Bug fixes:
* In some situations where SSH connections failed (including if MONyog was not able to connect to MySQL, wrong SSH authentication details for tunnelling etc.), sockets were not being closed and it could result in that many sockets were kept in CLOSE_WAIT state. (note: connections to MySQL not using SSH were not affected!)

Downloads: http://webyog.com/en/downloads.php
Purchase: http://webyog.com/en/buy.php

Referred to by Launchpad Bug #119271 and MySQL Bug#28850, MySQL installations get bitten after an upgrade, if they were acting as a replication slave. However, the actually root cause is not an upgrade.

If you simply set up say Ubuntu Feisty, you'll encounter the same problem. If you set up as a slave, the server uses a relay log. In the affected versions, its put under /var/run. That's a serious snafu, because /var/run is generally on tmpfs and a) very small, and b) gets wiped on a restart. Only runtime foo like .pid files should be under /var/run (as per LSB, Linux Standards Base).
Anyway, the "gets wiped on restart" is where new installations get bitten, although the error is of course the same as on an upgrade where the path changes from /var/lib/mysql: the …

I have been using Maatkit in a different way since I joined Percona as a consultant. When I’m working on a system now, it’s a new, unfamiliar system — not one where I have already installed my favorite programs. And that means I want to grab my favorite productivity tools fast.

I intentionally wrote the Maatkit tools so they don’t need to be “installed.” You just run them, that’s all. But I never made them easy to download.

I fixed that. Now, at the command line, you can just run this:

wget http://www.maatkit.org/get/mk-table-sync

Now it’s ready to run. Behind the scenes are some Apache mod_rewrite rules, a Perl script or two, and Subversion. When you do this, you’re getting the latest code from Subversion’s trunk.[1][2] (I like to run on the bleeding edge. Releases are for people who want …

A while ago I wrote about native MySQL connectivy for OpenOffice.org which Georg Richter had spent a lot of time on, but which then got stuck in some licensing foo. That blog entry generated a number of responses from former MySQL colleagues, noting that something was in the works. A bit later Georg himself commented:Arjen,

sorry, but I didn't find the time to blog about - I had to write some code :-)

The license of the code will be LGPL 3.0 (like OpenOffice) - it still uses libmysql. The code will be available via cvs.openoffice.org pretty soon.

If you're interested in testing some binaries, check out the new preview version at http://forge.mysql.com/wiki/Connector_OpenOffice

/GeorgSo that's cool, and everybody please do check it …

One of the comments to last week's scribble on joins referred to the POSIX join command. What does this mean? There is a commandline tool called 'join' available on most Unix-ish boxes, including Linux and OS X. From my own Mac ("man 1 join"):NAME
join -- relational database operator

SYNOPSIS
join [-a file_number | -v file_number] [-e string] [-o list] [-t char]
[-1 field] [-2 field] file1 file2The commenter also mentions this article which explores the command some more with examples.

It's not MySQL, but it looks very useful. Not all data should be in a db, sometimes a textfile is perfectly sensible, and sometimes you just …

Sam Varghese of iTWire invited me for a broad interview when I was teaching in Melbourne last week, it's now published (MySQL: the Australian connection).

I just got around to reading Stephen O’Grady’s post on the relative openness of open source vendors and realized I had failed to be as clear as I could have been in my original post on the subject.

Responding to my note about Milking the GNU’s suggestion that a new independent organization could be formed to judge vendors on their level of openness, Stephen wrote:

“Those in the industry that might care have, I would argue, already formed their opinions on whether or not a project such as MySQL?s is or is not open source. And those outside the industry, well, I don?t expect they?d care. At all. Most of the enterprises I speak with are …

Marten Mickos will visit Rome on May 30th. He will meet the press and customers in the morning, and will be the main guest at a conference hosted at La Sapienza, Rome well known University.

Innotop is a very useful tool to monitor innodb information in real time. This tool is written by Baron Schwartz who is also an author of “High Performance MySQL, Second edition” book. [Side note: I highly recommend getting this book when it comes out (in June, 08?). Other authors include: Peter Zaitsev, Jeremy Zawodny, Arjen Lentz, Vadim Tkachenko and Derek J. Balling.] Quick summary of what innotop can monitor (from: http://innotop.sourceforge.net/): InnoDB transactions and internals, queries and processes, deadlocks, foreign key errors, replication status, system variables and status and much more.

Following are the instructions on how to install innotop on CentOS x64/Fedora/RHEL (Redhat enterprise). Most probably same instructions can be used on all flavors of Linux. If not, leave me a comment and I will research a solution for you. Let us start with downloading innotop. I used version 1.6.0 which is the latest at the time of …

I always use to blog my temporary ideas on one of my Japanese blog (id:kazuhooku's memos). When I wrote my thoughts on how to further optimize Q4M, Nishida-san asked me "how fast is the raw performance without client overhead?" Although it seems a bit diffcult to answer directly, it is easy to measure the performance of MySQL core and the storage engine interface, and by deducting the overhead, the raw performance of I/O operations in Q4M can be estimated. All the benchmarks were taken on linux 2.6.18 running on two Opteron 2218s.

So at first, I measured the raw performance of MySQL core on my testbed using mysqlslap, which was 115k queries per second.

$ perl -e 'print "select 1;\n" for 1..10000' > …