If you’ve ever used non-opensource code, or applications that you don’t have complete control over, then you may have run into situations you need to alter data on a per-row basis but been unable to do so for lack of application SQL access. The solution to this type of problem is to use a MySQL TRIGGER, which allows us to execute arbitrary SQL commands when defined events occur. Why is this useful and how does it work? Well…

For example, I have a freeRADIUS server that uses MySQL as a backend for the user authentication, and one of my server applications (HostBill) provides a freeRADIUS plugin that allows my users to manage their RADIUS accounts; however the default freeRADIUS schema lacks a DATETIME column on the user table. When a user is created (INSERT) or has their password changed (UPDATE)

• Rich Mason's keynote on how to Deploy, Scale and Save with Linux, Virtualization and MySQL
• Keith Hollman on stage to discuss how to Embrace Database Diversity
• Mark Swarbrick's lecture on 

Woooo, just wrapped up another night of #DBHangOps, check out the video:

For those of you who aren’t familiar with this awesome series of videos, it’s a bi-weekly meeting of MySQL DBAs via a Google Hangout to simply talk about databases (specifically MySQL). The discussions range anywhere from silly stories to awesome learnings and even little gotchas to know about when working with MySQL operationally. If you’re interested in catching when the next #DBHangops will happen, check MySQL planet for a blog post about it, or check this twitter search.

We look forward to talking with you!

I write a fair number of scripts on this site and have posted a lot of code over the years. Generally if I am not pasting the code to be viewed on the webpage then I link to a file that a user can download; which leads to a lot of mish-mash code that doesn’t have a home. I’ve always kept the code files in a private SVN repo over the years but have recently moved them all to BitBucket Git repositories. So here they are: lots of code samples and useful bits of programming to save time.

Generic Shell Scripts: https://bitbucket.org/themattreid/generic-bash-scripts/src
Generic Python Scripts: https://bitbucket.org/themattreid/generic-python-scripts/src
Generic MySQL Stored Procs:

This Week in Website Performance is a weekly feature of the Monitis.com blog. It summarizes recent articles about website performance. Why? Because your friends at Monitis.com care.

NoSQL or Traditional Database: From an APM Perspective There Isn’t Really Much Difference

Author: Michael Kopp.

If your application is executing more statements or downloading more data than is necessary, no amount of backend tuning will have your site running at the highest level of

I was digging through some old project code and found this script. Sometimes one finds oneself in an odd situation and needs to convert regular SQL, say from a MySQL database dump, into SQLite3 format. There’s not too much else to say, but here is a script that helps with the process. It can likely be improved but this handles the items that came up during conversion on initial runs.

#!/bin/sh
####
# NAME: convert-mysql-to-sqlite3.sh
# AUTHOR: Matt Reid
# DATE: 2011-03-22
# LICENSE: BSD
####
if [ "x$1" == "x" ]; then
   echo "Usage: $0 "
   exit 
fi 
cat $1 |
grep -v ' KEY "' |   
grep -v ' UNIQUE KEY "' |
grep -v ' PRIMARY KEY ' |
sed '/^SET/d' |          
sed 's/ unsigned / /g' | 
sed 's/ auto_increment/ primary key autoincrement/g' |
sed 's/ smallint([0-9]*) / integer /g' | 
sed 's/ tinyint([0-9]*) / integer /g' |  
sed 's/ int([0-9]*) / integer /g' |      
sed 's/

Read the original article at 10 ways I avoid trouble in database operations

1. Avoid destructive commands From time to time I’m working with new recruits and bringing them up to speed in operations. The first thing I emphasize is care with destructive commands. What do I mean here? Well there are all sorts of them. SQL commands such as DROP table & DROP database. But also TRUNCATE [...]

For more articles like these go to Sean Hull's Scalable Startups

After a long pause in the speaking game, I am back.

It's since April that I haven't been on stage, and it is now time to resume my public duties.

• I will speak at MySQL Connect in San Francisco, just at the start of Oracle Open World, with a talk on MySQL High Availability: Power and Usability. It is about the cool technology that is keeping me busy here at Continuent, which can make life really easy for DBAs. This talk will be a demo fest. If you are attending MySQL Connect, you should see it!
• A happy return for me. On October 27th I will talk about open source databases and the pleasures of command line operations at

If you’ve ever been troubleshooting on the MySQL command line and needed to quickly see how much memory is being used then you’ve probably noticed that there are no built in commands to give you this data. Unlike other enterprise databases MySQL doesn’t have a very robust management system built in to help make the DBA’s life easier. It doesn’t come with built in Stored Procedures to report on usage statistics or generate handy reports; so we have to code them and import them to MySQL — no relying on Oracle to help us out here.

So, here’s a stored procedure that can be imported to MySQL and run whenever you need to see the memory usage statistics. Installation and usage info is built into the SP below. The SP can also be downloaded from the repo:

I don't know why SELinux problems seem so frustrating. The problem almost certainly is related to the fact that there is frequently no error message. This is exactly the problem I ran into while turning up a new Apache web server on Red Hat Enterprise Linux 6 (RHEL6) with SELinux enabled.

The problem is that SELinux prevents Apache from making network connections by default. This is defined by the SELinux boolean httpd_can_network_connect_db. In order to change this value, issue the following

Based on my last post MySQL LDAP Authentication Plugin, I received feedback from MySql Joro Blog by Oracle.

They told me:

Insted of writing (and having to deply) your own client plugin you probably can reuse the cleartext client side plugin, specially because it’s available in a number of mysql clients already. Check sql-common/client.c on MySQL 5.5+ for details.

This is very useful because you only need to put the plugin in server side, and in the client side you only need to check if the clear password plugin is enabled.

