Hi, I'm new to nginx. I am using nginx as a reverse proxy to access the tomcat. visiting by 1100 concurrent threads, the nginx can't run correctly. there are a lot of "110: Connection timed out" and "104: Connection reset by peer" errors in my error.log，more details is as follows：
2013/05/22 13:00:54 [error] 5238#0: *236951627 connect() failed (110: Connection timed out) while connecting to upstream, client: 192.168.0.72, server: testopenfire.fdautotest.com, request: "GET /login.jsp HTTP/1.1", upstream: "http://192.168.1.46:9090/login.jsp", host: "testopenfire.fdautotest.com"
2013/05/22 13:05:45 [error] 5236#0: *237448096 recv() failed (104: Connection reset by peer) while reading response header from upstream, client: 192.168.0.72, server: test201.fdautotest.com, request: "GET /botAssist/ HTTP/1.1", upstream: "http://192.168.4.201:8081/botAssist/", host: "test201.fdautotest.com"

nginx.conf:
#user nobody;
worker_processes 8;
worker_cpu_affinity 00000001 00000010 00000100 00001000 00010000 00100000 01000000 10000000;
#error_log logs/error.log;
#error_log logs/error.log notice;
#error_log logs/error.log info;
#pid logs/nginx.pid;
worker_rlimit_nofile 65535;
events {
use epoll;
worker_connections 65535;
}
http {
include mime.types;
default_type application/octet-stream;
server_names_hash_bucket_size 128;
client_header_buffer_size 4k;
large_client_header_buffers 4 16k;
client_max_body_size 300m;
open_file_cache max=65535 inactive=60s;
open_file_cache_min_uses 1;
open_file_cache_valid 30s;
tcp_nodelay on;
tcp_nopush on;
proxy_connect_timeout 500;
proxy_read_timeout 500;
proxy_send_timeout 500;
proxy_buffer_size 64k;
proxy_buffers 4 32k;
proxy_busy_buffers_size 64k;
proxy_temp_file_write_size 64k;
proxy_set_header Host $host;
proxy_set_header X-Real-IP $remote_addr;
proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;
proxy_set_header X-Forwarded-Proto $scheme;
#log_format main '$remote_addr - $remote_user [$time_local] "$request" '
# '$status $body_bytes_sent "$http_referer" '
# '"$http_user_agent" "$http_x_forwarded_for"';
#access_log logs/access.log main;
sendfile on;
keepalive_timeout 120;
include serverconfs/*;
server {
listen 80;
server_name localhost;
location / {
#root html;
#index ip.html index.html index.htm;
proxy_pass http://192.168.7.118:8083/;
}
error_page 500 502 503 504 /50x.html;
location = /50x.html {
root html;
}
}
}

serverconfs/test201.fdautotest.com(other included files are similar to test201.fdautotest.com):
server {
listen 80;
server_name test201.fdautotest.com;
location /botAssist/ {
proxy_pass http://192.168.4.201:8081/botAssist/;
}
location / {
proxy_pass http://192.168.4.201:8081/;
}
location /admin {
return 404;
}
location /manager/html {
return 404;
}
}

/etc/sysctl.conf:
# Kernel sysctl configuration file for Red Hat Linux
#
# For binary values, 0 is disabled, 1 is enabled. See sysctl(8) and
# sysctl.conf(5) for more details.
net.ipv4.conf.eth0.arp_ignore=1
net.ipv4.conf.eth0.arp_announce=1
kernel.sysrq = 0
kernel.core_uses_pid = 1
kernel.msgmnb = 65536
kernel.msgmax = 65536
kernel.shmmax = 68719476736
kernel.shmall = 4294967296
net.core.wmem_default = 8388608
net.core.rmem_default = 8388608
net.core.rmem_max = 16777216
net.core.wmem_max = 16777216
net.core.netdev_max_backlog = 262144
net.core.somaxconn = 262144
net.ipv4.ip_forward = 0
net.ipv4.conf.default.rp_filter = 1
net.ipv4.conf.default.accept_source_route = 0
net.ipv4.tcp_max_tw_buckets = 60000
net.ipv4.tcp_sack = 1
net.ipv4.tcp_window_scaling = 1
net.ipv4.tcp_rmem = 4096 87380 4194304
net.ipv4.tcp_wmem = 4096 16384 4194304
net.ipv4.tcp_max_orphans = 3276800
net.ipv4.tcp_max_syn_backlog = 262144
net.ipv4.tcp_timestamps = 0
net.ipv4.tcp_synack_retries = 1
net.ipv4.tcp_syn_retries = 1
net.ipv4.tcp_tw_recycle = 1
net.ipv4.tcp_tw_reuse = 1
net.ipv4.tcp_syncookies = 1
net.ipv4.tcp_mem = 94500000 915000000 927000000
net.ipv4.tcp_fin_timeout = 30
net.ipv4.tcp_keepalive_time = 30
net.ipv4.ip_local_port_range = 1024 65000
net.nf_conntrack_max = 655360
net.netfilter.nf_conntrack_tcp_timeout_established = 1200

Do you have any solutions?