Xaprb » humor

What are your favorite MySQL bug reports?

Xaprb — Mon, 23 Aug 2010 23:00:51 +0000

Bug reports can be fun. They can also be terrible. Either way they can be entertaining. On the Drizzle IRC channel today I saw a couple references to MySQL bug reports: it is stop working and Does not make toast (which reminds me of the Mozilla bug report about the kitchen sink). Got any other favourites¹?

¹ This one’s for Jay.

Further Reading:

My new mailing list policy

Xaprb — Thu, 06 May 2010 11:28:38 +0000

I think I’m going to adopt a policy of not replying to posts to mailing lists that end with blurbs such as the following.

The information contained in this mail is solely property of the sender’s organization. This mail communication is confidential. Recipients named above are obligated to maintain secrecy and are not permitted to disclose the contents of this communication to others. This email and any files transmitted with it are confidential and intended solely for the use of the individual or entity to whom they are addressed. If you have received this email in error please notify the originator of the message. Any views expressed in this message are those of the individual sender.

I can make the excuse that my lawyers won’t let me because they are trying to understand the legal ramifications of responding to a message on a public mailing list with a disclaimer like that. Nothing shorts out a lawyer’s circuits like trying to understand the risks of engaging with another person’s risky behavior after accepting a disclaimer about said behavior.

I wish someone could at least invent a shorter disclaimer. Seriously — wouldn’t a few words do just as well? How about this:

This email is confidential and proprietary. Do not disclose to third parties.

Or even better, how about this:

I’m a moron. Thank you for ignoring me.

Further Reading:

Breaking news: SHOW INNODB STATUS ported to XML

Xaprb — Tue, 20 Apr 2010 19:25:14 +0000

If you’re like me, you’ve gotten tired of writing endless test cases for parsers that can understand the thousands of variations of text output by SHOW INNODB STATUS. I’ve decided to solve this issue once and for all by patching MySQL and InnoDB to output XML, the universal markup format, so tools can understand and manipulate it easily. Here’s a sample snippet:

PS: Yes, this is a late April Fool’s joke.

Further Reading:

4 ways that instrumentation is like sex

Xaprb — Wed, 31 Mar 2010 03:57:36 +0000

In an application such as a database server, instrumentation is like sex: it’s not enough to know how often things happen. You also care about how long they took, and in many cases you want to know how big they were.

“Things” are the things you want to optimize. Want to optimize queries? Then you need to know what activities that query causes to happen. Most systems have at least some of this kind of instrumentation. If you look around at… let’s not pick on the usual targets… oh, say Sphinx, Redis, and memcached. What metrics do they provide? They provide counters that say how often various things happened. (Most of these systems provide very few and coarse-grained counters.) That’s not very helpful. So I read from disk N times, and I read from memory N times, and I compared rows N times… so what? I still don’t know anything relevant to execution time.

That’s why we need to measure how long things took. It’d be great if, for every Handler_X counter variable in MySQL’s SHOW STATUS, we also had a Handler_X_time in microseconds. True, better instrumentation could be designed, but that’d be a huge step forward already. Instead of guessing at the significance of Sort_rows, we could look at Sort_rows_time and see if a lot of time is being consumed sorting rows!.

Next, we need to know how big things are. This is a rather generic term, but in a lot of cases, the size, difficulty, or some other metric of an operation is important. “I wrote a message to the network socket” is okay; “I wrote and it took N microseconds” is better; and “I wrote N bytes and it consumed M microseconds” is best. Made a temp table on disk? Nice — how big was it? Mine’s smaller than yours!

The final way that instrumentation is like sex: more is better, to an extent. You can get too much, but how often has that happened to you?

Further Reading:

Vim versus Emacs

Xaprb — Tue, 02 Mar 2010 18:18:19 +0000

Which is better? I don’t know, because I’m a Vim user, so it’s a moot point for me. But I have not noticed any Emacs-style keyboard shortcuts on websites. To the contrary, it seems like everything is Vim-style — certainly most Google apps are Vim-ish, and even Firefox is Vim-ish (press the / key to start searching for text on the page). Based on this highly scientific criterion, I declare Vim the winner.

Further Reading: