tcpkali -em "GET / HTTP/1.1\r\nHost: google.com\r\n\r\n" -r 10 --latency-marker "HTTP/1.1" google.com:80

test -f configure || autoreconf -iv
./configure
make
sudo make install

Usage: tcpkali [OPTIONS] <host:port> [<host:port>...]
Where OPTIONS are:
  -h, --help                   Print this help screen, then exit
  --version                    Print version number, then exit
  -v, --verbose <level=1>      Increase (-v) or set verbosity level [0..3]
  -w, --workers <N>            Number of parallel threads to use
  --nagle {on|off}             Control Nagle algorithm (set TCP_NODELAY)
  --rcvbuf <Sizebytes>         Set TCP receive buffers (set SO_RCVBUF)
  --sndbuf <Sizebytes>         Set TCP rend buffers (set SO_SNDBUF)
  --source-ip <IP>             Use the specified IP address to connect


  --ws, --websocket            Use RFC6455 WebSocket transport
  -c, --connections <N=1>      Connections to keep open to the destinations
  --connect-rate <Rate=100>    Limit number of new connections per second
  --connect-timeout <Time=1s>  Limit time spent in a connection attempt
  --channel-lifetime <Time>    Shut down each connection after Time seconds
  --channel-bandwidth-upstream <Bandwidth>     Limit upstream bandwidth
  --channel-bandwidth-downstream <Bandwidth>   Limit downstream bandwidth
  -l, --listen-port <port>     Listen on the specified port
  --listen-mode=<mode>         What to do upon client connect, where <mode> is:
               "silent"        Do not send data, ignore received data (default)
               "active"        Actively send messages
  -T, --duration <Time=10s>    Exit after the specified amount of time

  -e, --unescape-message-args  Unescape the message data arguments
  --first-message <string>     Send this message first, once
  --first-message-file <name>  Read the first message from a file
  -m, --message <string>       Message to repeatedly send to the remote
  -f, --message-file <name>    Read message to send from a file
  -r, --message-rate <Rate>    Messages per second to send in a connection

  --latency-marker <string>    Measure latency using a per-message marker
  --latency-marker-skip <N>    Ignore the first N occurrences of a marker

  --statsd                     Enable StatsD output (default disabled)
  --statsd-host <host>         StatsD host to send data (default is localhost)
  --statsd-port <port>         StatsD port to use (default is 8125)
  --statsd-namespace <string>  Metric namespace (default is "tcpkali")

Variable units and recognized multipliers:
  <N>, <Rate>:  k (1000, as in "5k" is 5000), m (1000000)
  <Sizebytes>:  k (1024, as in "5k" is 5120), m (1024*1024)
  <Bandwidth>:  kbps, Mbps (bits per second), kBps, MBps (bytes per second)
  <Time>:       ms, s, m, h, d (milliseconds, seconds, minutes, hours, days)
  <Rate> and <Time> can be fractional values, such as 0.25.

tcpkali 127.0.0.1:80

tcpkali --message '$' localhost:echo
tcpkali -m '$' localhost:echo

tcpkali --connections 10000 yahoo.com:80 google.com:80
tcpkali -c 10000 yahoo.com:80 google.com:80

tcpkali --connections 100 --listen-port 12345 127.0.0.1:12345
tcpkali -c100 -l12345 127.0.0.1:12345

tcpkali --listen-port 12345 --message "cookies" 127.0.0.1:12345
tcpkali -l 12345 -m "cookies" 127.0.0.1:12345

tcpkali --listen-port 12345 --duration 3h
tcpkali -l12345 -T3h

tcpkali --websocket --first-message "hello" 127.0.0.1:80

tcpkali --websocket --message "{}" 127.0.0.1:80

tcpkali --websocket --message "{}" --message-rate=1 127.0.0.1:80

kern.maxfiles=10000+2*N         # BSD
kern.maxfilesperproc=100+N      # BSD
fs.file-max=10000+2*N           # Linux

# For load-generating clients.
net.ipv4.ip_local_port_range="10000  65535"  # Linux.
net.inet.ip.portrange.hifirst=10000          # BSD/Mac.
net.inet.ip.portrange.hilast=65535           # (Enough for N < 55535)
net.ipv4.tcp_tw_reuse=1

# If using netfilter on Linux:
net.netfilter.nf_conntrack_max=N