Software Logging Schemes?

MySkippy writes "I've been a software engineer for just over 10 years, and I've seen a lot of different styles of logging in the applications I've worked on. Some were extremely verbose — about 1 logging line for every 2 lines of code. Others were very lacking, with maybe 1 line in 200 devoted to logging. I personally find that writing debug and informational messages about every 2 to 5 lines works well for debugging an issue, but can become cumbersome when reading through a log for analysis. I like to write warning messages when thresholds or limits are being approached — these tend to be infrequent. I log errors whenever I catch one (but I've never put a 'fatal' message in my code, because if it's truly a fatal error I probably didn't catch it). Recently I came across log4j and log4net and have begun using them both. That brings me to my question: how do the coders on Slashdot handle logging in their code?"

Comments

Re:As little as practically possible

[darkpixel2k]

...nothing's as frustrating as trying to analyze a log that came in from the field where there's just no information about what went wrong.

[ 56.529336] WARNING: A-fib detected
[ 56.568802] INFO: charging defib
[ 56.741096] INFO: charging ccomplete
[ 57.218803] ALERT: shocking!
[ 58.061815] Buffer I/O error on /dev/paddles
[ 58.163210] zapper[22402]: segfault at 000000c4 eip b321bf5f esp b320a870 error 6
BUG: unable to handle kernel NULL pointer dereference at virtual adress 00000000
printing eip: c013186b *pde = 00000000
Oops: 0000 [#1] SMP
Modules linked in: battery ipv6 paddles ac button battery cardiac_monitor thermal processor zapper fan

Man, I'd feel bad after that output...