http://gwan.com/en_apachebench_httperf.html

sysctl.conf

# "Performance Scalability of a Multi-Core Web Server", Nov 2007
# Bryan Veal and Annie Foong, Intel Corporation, Page 4/10
fs.file-max = 5000000                      
net.core.netdev_max_backlog = 4096        
net.core.optmem_max = 10000000            
net.core.rmem_default = 10000000          
net.core.rmem_max = 10000000             
net.core.somaxconn = 4096                
net.core.wmem_default = 10000000          
net.core.wmem_max = 10000000              
net.ipv4.conf.all.rp_filter = 1           
net.ipv4.conf.default.rp_filter = 1       
net.ipv4.ip_local_port_range = 1024 65535 
net.ipv4.tcp_congestion_control = bic     
net.ipv4.tcp_ecn = 0                      
net.ipv4.tcp_max_syn_backlog = 12000
net.ipv4.tcp_max_tw_buckets = 2000000
net.ipv4.tcp_mem = 30000000 30000000 30000000
net.ipv4.tcp_rmem = 30000000 30000000 30000000
net.ipv4.tcp_sack = 1
net.ipv4.tcp_syncookies = 0
net.ipv4.tcp_timestamps = 1
net.ipv4.tcp_wmem = 30000000 30000000 30000000    

# optionally, avoid TIME_WAIT states on localhost no-HTTP Keep-Alive tests:
#    "error: connect() failed: Cannot assign requested address (99)"
# On Linux, the 2MSL time is hardcoded to 60 seconds in /include/net/tcp.h:
# #define TCP_TIMEWAIT_LEN (60*HZ)
# The option below is safe to use:
net.ipv4.tcp_tw_reuse = 1

# The option below lets you reduce TIME_WAITs further
# but this option is for benchmarks, NOT for production (NAT issues)
net.ipv4.tcp_tw_recycle = 1

# from: http://gwan.com/en_apachebench_httperf.html