i have 4 nginx and the same configuration use lvs dr load balance, two of them have this problem:
Active connections: 4476
server accepts handled requests
27097803 27097803 27064329
Reading: 1959 Writing: 2517 Waiting: 0
# netstat -an | wc -l
459

and the normal server:
Active connections: 8
server accepts handled requests
58386943 58386943 58312509
Reading: 2 Writing: 6 Waiting: 0
# netstat -an | wc -l
1104

These two error server have the same kernel version:
Linux abc.com 2.6.9-78.ELsmp #1 SMP Wed Jul 9 15:46:26 EDT 2008 x86_64 x86_64 x86_64 GNU/Linux

I do not know where it went wrong.