Administration guide > Tune and 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 and performance
Related concepts
Plan for network ports
ORB properties and file descriptor settings
JVM tuning for WebSphere eXtreme Scale
Use WebSphere Real Time
Related tasks
Configure failover detection
Tune the dynamic cache provider
Tune the cache sizing agent for accurate memory consumption estimates
Related reference