High CPU when upstream server down

[adamn]

Nginx goes to nearly 100% CPU when I take down my upstream servers
(gunicorn).  Has anybody heard of this as an issue?


$ nginx -v
nginx version: nginx/0.7.67
$ uname -a
Linux ip-10-242-226-66 2.6.35-27-virtual #48-Ubuntu SMP Tue Feb 22
23:09:12 UTC 2011 i686 GNU/Linux


Summary of top:

top - 20:10:17 up 1 day, 29 min,  4 users,  load average: 1.11, 0.83,
0.56
Tasks:  79 total,   2 running,  77 sleeping,   0 stopped,   0 zombie
Cpu(s):  6.4%us, 36.9%sy,  0.0%ni,  0.0%id,  0.0%wa,  0.0%hi,  0.0%si,
56.7%st
Mem:   1705708k total,   442308k used,  1263400k free,    91240k
buffers
Swap:   917500k total,        0k used,   917500k free,   249920k cached

  PID USER      PR  NI  VIRT  RES  SHR S %CPU %MEM    TIME+  COMMAND    
                                
30663 www-data  20   0  5492 1944  916 R 99.9  0.1   5:26.32 nginx      
                                 
    1 root      20   0  2848 1652 1216 S  0.0  0.1   0:00.47 init       
                                 
    2 root      20   0     0    0    0 S  0.0  0.0   0:00.00 kthreadd   
                                 
    3 root      20   0     0    0    0 S  0.0  0.0   0:03.74 ksoftirqd/0
                                 
    4 root      RT   0     0    0    0 S  0.0  0.0   0:00.00 migration/0
                                 
    5 root      RT   0     0    0    0 S  0.0  0.0   0:00.20 watchdog/0 
                                 
    6 root      20   0     0    0    0 S  0.0  0.0   0:01.91 events/0   
                                 
    7 root      20   0     0    0    0 S  0.0  0.0   0:00.00 cpuset

Posted at Nginx Forum: http://forum.nginx.org/read.php?2,181397,181397#msg-181397