Nodebalancer put's nodes offline due passive check
The nodebalancer is putting my servers offline in a random way. When contacting linode support they came to the conclusion that there are no 500 errors, but connections are dropped (or timeout).
I can't find anything in my nginx logs. Is there any way to debug this problem and see what connections have been timed-out dropped by nginx?
I can see a lot of 408 requests from the same IP/user agent. They come in by bulk.. Is this suspicious? How would you handle this situation? Snapshot from access.log
69.30.*.* - - [22/Apr/2014:19:28:29 +0200] "POST /error/register-image-error/ HTTP/1.1" 408 0 "http://www.mysite.com/" "Mozilla/4.0 (compatible; MSIE 6.0; Windows NT 5.1; SV1)"
69.30.*.* - - [22/Apr/2014:19:28:29 +0200] "POST /error/register-image-error/ HTTP/1.1" 408 0 "http://www.mysite.com/" "Mozilla/4.0 (compatible; MSIE 6.0; Windows NT 5.1; SV1)"
69.30.*.* - - [22/Apr/2014:19:28:29 +0200] "POST /error/register-image-error/ HTTP/1.1" 408 0 "http://www.mysite.com/" "Mozilla/4.0 (compatible; MSIE 6.0; Windows NT 5.1; SV1)"
69.30.*.* - - [22/Apr/2014:19:28:29 +0200] "POST /error/register-image-error/ HTTP/1.1" 408 0 "http://www.mysite.com/" "Mozilla/4.0 (compatible; MSIE 6.0; Windows NT 5.1; SV1)"
69.30.*.* - - [22/Apr/2014:19:28:29 +0200] "POST /error/register-image-error/ HTTP/1.1" 408 0 "http://www.mysite.com/" "Mozilla/4.0 (compatible; MSIE 6.0; Windows NT 5.1; SV1)"
69.30.*.* - - [22/Apr/2014:19:28:29 +0200] "POST /error/register-image-error/ HTTP/1.1" 408 0 "http://www.mysite.com/" "Mozilla/4.0 (compatible; MSIE 6.0; Windows NT 5.1; SV1)"
69.30.*.* - - [22/Apr/2014:19:28:29 +0200] "POST /error/register-image-error/ HTTP/1.1" 408 0 "http://www.mysite.com/" "Mozilla/4.0 (compatible; MSIE 6.0; Windows NT 5.1; SV1)"
69.30.*.* - - [22/Apr/2014:19:28:29 +0200] "POST /error/register-image-error/ HTTP/1.1" 408 0 "http://www.mysite.com/" "Mozilla/4.0 (compatible; MSIE 6.0; Windows NT 5.1; SV1)"
69.30.*.* - - [22/Apr/2014:19:28:29 +0200] "POST /error/register-image-error/ HTTP/1.1" 408 0 "http://www.mysite.com/" "Mozilla/4.0 (compatible; MSIE 6.0; Windows NT 5.1; SV1)"
69.30.*.* - - [22/Apr/2014:19:28:29 +0200] "POST /error/register-image-error/ HTTP/1.1" 408 0 "http://www.mysite.com/" "Mozilla/4.0 (compatible; MSIE 6.0; Windows NT 5.1; SV1)"
69.30.*.* - - [22/Apr/2014:19:28:29 +0200] "POST /error/register-image-error/ HTTP/1.1" 408 0 "http://www.mysite.com/" "Mozilla/4.0 (compatible; MSIE 6.0; Windows NT 5.1; SV1)"
69.30.*.* - - [22/Apr/2014:19:28:29 +0200] "POST /error/register-image-error/ HTTP/1.1" 408 0 "http://www.mysite.com/" "Mozilla/4.0 (compatible; MSIE 6.0; Windows NT 5.1; SV1)"
