Strange 400 errors in lighttpd?

Question

linux

From time to time I get 400 errors in lighttpd logs, the system hosts a mobile application, when I test urls manually, I always get normal answers. The system works according to the scheme lighttpd + php-factcgi

10.85.67.19 - [22/Aug/2012:09:31:20 +0000] "GET /?app_version=1.4.7&device_type=9800&device_os=6.0.0.576&mcc=1296&mnc=16&network_name=IND % 20TEL
KOMSEL & task = logFriendsUserAction & from_pin = 276DC1FD & ACTION_TYPE = 13 & session_duration = 43 & hash = d1301e92c34d0d7f28815dfbe484d607 HTTP / 1.1 »400 226" - "" - "
10.85.67.19 - [22 / Aug / 2012: 09: 31: 20 +0000]« GET / app_version =? 1.4.7&device_type=9700&device_os=5.0.0.1014&mcc=1296&mnc=16&network_name=IND%20TE
LKOMSEL&task=logFriendsUserAction&from_pin=229FCF27&action_type=13&
10.85.67.19 - [22/Aug/2012:09:31:20 +0000] "GET /?task=checkAppVersion&from_pin=28A3C3E0&app_version=1.4.5&device_type=9810&device_os=7.0.0.296
&mcc=1569&mnc=80&network_name=Gloapp%_Mobile 20Avatarslanguage_id=93&hash=c283cb69609e6857a0e0bda832547e89 HTTP/1.1» 400 216 "-" "-"

I don't know why they climb.

Answer 1

HTTP 400 - BAd request
usually occurs with bad headers or if the headers do not fit in the buffer (due to the large number of parameters or the large volume of values ​​\u200b\u200bof these parameters)