagrant do the work. Modify the vagrant file to run a script to run a script when provisioned, such as
config.vm.provision :shell,path: "setup.sh"
and create the setup.sh shell script.

#!/bin/bash
#
# example setup script for LAMP stack on Vagant box
sudo apt-get -y update
sudo apt-get -y install apache2 php5 libapache2-mod-php5
## Set …

For every online business, there are millions of transactions happening every second including crucial revenue bearing transactions. Therefore downtime, both planned and unplanned has a cost attached to it and results in lost revenue every second. As the technology improved to meet this demand, the importance of High Availability (HA) became the focus point.

The introduction of Galera Cluster for MySQL bought true Multimaster Cluster thanks to its synchronous replication. In this article, we’ll show how using MONyog in tandem with Galera provides a simple and best-in-class High Availability solution for MySQL users.

How to register a Galera Cluster Node in MONyog

1. Enter the Hostname, port and credentials in “MySQL settings”, test the connection and save it.
2. Enable “Galera” group from “Customize” > “Manage monitor groups”
3. In Monitors page, select the “Galera” group and …

After several iterations and a long period of community evaluation, I am happy to report I've released the newest, stable release of the MySQL Connector/Arduino. This library is designed to allow you to connect your Arduino via an Ethernet or WiFi shield to a MySQL database server running on your network (or the Internet!).

New Documentation! Best of all, I've written a reference manual that includes examples of how to use the connector in a variety of ways. Included in the document are advice on how to write your sketches, troubleshooting tips, and a long FAQ compiled from the many questions from my blogs.

Changes The only code change in this release is to fix a defect when using the connector with the latest versions of MySQL.

Downloading the Connector To download the connector library and the new reference manual, visit …