I discovered while compiling Wafflegrid today that by default, the Ubuntu binaries for memcached are not-multithreaded.

Following the installation of memcached from apt-get and libmemcached I ran memslap for:

$ memslap -s localhost
    Threads connecting to servers 1
    Took 1.633 seconds to load data

$ memstat -s localhost
Listing 1 Server

Server: localhost (11211)
     pid: 23868
     uptime: 54
     time: 1244575816
     version: 1.2.2
     pointer_size: 32
     rusage_user: 0.90000
     rusage_system: 0.120000
     curr_items: 10000
     total_items: 10000
     bytes: 5430000
     curr_connections: 1
     total_connections: 3
     connection_structures: 2
     cmd_get: 0
     cmd_set: 10000
     get_hits: 0
     get_misses: 0 …

Seem’s the year Sun had for improving MySQL, and with an entire new 5.4 branch the development team could not fix the autoconf and compile dependencies that has been in MySQL for all the years I’ve been compiling MySQL. Drizzle has got it right, thanks to the great work of Monty Taylor.

I’m working on the Wafflegrid AWS EC2 AMI’s for Matt Yonkovit and while compiling 5.1 was straight forward under Ubuntu 8.10 Intrepid, compiling 5.4 was more complicated.

For MySQL 5.1 I needed only to do the following:

apt-get install -y build-essential
apt-get install libncurses5-dev
./configure
make
make install

For MySQL 5.4, I …

For any production MySQL Database system, running RAID is a given these days. Do you know what RAID your database is? Are you sure?. Ask for quantifiable reproducible output from your systems provider or your System Administrator.

As a consultant I don’t always know the specific tools for the clients deployed H/W, but I ask the question. On more the one occasion the actual result differed from the clients’ perspective or what they were told, and twice I’ve discovered that clients when asked if their RAID was running in a degraded mode, it actually was and they didn’t know.

You can read about various benchmarks at MySQL blogs such as BigDBAHead and MySQL Performance Blog however getting first hand experience of your actually RAID …

OSCON moves this year from Portland to San Jose.

As one the community panel for Drizzle: Status, Principles, and Ecosystem I also have a speaker discount which you can combine with O’Reilly having also extended early bird registration until June 23.

Be sure to add the os09fos code for an additional 20% off, and be sure to shout me a drink there.

If you had to configure a Wordpress MU installation without access to any details of your MySQL Configuration, what would you do?

What top five configuration settings would you use?

I asked the community this question, see For MySQL DBA fame and glory. Prize included and a number of brave soles responded for a chance to win a free copy of MySQL Administrators Bible by MySQL Community She-BA Sheeri Cabral.

There is no perfect answer and of course you would want to set more then five options, however the purpose of the competition was to seek what people would do with limited information and a limited choice of …

Update 8 June 2009
Be sure you to check out some of my research including Understanding your RAID Configuration and Understanding PERC RAID Controllers.

Last week I got caught thinking a MySQL production system wasn’t configured with RAID when it actually was. The following is the Linux dmesg output of 3 different client MySQL servers, where the H/W is all the same, a Dell 2950.

In the first two cases you will see individual references to the internal disks, however in the third you do not. This threw me, but as Matt Yonkovit correctly pointed out to me, the sizes are not standard drive sizes. …

Last week I posted the following twitter request — “Can somebody loan me (or buy me) a Dell 2950 decked out so I can run and publish some benchmarks. Please!”

In a same day response I was offered access to use 2 x Dell 1950’s, and today I’m now actually using these machines for my own testing. I would like to thank cafemom (Barry, Anthony & Dan) for the loan of hardware.

And now the chance to better understand the RAID configuration of the DELL PERC Controllers, trying out some different RAID types, LVM configurations and disk tests. When I’m done with my System Administrator refresher, I’m then be trying some different MySQL Benchmarks to test various MySQL configuration settings including using the new Juice …

I’ve decided to give people two more days for a chance to win a free MySQL Book — Sheeri Cabral’s MySQL Administrators Bible.

I have had five people so far provide recommendations for a simple MySQL configuration question as stated in For MySQL DBA fame and glory. Prize included. Shlomi Noach the current front runner.

Try your MySQL Performance Tuning skills. This is a good opportunity for new MySQL DBA’s and experienced DBA’s to provide basic input.

The reason for yesterday’s Basic OS/MySQL Security was a request to review a system and I was given the production server ‘root’ password in an email. Never email a ‘root’ password, especially including the hostname as well. Email is an insecure protocol that can be monitored by hackers. However, today’s basic security tip following a look at the system is:

Never store the MySQL ‘root’ user password in a ~root/.my.cnf file.

There is simply no reason to do so, and you expose your database to destruction or manipulation when a user has access to the ‘root’ OS user, for example via sudo.

I’ve heard excuses why the ‘root’ MySQL password has to be in a file, I’ve yet to be convinced.

Do you need to store a MySQL password in a file? Yes. Connection management for your application is an …

I came across the following configuration today on a Production MySQL system (5.0.67) running 30+ blogs using Wordpress MU.

$ cat /etc/my.cnf
[mysqld]
set-variable = max_connections=500
safe-show-database

No I did not truncate the output. I could say I’ve seen worse, but that’s a stretch.

So the quiz and a prize for the best response, for the next 48 hours I’ll accept your comments as responses to this post for the top 5 settings you would add, and additionally what information you may need to add these settings. Bonus points for giving a reason why you would add the settings as well.

For example, I’ll give you the most obvious.

key_buffer_size = ????

To determine a key_buffer_size to start with I would look at the size of all Indexes via I_S, and combine with some estimate of growth, say 2x-5x.

For the best answer …