Measuring how well a MySQL is doing can be tough – most metrics are simply proxies for actual performance. Thankfully, the Percona build of MySQL allows you to see exactly how long your queries are taking. It provides a diagnostic view that shows how long queries take, allowing you to gauge its real-world performance. I’ll get to that in a little bit. Before we do that, I want to talk about some other tools you can use.

You can dump the status of the system by running “show global status;”. This will give you how many connections have aborted, rows written, and how long the server has been up. This is historical info that’s erased when you flush it or when the server restarts (planned or unplanned). By sampling at regular intervals, you can also build monitoring scripts that measure changes over time …

To expand on Jervin’s Default RDS Account Privileges, RDS for MySQL provides a number of routines and triggers defined the the ‘mysql’ meta schema. These help in various tasks because the SUPER privilege is not provided.

SELECT routine_schema,routine_name
FROM information_schema.routines;
+----------------+-----------------------------------+
| routine_schema | routine_name                      |
+----------------+-----------------------------------+
| mysql          | rds_collect_global_status_history |
| mysql          | rds_disable_gsh_collector         |
| mysql          | rds_disable_gsh_rotation          |
| mysql          | rds_enable_gsh_collector          |
| mysql          | rds_enable_gsh_rotation           |
| mysql          | rds_kill                          |
| mysql          | rds_kill_query                    |
| mysql          | …

Help, the database is on fire. Well, it probably is but the solution may also be easy. Here are a few steps for the part-time MySQL DBA/sysadmin/developer. Total time to address this solution was 2 minutes, the inability to not go back to sleep, not priceless.

First, access to the DB server is possible, and also the mysql command line client. If you are getting “Too Many Connections” read Why GRANT ALL is bad.

Given the message “the database is on fire”, the likely cause is rogue SQL.

mysql> show global variables like 'max_connections';
+-----------------+-------+
| Variable_name   | Value |
+-----------------+-------+
| max_connections | 5000  |
+-----------------+-------+
1 row in set (0.02 sec)

mysql> show global status like 'threads%';
+-------------------+-------+
| Variable_name     | Value | …

and the video can be directly played in your browser at http://technocation.org/node/697/play or downloaded (170Mb) at http://technocation.org/node/697/download.

and the video can be directly played in your browser at http://technocation.org/node/697/play or downloaded (170Mb) at http://technocation.org/node/697/download.

I do not recall seeing an announcement about it, pancreatitis but I went looking for the videos today and lo and behold, they were up! Forgive me if I missed a post about it….but if you also missed it, here they are:

<A …

I’ve just had a new article published with the Software Developers Journal talking about how you can write applications to take full advantage of Continuent Tungsten and Tungsten Replicator.

As a developer of an application there really isn’t a problem better than finding that you have to scale up the application and the database that supports it to handle the increased load. The main bottleneck to most expansion is the database server and in many modern environments that replication is based around MySQL. Application servers are easy to add on to the front-end of your environment.

Read: Qt5 – How to Become a Professional Developer- RELEASED | News | Magazine for software developers, programmers and designers – …

It can be hard for software engineers to understand the following principle, however it is very important for improving performance and obtaining immediate scalability options. The principle is “Do Less Work”. That is, run less SQL statements.

Just one method to achieving the execution of less SQL statements is to eliminate Row At a Time (RAT) processing. In simple terms, do not perform identical repeating SQL statements in a loop. Relational algebra, and the Structure Query Language (SQL) specification is specifically designed to work with sets of data, or as I describe, Chunk At a Time (CAT) processing.

Customer Example

Your online social media website lets you send messages to multiple friends at one time. You enter the message, select the friends you want to receive the message and click send. While the user waits a moment and gets a success message, behind the scenes the application runs the …

What if the data you retrieved from the database did not match the data the application claimed to had successfully stored? How comfortable would your organization feel about your skills and the products that are being used to store important information if data integrity was not guaranteed?

MySQL employs a terrible default technique known as silent truncation where the product determines that it knows about your data better than you. Never has the saying “do not assume” because it makes an “ass” out of “u” and “me” been more applicable.

Customer Example

A HTML form for new customers provide input fields for the customer first and last name. Good design was considered with the HTML form client validation to ensure that each field could not exceed 20 characters in length. However, the database design is different, where the first name is only defined as 10 characters. In most cases this is sufficient, …

Today, just like many times before, I needed to configure a monitoring server for MySQL using Cacti and awesome Percona Monitoring Templates. The only difference was that this time I wanted to get it to run with 1 min resolution (using ganglia and graphite, both with 10 sec resolution, for all the rest of our monitoring in Swiftype really spoiled me!). And that’s where the usual pain in the ass Cacti configuration gets really amplified by the million things you need to change to make it work. So, this is a short checklist post for those who need to configure a Cacti server with 1 minute resolution and setup Percona Monitoring Plugins on it.

Configuring Cacti for 60-seconds polling

First of all, we need to take a Cacti server, which by default is configured to do polling …

My MySQL bugs is a list I recently created and intend to keep up to date with issues I have seen.

As mentioned here and after talking to a few people we have created a meetup page, http://www.meetup.com/Madrid-MySQL-users-group/ and proposed the first meeting on Thursday, 4th July. If you are interested and in the area come along and say hello. It should be interesting to see a few others who work in the field.  If you can let us know you are coming so we have an idea of how much interest there is.