69.30.*.* - - [22/Apr/2014:19:28:29 +0200] "POST /error/register-image-error/ HTTP/1.1" 408 0 "http://www.mysite.com/" "Mozilla/4.0 (compatible; MSIE 6.0; Windows NT 5.1; SV1)"
69.30.*.* - - [22/Apr/2014:19:28:29 +0200] "POST /error/register-image-error/ HTTP/1.1" 408 0 "http://www.mysite.com/" "Mozilla/4.0 (compatible; MSIE 6.0; Windows NT 5.1; SV1)"
69.30.*.* - - [22/Apr/2014:19:28:29 +0200] "POST /error/register-image-error/ HTTP/1.1" 408 0 "http://www.mysite.com/" "Mozilla/4.0 (compatible; MSIE 6.0; Windows NT 5.1; SV1)"
69.30.*.* - - [22/Apr/2014:19:28:29 +0200] "POST /error/register-image-error/ HTTP/1.1" 408 0 "http://www.mysite.com/" "Mozilla/4.0 (compatible; MSIE 6.0; Windows NT 5.1; SV1)"
69.30.*.* - - [22/Apr/2014:19:28:29 +0200] "POST /error/register-image-error/ HTTP/1.1" 408 0 "http://www.mysite.com/" "Mozilla/4.0 (compatible; MSIE 6.0; Windows NT 5.1; SV1)"
69.30.*.* - - [22/Apr/2014:19:28:30 +0200] "POST /error/register-image-error/ HTTP/1.1" 408 0 "http://www.mysite.com/" "Mozilla/4.0 (compatible; MSIE 6.0; Windows NT 5.1; SV1)"
69.30.*.* - - [22/Apr/2014:19:28:30 +0200] "POST /error/register-image-error/ HTTP/1.1" 408 0 "http://www.mysite.com/" "Mozilla/4.0 (compatible; MSIE 6.0; Windows NT 5.1; SV1)"
69.30.*.* - - [22/Apr/2014:19:28:30 +0200] "POST /error/register-image-error/ HTTP/1.1" 408 0 "http://www.mysite.com/" "Mozilla/4.0 (compatible; MSIE 6.0; Windows NT 5.1; SV1)"
69.30.*.* - - [22/Apr/2014:19:28:30 +0200] "POST /error/register-image-error/ HTTP/1.1" 408 0 "http://www.mysite.com/" "Mozilla/4.0 (compatible; MSIE 6.0; Windows NT 5.1; SV1)"
69.30.*.* - - [22/Apr/2014:19:28:30 +0200] "POST /error/register-image-error/ HTTP/1.1" 408 0 "http://www.mysite.com/" "Mozilla/4.0 (compatible; MSIE 6.0; Windows NT 5.1; SV1)"
69.30.*.* - - [22/Apr/2014:19:28:30 +0200] "POST /error/register-image-error/ HTTP/1.1" 408 0 "http://www.mysite.com/" "Mozilla/4.0 (compatible; MSIE 6.0; Windows NT 5.1; SV1)"
69.30.*.* - - [22/Apr/2014:19:28:30 +0200] "POST /error/register-image-error/ HTTP/1.1" 408 0 "http://www.mysite.com/" "Mozilla/4.0 (compatible; MSIE 6.0; Windows NT 5.1; SV1)"
69.30.*.* - - [22/Apr/2014:19:28:30 +0200] "POST /error/register-image-error/ HTTP/1.1" 408 0 "http://www.mysite.com/" "Mozilla/4.0 (compatible; MSIE 6.0; Windows NT 5.1; SV1)"
69.30.*.* - - [22/Apr/2014:19:28:30 +0200] "POST /error/register-image-error/ HTTP/1.1" 408 0 "http://www.mysite.com/" "Mozilla/4.0 (compatible; MSIE 6.0; Windows NT 5.1; SV1)"
69.30.*.* - - [22/Apr/2014:19:28:30 +0200] "POST /error/register-image-error/ HTTP/1.1" 408 0 "http://www.mysite.com/" "Mozilla/4.0 (compatible; MSIE 6.0; Windows NT 5.1; SV1)"
