Moving into the user sessions on the first day at MySQL Conference 2007, I attended Building a Vertical Search Engine in a Day . Some of my notes for reference.

Listening to Elliott White III (Eli) and Tim Ellis (Time) talk about technology at the 2007 MySQL Conference. As expected, a packed session.

Eli is the Senior PHP dude, Time is the DBA.

Initially started with Apache 1.3 and PHP 4.x. Used MyIsam and MySQL full text search. Then moved to multiple servers, Apache 2.x, MySQL Innodb, PHP 5, and memcached. Are now using Lucene with solar for search. Currently around 100 machines, 30 databases and the rest serve other functions. 9 memcached machines running on the db slaves. Right now around 30 gigs of data. XSF for user interface stuff (millions of user images). ext3 for other things.

Many PHP servers behind a load balancer. Many MySQL slaves talking to a master. Randomize connections between PHP servers to MySQL connections.

Memcached is used heavily for caching chunks of content. You can't cache the entire page because it almost entirely customized for the user. …

This week I'm attending the second of two developer conferences on my schedule for this month. I noticed an interesting trend that I hadn't seen discussed anywhere else before. Nearly every presenter is using some kind of virtualization technology to give their talks.

This is a terrific idea -- it's awesome to have a more or less pristine copy of your development environment that you can put into cold storage and spin up right before your talk is slated to begin.

I'm not sure why it's taken until 2007 for this kind of virtualization to reach a tipping point, although it might have something to do with the success of Parallels on the Mac -- as well as the fact that Microsoft released Virtual PC as a free product last year. (Although I should mention that I overheard more than one conversation at VSLive two weeks ago from presenters who were slagging Virtual PC's performance.)

I'd be willing to bet that this trend will work …

Our third keynote at MySQL Conference 2007 was titled Building the Ultimate Database Container with RHEL, MySQL, and Virtualization by Michael Evans.

The presentation was on Red Hat & One Laptop Per Child. His initial Quote was “Thinking Past Platforms: The Next Challenge for Linux”, By Doc Sears, 2007-04-16 http://www.linuxjournal.com/node/1000210

OLPC

• A Non profit idea from Nicholas Negroponte.
• Aim is to build & distribute inexpensive laptop systems to primary & secondary school students worldwide.
• Sell to young children in developing countries.

In summary at presentation to Red Hat — “Non-profit, run by a professor, we make hardware and …

Our third keynote at MySQL Conference 2007 was titled Building the Ultimate Database Container with RHEL, MySQL, and Virtualization by Michael Evans. The presentation was on Red Hat & One Laptop Per Child.

Another great keynote at the 2007 MySQL User Conference is Michael Evans form RedHat talking about the One Laptop Per Child project. Pretty incredible the things they are doing.

Michael makes a lot of great points, I think this video sums it up nicely:

I get this question a lot. Why does a slave report that it's trying to replicate from an impossible position? 9 times out of 10 it's because the master crashed and when it came back online a new binlog file was made.

mySQL caches binlog events in the binlog cache, basically events are stored in memory and flushed to disk when the dirty buffer fills up. I believe the variable is called binlog_cache_size.

Here are some steps to recover from this:
Go onto the master execute

SHOW MASTER STATUS

Look at the output and find the log that the slave is pointing to. Look at the File size field.


Next look at the slave output from the slave reporting the issue. Look at Exec_Master_Log_Pos, is that value greater then the File Size on the master if so issue


CHANGE MASTER TO MASTER_LOG_FILE=[NEXT FILE], MASTER_LOG_POS=4;
slave start;
…

Without missing a beat at MySQL Conference 2007, we moved from Marten’s keynote to The Art of Innovation by Guy Kawasaki.

Extremely fun and entertaining. His 10 points.

1. Make Meaning

• “To change the world”
• To a VC, do not say “you want to make money”, that is understood. You will attract the wrong team.

2. Make Mantra

• Not a Mission statement (50-60 words long), but 2 or 3 words.
  • Wendy’s - “Healthy fast food”
  • Mike - “Authentic Athletic Performance”
  • FedEx - “Peace of Mind”
  • eBay - “Democratize commerce”
• Create a mantra — Why do you exist?

If you get stuck try the …

Without missing a beat at MySQL Conference 2007, we moved from Marten’s keynote to The Art of Innovation by Guy Kawasaki. Extremely fun and entertaining. His 10 points. 1. Make Meaning

As I mentioned in MySQL Conference – Rewarding the Community , Paul McCullagh, the creator of the Community Transactional Storage Engine PBXT won the Community Code Contributor of the Year award.