Archive for the ‘Geek’ Category
Default log file name changes and replication breakage.
In a Great Magnet moment Trent Lloyd posted an excellent write-up on how to recover from relay log name changes on the same day I was going to write up a procedure to send to a client who had a similar issue. Thanks Trent! The problem goes a bit deeper than server hostname changes because [...]
cinfo for seeing how much of a file is being cached
cinfo is a kick ass program written by the author of PowerDNS Bert Hubert to show how much of a file is being cached by the operating system. It’s great for testing to see if myisam data files are being read from the operating system cache or off disk. For example this is the cache [...]
Load average
Modern operating systems give the impression of running more processes than the number of available processors by giving each process that wants to run, such as your web browser or text editor a tiny slice of time in which they can execute. By switching out the running process very quickly it looks as though all [...]
fadvise syscall, myisam data file caching, and a lesson learned in debugging
fadvise is a system call that can be used to give Linux hints about how it should be caching files. It has a few options for caching, not caching, read ahead, and random access. I was looking into used fadvise because a client ran into an issue where some infrequently used myisam data files were [...]
Using vim as a man page viewer
I love color on my terminal. Black and white editors and and man pages are boring and more difficult to read than simple syntax highlighting. Vim supports syntax highlighting for man pages. Using it is as simple as setting an environment variable. MANPAGER=”col -b | vim -c ‘set ft=man nomod nolist’ -” You can add [...]
Why Oracle can’t kill MySQL.
When Oracle agreed to acquire Sun there was some speculation that Oracle might try to kill MySQL. First this wouldn’t be a very prudent effort on Oracle’s part and second it’s not even possible. I think Monty has the best explanation from his comment on his blog: The simple fact is one can’t own an [...]
Update of Google’s Sysbench patch to 0.4.12
[Update: I found the magic javascript links that show old releases of sysbench.] Sysbench is an application that can be used to benchmark different system parameters and also includes support for testing MySQL directly. Google has released a patch for sysbench that adds a lot of new OLTP tests. It’s great for testing MySQL and [...]
Percona Performance Conference EMT Presentation Slides
I sat down about 20 minutes ago to write a blog post that included a link to the slides of my EMT presentation. It turned into a long post about the presentation, how I feel EMT was received and my feelings on presentations in general. Here is the short post and the link to the [...]
MySQL Brings the Heat
This week throngs of MySQL developers, users, and enthusiasts descended on silicon valley. Apparently the valley’s cooling system can’t keep up because as they arrived the outside temperature went up into the 90s (32s for those of you who choose to use a sane temperature measurement system). I’m not attending the conference this year but [...]
Longest beta ever, myisamchk –parallel-recover
I was reading through the manual and noticed that myisamchk parallel recover option is still listed as beta code. The feature was added in 4.0.2 which was released in july 2002. This means it’s been in beta longer than gmail