69.30.*.* - - [22/Apr/2014:19:28:30 +0200] "POST /error/register-image-error/ HTTP/1.1" 408 0 "http://www.mysite.com/" "Mozilla/4.0 (compatible; MSIE 6.0; Windows NT 5.1; SV1)"
69.30.*.* - - [22/Apr/2014:19:28:30 +0200] "POST /error/register-image-error/ HTTP/1.1" 408 0 "http://www.mysite.com/" "Mozilla/4.0 (compatible; MSIE 6.0; Windows NT 5.1; SV1)"
69.30.*.* - - [22/Apr/2014:19:28:30 +0200] "POST /error/register-image-error/ HTTP/1.1" 408 0 "http://www.mysite.com/" "Mozilla/4.0 (compatible; MSIE 6.0; Windows NT 5.1; SV1)"
69.30.*.* - - [22/Apr/2014:19:28:30 +0200] "POST /error/register-image-error/ HTTP/1.1" 408 0 "http://www.mysite.com/" "Mozilla/4.0 (compatible; MSIE 6.0; Windows NT 5.1; SV1)"
69.30.*.* - - [22/Apr/2014:19:28:30 +0200] "POST /error/register-image-error/ HTTP/1.1" 408 0 "http://www.mysite.com/" "Mozilla/4.0 (compatible; MSIE 6.0; Windows NT 5.1; SV1)"
69.30.*.* - - [22/Apr/2014:19:28:30 +0200] "POST /error/register-image-error/ HTTP/1.1" 408 0 "http://www.mysite.com/" "Mozilla/4.0 (compatible; MSIE 6.0; Windows NT 5.1; SV1)"
69.30.*.* - - [22/Apr/2014:19:28:30 +0200] "POST /error/register-image-error/ HTTP/1.1" 408 0 "http://www.mysite.com/" "Mozilla/4.0 (compatible; MSIE 6.0; Windows NT 5.1; SV1)"
69.30.*.* - - [22/Apr/2014:19:28:30 +0200] "POST /error/register-image-error/ HTTP/1.1" 408 0 "http://www.mysite.com/" "Mozilla/4.0 (compatible; MSIE 6.0; Windows NT 5.1; SV1)"
69.30.*.* - - [22/Apr/2014:19:28:30 +0200] "POST /error/register-image-error/ HTTP/1.1" 408 0 "http://www.mysite.com/" "Mozilla/4.0 (compatible; MSIE 6.0; Windows NT 5.1; SV1)"
69.30.*.* - - [22/Apr/2014:19:28:30 +0200] "POST /error/register-image-error/ HTTP/1.1" 408 0 "http://www.mysite.com/" "Mozilla/4.0 (compatible; MSIE 6.0; Windows NT 5.1; SV1)"
69.30.*.* - - [22/Apr/2014:19:28:30 +0200] "POST /error/register-image-error/ HTTP/1.1" 408 0 "http://www.mysite.com/" "Mozilla/4.0 (compatible; MSIE 6.0; Windows NT 5.1; SV1)"
69.30.*.* - - [22/Apr/2014:19:28:31 +0200] "POST /error/register-image-error/ HTTP/1.1" 408 0 "http://www.mysite.com/" "Mozilla/4.0 (compatible; MSIE 6.0; Windows NT 5.1; SV1)"
69.30.*.* - - [22/Apr/2014:19:28:31 +0200] "POST /error/register-image-error/ HTTP/1.1" 408 0 "http://www.mysite.com/" "Mozilla/4.0 (compatible; MSIE 6.0; Windows NT 5.1; SV1)"
69.30.*.* - - [22/Apr/2014:19:28:31 +0200] "POST /error/register-image-error/ HTTP/1.1" 408 0 "http://www.mysite.com/" "Mozilla/4.0 (compatible; MSIE 6.0; Windows NT 5.1; SV1)"
69.30.*.* - - [22/Apr/2014:19:28:31 +0200] "POST /error/register-image-error/ HTTP/1.1" 408 0 "http://www.mysite.com/" "Mozilla/4.0 (compatible; MSIE 6.0; Windows NT 5.1; SV1)"
Thanks!