One thing I did today was set up DNS for a hostname that we may needto re-point elsewhere very rapidly. This caused me to realize somethingimportant:

Setting low TTLs doesn't mean squat if you can't cause secondaries toreload on command.

Low TTLs mean that people will re-query A records frequently, but thatdoesn't help me change where the traffic is going if my secondarieshaven't updated to my new set of A records. Unfortunately, none of thesecondaries for

Every so often, I run into web design trends that I simply don'tunderstand. Since I've already grumbled about small font sizes , today's contestant is the mysterious case of thevanishing links.

Technically they haven't vanished. Instead they've carefully beengiven a colour that is almost exactly the same as the regular textcolour. Sometimes even exactly the same as the regular text colour.Ironically, in this situation the 'click here' style of link textactually becomes good, because

Most people will tell you that dynamic linking is an unalloyed good, orat least that any effects on performance are small (for simple programsthat don't cascade to a huge set of shared libraries). This isn'tnecessarily so.

A long time ago, back when dynamic linking was new and people weresuspicious of it, I conducted some timings of how dynamic linkingaffected the speed of fork() . To my surprise, the impact wassignificant, and on the hardware of the day it was

Originally, shared libraries and dynamic linking was sold as the way tomake (newly) bloated libraries tolerable: you'd only have one copy ofthe library on disk and in memory, no matter how many Motif applicationsyou had running. (Motif in specific and GUI libraries were really theoriginal poster boys for shared libraries.)

As R. Francis Smith notes in his comment on my previous entry , these reasons are not entirely relevant any more.Disk space is cheap, and (although I haven't