Network tuning can reduce Transmission Control Protocol (TCP) stack delay by changing connection settings and can improve throughput by changing TCP buffers.
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 your network and application load.
HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\ Tcpip\Parameters MaxFreeTcbs = dword:00011940 MaxHashTableSize = dword:00010000 MaxUserPort = dword:0000fffe TcpTimedWaitDelay = dword:0000001e
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
/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
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
ndd -set /dev/tcp tcp_ip_abort_cinterval 20000