Lighttpd

If server.max-worker >1 (e.g. 2 or 3) and pipe logging is used, for example:

server.max-worker = 4
accesslog.filename = "| /home/work/cronolog -S /home/work/lighttpd/log/access_log /home/work/lighttpd/log/access_log.%Y%m%d%H"

and use Apache ab:
./ab -c 100 -n 1000000 http://127.0.0.1:8080/index.html

you can see the accesslog is disorder:

...
127.0.0.1 - - [30/Dec/2009:17:58:39 +0800] "GET / HTTP/1.0" 200 5120 "http://test.example.com/1234567890abcdefghijklmnopqrstuvwxyz"
"ApacheBench/2.3"
127.0.0.1 - - [30/Dec/2009:17:58:39 +0800] "GET / HTTP/1.0" 200 5120 "http://test.example.com/1234567890abcdefghijklmnopqrstuvwxyz"
"ApacheBench/2.3"
127.0.0.1 - - [30/Dec/2009:17:58:39 +0800] "GET / HTTP/1.0" 200 5120 "http://test.example.com/1234567890abcdefghijklmnopqrstuvwxyz"
"ApacheBench/2.3"
T / HTTP/1.0" 200 5120 "http://test.example.com/1234567890abcdefghijklmnopqrstuvwxyz" "ApacheBench/2.3"
127.0.0.1 - - [30/Dec/2009:17:58:39 +0800] "GET / HTTP/1.0" 200 5120 "http://test.example.com/1234567890abcdefghijklmnopqrstuvwxyz"
"ApacheBench/2.3"
127.0.0.1 - - [30/Dec/2009:17:58:39 +0800] "GET / HTTP/1.0" 200 5120 "http://test.example.com/1234567890abcdefghijklmnopqrstuvwxyz"
"ApacheBench/2.3"
...
127.0.0.1 - - [30/Dec/2009:17:58:39 +0800] "GET / HTTP/1.0" 200 5120 "http://test.example.com/1234567890abcdefghijklmnopqrstuvwxyz"
"ApacheBench/2.3"
127.0.0.1 - - [30/Dec/2009:17:58:39 +0800] "GEeBench/2.3"
127.0.0.1 - - [30/Dec/2009:17:58:39 +0800] "GET / HTTP/1.0" 200 5120 "http://test.example.com/1234567890abcdefghijklmnopqrstuvwxyz"
"ApacheBench/2.3"
127.0.0.1 - - [30/Dec/2009:17:58:39 +0800] "GET / HTTP/1.0" 200 5120 "http://test.example.com/1234567890abcdefghijklmnopqrstuvwxyz"
"ApacheBench/2.3"
T / HTTP/1.0" 200 5120 "http://test.example.com/1234567890abcdefghijklmnopqrstuvwxyz" "ApacheBench/2.3"
127.0.0.1 - - [30/Dec/2009:17:58:39 +0800] "GET / HTTP/1.0" 200 5120 "http://test.example.com/1234567890abcdefghijklmnopqrstuvwxyz"
"ApacheBench/2.3"
127.0.0.1 - - [30/Dec/2009:17:58:39 +0800] "GET / HTTP/1.0" 200 5120 "http://test.example.com/1234567890abcdefghijklmnopqrstuvwxyz"
"ApacheBench/2.3"
127.0.0.1 - - [30/Dec/2009:17:58:39 +0800] "GET / HTTP/1.0" 200 5120 "http://test.example.com/1234567890abcdefghijklmnopqrstuvwxyz"
"ApacheBench/2.3"
...

It's because mod_accesslog.c has a bug in line 870:
870 (p->conf.access_logfile->used && p->conf.access_logfile->ptr⁰ != '|') || /* pipes don't cache */

=>

(p->conf.access_logfile->used && p->conf.access_logfile->ptr⁰ == '|') || /* pipes don't cache */

It's ok now.