Ubuntu Manpage: HAProxy - fast and reliable http reverse proxy and load balancer

Provided by: haproxy_1.4.24-2ubuntu0.4_amd64

NAME

       HAProxy - fast and reliable http reverse proxy and load balancer

SYNOPSIS

       haproxy  -f  <configuration file>  [-n maxconn]  [-N maxconn]  [-d]  [-D]  [-q]  [-V] [-c]
       [-p <pidfile>] [-s] [-l] [-dk] [-ds] [-de] [-dp] [-db] [-m <megs>] [{-sf|-st} pidlist...]

DESCRIPTION

       HAProxy is a TCP/HTTP reverse proxy which is particularly  suited  for  high  availability
       environments. Indeed, it can:
        - route HTTP requests depending on statically assigned cookies ;
        - spread the load among several servers while assuring server
          persistence through the use of HTTP cookies ;
        - switch to backup servers in the event a main one fails ;
        - accept connections to special ports dedicated to service
          monitoring ;
        - stop accepting connections without breaking existing ones ;
        - add/modify/delete HTTP headers both ways ;
        - block requests matching a particular pattern ;
        - hold clients to the right application server depending on
          application cookies
        - report detailed status as HTML pages to authenticated users from an
          URI intercepted from the application.

       It  needs  very  little resource. Its event-driven architecture allows it to easily handle
       thousands of simultaneous  connections  on  hundreds  of  instances  without  risking  the
       system's stability.

OPTIONS

-f <configuration file>
Specify configuration file path.

-n <maxconn>
Set the high limit for the total number of simultaneous connections.

-N <maxconn>
Set the high limit for the per-listener number of simultaneous connections.

-d Start in foregreound with debugging mode enabled. When the proxy runs in this
mode, it dumps every connections, disconnections, timestamps, and HTTP headers to
stdout. This should NEVER be used in an init script since it will prevent the
system from starting up.

-D Start in daemon mode.

-q Disable messages on output.

-V Displays messages on output even when -q or 'quiet' are specified. Some information
about pollers and config file are displayed during startup.

-c Only checks config file and exits with code 0 if no error was found, or exits with
code 1 if a syntax error was found.

-p <pidfile>
Ask the process to write down each of its children's pids to this file in daemon
mode.

-s Show statistics (only if compiled in). Statistics are only available if compiled
in with the 'STATTIME' option. It's only used during code optimization phases, and
will soon disappear.

-l Show even more statistics (implies '-s').

-dk Disable use of kqueue(). kqueue() is available only on BSD systems.

-ds Disable use of speculative epoll(). epoll() is available only on Linux 2.6 and some
custom Linux 2.4 systems.

-de Disable use of epoll(). epoll() is available only on Linux 2.6 and some custom
Linux 2.4 systems.

-dp Disables use of poll(). select() might be used instead.

-db Disables background mode (stays in foreground, useful for debugging). For
debugging, the '-db' option is very useful as it temporarily disables daemon mode
and multi-process mode. The service can then be stopped by simply pressing Ctrl-C,
without having to edit the config nor run full debug.

-m <megs>
Enforce a memory usage limit to a maximum of <megs> megabytes.

-sf <pidlist>
Send FINISH signal to the pids in pidlist after startup. The processes which
receive this signal will wait for all sessions to finish before exiting. This
option must be specified last, followed by any number of PIDs. Technically
speaking, SIGTTOU and SIGUSR1 are sent.

-st <pidlist>
Send TERMINATE signal to the pids in pidlist after startup. The processes which
receive this signal will wait immediately terminate, closing all active sessions.
This option must be specified last, followed by any number of PIDs. Technically
speaking, SIGTTOU and SIGTERM are sent.

LOGGING

       Since HAProxy can run inside a chroot, it  cannot  reliably  access  /dev/log.   For  this
       reason,  it  uses the UDP protocol to send its logs to the server, even if it is the local
       server. People who experience trouble receiving  logs  should  ensure  that  their  syslog
       daemon  listens  to  the  UDP socket.  Several Linux distributions which ship with syslogd
       from the sysklogd package have UDP disabled by default. The -r option must  be  passed  to
       the daemon in order to enable UDP.

SIGNALS

       Some  signals  have  a  special  meaning  for the haproxy daemon. Generally, they are used
       between daemons and need not be used by the administrator.

       - SIGUSR1
              Tells the daemon to stop all proxies and exit once all sessions are closed.  It  is
              often referred to as the "soft-stop" signal.

       - SIGTTOU
              Tells the daemon to stop listening to all sockets. Used internally by -sf and -st.

       - SIGTTIN
              Tells  the  daemon  to  restart  listening  to  all  sockets  after a SIGTTOU. Used
              internally when there was a problem during hot reconfiguration.

       - SIGINT and SIGTERM
              Both signals can be used to quickly stop the daemon.

       - SIGHUP
              Dumps the status of all proxies and servers into the logs. Mostly used for trouble-
              shooting purposes.

       - SIGQUIT
              Dumps  information  about  memory  pools  into  the logs. Mostly used for debugging
              purposes.

       - SIGPIPE
              This signal is intercepted and ignored on systems without MSG_NOSIGNAL.

AUTHOR

       HAProxy was written by Willy Tarreau. This man page was written by Arnaud Cornet and Willy
       Tarreau.

                                          17 August 2007                               HAPROXY(1)