WebSphere eXtreme Scale Administration Guide > Plan application deployment > Tune performance



Operating systems and network tuning


Network tuning can reduce Transmission Control Protocol (TCP) stack delay by changing connection settings and can improve throughput by changing TCP buffers.


Operating systems

A Windows system needs the least tuning while a Solaris system needs the most tuning. The following information pertains to each system specified, and might improve WebSphere eXtreme Scale performance. You should tune according to the network and application load.


Windows

HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\
Tcpip\Parameters
MaxFreeTcbs = dword:00011940
MaxHashTableSize = dword:00010000
MaxUserPort = dword:0000fffe
TcpTimedWaitDelay = dword:0000001e


Solaris

ndd -set /dev/tcp tcp_time_wait_interval 60000
fndd -set /dev/tcp tcp_keepalive_interval 15000
ndd -set /dev/tcp tcp_fin_wait_2_flush_interval 67500
ndd -set /dev/tcp tcp_conn_req_max_q 16384
ndd -set /dev/tcp tcp_conn_req_max_q0 16384
ndd -set /dev/tcp tcp_xmit_hiwat 400000
ndd -set /dev/tcp tcp_recv_hiwat 400000
ndd -set /dev/tcp tcp_cwnd_max 2097152
ndd -set /dev/tcp tcp_ip_abort_interval 20000
ndd -set /dev/tcp tcp_rexmit_interval_initial 4000
ndd -set /dev/tcp tcp_rexmit_interval_max 10000
ndd -set /dev/tcp tcp_rexmit_interval_min 3000
ndd -set /dev/tcp tcp_max_buf 4194304


AIX

/usr/sbin/no -o tcp_sendspace=65536
/usr/sbin/no -o tcp_recvspace=65536
/usr/sbin/no -o udp_sendspace=65536
/usr/sbin/no -o udp_recvspace=65536
/usr/sbin/no -o somaxconn=10000
/usr/sbin/no -o tcp_nodelayack=1
/usr/sbin/no –o tcp_keepinit=40
/usr/sbin/no –o tcp_keepintvl=10


LINUX

sysctl -w net.ipv4.tcp_timestamps=0 
sysctl -w net.ipv4.tcp_tw_reuse=1 
sysctl -w net.ipv4.tcp_tw_recycle=1 
sysctl -w net.ipv4.tcp_fin_timeout=30 
sysctl -w net.ipv4.tcp_keepalive_time=1800 
sysctl -w net.ipv4.tcp_rmem="4096 87380 8388608" 
sysctl -w net.ipv4.tcp_wmem="4096 87380 8388608" 
sysctl -w net.ipv4.tcp_max_syn_backlog=4096 


HP-UX

ndd -set /dev/tcp tcp_ip_abort_cinterval 20000 



Parent topic

Tune performance


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