MySQL is adding more tools to monitor its internals with every new release, but one thing it still lacks is a way to find out who is locking what, and therefore which transactions block which other ones. This is such a vital feature that I'm considering writing my own patch to the source! Still, it is possible, to a limited extent, to find out who's locking resources. In this article I'll explain how you can do that.

This article is the second in a series on how to use the innotop MySQL and InnoDB monitor.

I’ve made several improvements to the innotop InnoDB and MySQL monitor, and it’s ready to get from the innotop homepage. As usual, it’s a combination of bug fixes, new features, and enhancements to existing features. Changes since version 0.1.112 include More detailed lock information displayed in InnoDB Deadlock mode. A new section in Row Operations / Semaphores mode shows information about the wait array. I’ve expanded the test suite a lot.

For any DBA, broken replication represents a dreaded moment. Replication can break for many factors including when the master server issues a 'Duplicate entry' error. At that point you can either skip the slave counter (recommended) or ignore/skip the errors (slave-skip-errors=1062) if you are sure that ignoring such errors won't cause a nasty effect somewhere.

Depending on when you troubleshoot the situation, when replication resumes, slaves may fall significantly behind and the relay log files may start consuming huge amount of disk space. If you have ample free disk space then that is not an issue however, if you are tight on disk space then the relay-log-space-limit option can really come handy.

The relay-log-space-limit option limits the disk space used by the relay log files. You can specify the value in bytes, megabytes (10000M) …

A while ago I wrote a tutorial on the MySQL Sandbox.
Wallace Reis asked me permission to translate it, and I happily agreed.
And now there it is: the tutorial Portuguese translation (the first part, but the rest will come).
Thanks, Wallace!

OK, thanks for good comments from the MySQL Build Farm Part 1 post. I have gone ahead and created a new page, called MySQL Build Farm Initiative. This is intended to be the whiteboard and discussion area for the community to contribute ideas during this initial phase of the project. I have added Sebastian and Ronald's comments into this document. Feel free to add to the features list and add comments to the page.

I will be posting information later to the page based on my discussions with the build team about some of the internals of the build process. Hopefully this information can help others as we plan out the project.

Also, Marten, our …

By tim

There were a number of detailed blog entries covering some of the sessions from my O'Reilly Radar Executive Briefing at OSCON. I thought I'd point to them for the benefit of those who weren't there. On ZDNet, Russell Shaw covered Danese Cooper's interview with Bill Hilf of Microsoft, my conversation with Jim Buckmaster of Craigslist, and my conversation with Ian Wilkes of Second Life. In each case, he captured some good quotes. A sampling:

Bill: "We are dealing with close mindedness inside and outside..."

Ian: "I did a count recently, and over an entire cluster there are five million user processes going on at any given time. There's geographical mapping at the front end, but at the back end …

Ahhh, finally back from OSCON. There was a mixup with the hotel rooms and I accidentally did not get reservations for my last night in Portland (Saturday). I checked four hotels and they were all out of rooms, and I was a bit freaked out about the possibility of spending the night on a couch in a lobby at the airport or a hotel.

Luckily, Scott Mathews from Dice.com offered to let me sleep on the floor of his hotel room. Lucky for me, that is. Unlucky for Scott, who had a fairly severe allergic reaction to the small tumbleweed of cat hair that was attached to my luggage. Unfortunately for Scott, he didn't realize the situation until the morning, when it was too late to do something about it...

Oh, and then the train system broke down when a tram accidentally disconnected the power line on the steel bridge going into downtown, causing a domino-effect breakdown of the system. So, into a town car Scott and I went, and off to the …

I'm leaving MySQL starting 1st of August. This is surely not news for my collegues and friends who knew this is comming.

We're starting our own company which will provide MySQL Consulting services. We'll focus on MySQL Performance Optimization but will be able to help pretty much with all MySQL related issues. We can also act as your remote MySQL DBA or help you scaling your LAMP Application.

In addition to that I'll get back on Entrepreneurial track and work on few Web Projects. Some of you know before joining MySQL I was co-founder and CTO of well known Web Statistics company in Russia and I loved it a lot. I will keep you posted as soon as I have something to show.

I will continue being part of MySQL Community, hopefully getting even more time for this. I will update this blog, hang around on forum, speak on conference as well as work on …

It seems to be a good time for people with experience in managing MySQL servers or developing applications based on MySQL: our MySQL Jobs Forum has plenty of openings. So if you are a seasoned MySQL DBA or developer, make sure to check for opportunities there, if you are considering a career change.

In addition to a proven track record on your MySQL experience, being MySQL certified should give you an extra advantage when you apply. The good thing about this certification? You can study for the exam by taking training courses, or all by yourself. Once you feel ready for the exam, you can head to any of the more than 3,000 …

In 4.0 the default character set is latin1. When converting to 4.1 this relationship is preserved. In many cases as in the case at flickr.com we store utf8 data in latin1 columns. So, think of the situation as latin1 being the container for utf8. This screws up a lot of thing especially when Java is used. We have to hack the driver to tell it even though the server is returning the data is latin1 it's really UTF8.


So, what is a good way to convert to true utf8 character set with a unicode collation.

Rebuild the data! This is the way that I'm doing it to also shrink the innodb datafile. There is a lot of free space.

Now remember we have utf8 data in a latin1 container column, so we need to make sure that we get a dump of the raw data. MySQL will double pad the data with default options converting the latin1 charset to utf8, which is garbage.

mysqldump -hHOST -uroot -p DB TABLE …