Now, I present the updated code with the only server side plugin, and I reused the cleartext client side plugin from MySql, it’s more short

As a continuation of previous post, now, I will show how to make a mysql plugin for ldap authentication.

Get the mysql-server source code at http://dev.mysql.com/downloads/mysql/ (http://dev.mysql.com/get/Downloads/MySQL-5.5/mysql-5.5.27.tar.gz/from/http://cdn.mysql.com/)

Installing necessary packages

yum groupinstall 'Development Tools'
yum install cmake ncurses-devel

Download source code, build and start MySQL Server

wget http://dev.mysql.com/get/Downloads/MySQL-5.5/mysql-5.5.27.tar.gz/from/http://cdn.mysql.com/
tar -xzf mysql-5.5.27.tar.gz
cd mysql-5.5.25

# Preconfiguration setup
groupadd mysql
useradd -r -g mysql mysql

# Beginning of source-build specific instructions
cmake .
make
make install

# Postinstallation setup
chown -R mysql .
chgrp -R mysql .
./scripts/mysql_install_db

I have the goal of authenticate MySQL users with an LDAP server, currently, employees of my company are authenticated in several services (ftp, ssh, svn) through my LDAP server, except MySQL. (As you can imagine, I need to add manually every user in MySQL, a very tedious task).

In this post I only leave the example with LDAP authentication.

Installing necessary packages

yum groupinstall 'Development Tools'
yum install openldap-devel

Source ldapClient.c

#include <stdio.h>
#include <ldap.h>
/* LDAP Server settings */
#define LDAP_SERVER "ldap://nafiux.com:389"
int
main( int argc, char **argv )
{
LDAP        *ld;
int        rc;
char        bind_dn[100];

/* Get username and password */
if( argc != 3 )
{
perror( "invalid

I feel a sense of pride when I think that I was involved in the development and maintenance of what was probably the first piece of software accepted into Debian which then had and still has direct up-stream support from Microsoft. The world is a better place for having Microsoft in it. The first operating system I ever ran on an 08086-based CPU was MS-DOS 2.x. I remember how thrilled I was when we got to see how my friend’s 80286 system ran BBS software that would cause a modem to dial a local system and display the application as if it were running on a local machine. Totally sweet.

When we were living at 6162 NE Middle in the nine-eight 292, we got an 80386 which ran Doom. Yeah, the original one, not the fancy new one with the double barrel shotgun, but it would probably run that one, too.

The brief outage was due to a scheduled move of the servers to a separate rack and subnet dedicated to our work with the Center for Information Assurance & Cybersecurity (ciac) at the University of Washington Bothell (uwb), and a11y.com

I am currently exercising the new (to us) equipment and hope to winnow the less than awesome equipment over the next quarter. I spent the last six months finding the best in breed of the surplussed DL385 and DL380 chassis we (work) were going to have recycled. The team and I were able to find enough equipment to bring up one of each with eight and six gigs of memory, respectively. These will make excellent hypervisors for provisioning embedded instances of Slackware, Fedora, RHEL, CentOS, Debian, FreeBSD, OpenSolaris, OpenIndiana, FreeDOS, etc.

When I initially configured this xen paravirt environment, I failed to plan for integration with libvirt, so I am

This past week I attended OSCon, the annual conference for open source’s true believers. And there was a religous fervor in the air, particularly from the point of view of someone more accustomed to Oracle conferences.

And if open source is the religion, proprietary closed-source companies are the devil. That having been said, I was surprised how virtually all large companies were demonized. Even long-time defenders of open source like IBM were ignored at best. That didn’t prevent the from coming though, with Microsoft and HP in particular with high-profile sponsorships and PR offensives that didn’t seem to have much influence with the crowd.

The companies generating buzz were the small companies built around development of their own open source products. There are a surprising number of them out

A couple students in one of my classes ran into a problem when competing Java threads tried to insert new rows in a table. They raised an error when they tried the DELAY keyword to avoid the race (collision) condition in an INSERT statement. It was simple to explain to them that the DELAY keyword doesn’t work with an InnoDB table. Any attempt throws the following error:

ERROR 1616 (HY000): DELAYED OPTION NOT supported FOR TABLE 'message'

Important Update: INSERT DELAYED is gone in MySQL 5.6.6 (announcement) and the whole issue comes down to synchronizing threads (some dislike the solution) or using the ON DUPLICATE KEY

Converting from uw-mailboxes (mbx) to Unix format (dovecot)

It took me by surprise how the mailbox formats had changed, when I switched to Dovecot which is the best IMAP/POP3 mail program, in my opinion. It handles large (enormous) mailboxes with many (hundreds of) users. Caching makes things go fast again.

Here is a simple bash utility, to take all users, and convert all mailboxes & folders.

cd /home
for u in *
do
if [ -d /home/$u/Mail ]; then
echo "User: $u"
cd /home/$u/Mail

read more

On Linux, you have a plethora of File Systems available.

Recently I was testing databases (MySQL, MariaDB) especially with ThreadPool against a Violin Flash Memory Array, and I forgot what file system the LUN was mounted (and formatted) as.

There are two ways to find out:

• df -T (show mounted life systems, along with the FS type)
• file -s /dev/xxx (show more details about a FS node)

read more

I’m leaving myself some room for bug fixes. It works for us in house. I would love to help others to give it a try. especially those who could benefit from making nearly immediately answered queries to the NIST’s NVD database.

The code in this release cannot by itself track the feed from the feds in real time. The nvd entry loader needs a little bit of love in the area of record merging before this starts working. It’s on my TODO list.

I’m sorry for the outage of git.colliertech.org. I’ll get that back up here shortly. In the meantime, feel free to grab it from this location while the CPAN indexes and processes my submission.

http://www.colliertech.org/federal/NIST/NIST-NVD-1.00.00.tar.bz2

don’t forget to check the cryptographic signature: