MINOR: doc: document the -x flag

doc/haproxy.1

@@ -6,7 +6,7 @@ HAProxy \- fast and reliable http reverse proxy and load balancer
 
 .SH SYNOPSIS
 
-haproxy \-f <configuration\ file|dir> [\-L\ <name>] [\-n\ maxconn] [\-N\ maxconn] [\-C\ <dir>] [\-v|\-vv] [\-d] [\-D] [\-q] [\-V] [\-c] [\-p\ <pidfile>] [\-dk] [\-ds] [\-de] [\-dp] [\-db] [\-dM[<byte>]] [\-m\ <megs>] [{\-sf|\-st}\ pidlist...]
+haproxy \-f <configuration\ file|dir> [\-L\ <name>] [\-n\ maxconn] [\-N\ maxconn] [\-C\ <dir>] [\-v|\-vv] [\-d] [\-D] [\-q] [\-V] [\-c] [\-p\ <pidfile>] [\-dk] [\-ds] [\-de] [\-dp] [\-db] [\-dM[<byte>]] [\-m\ <megs>] [\-x <unix_socket>] [{\-sf|\-st}\ pidlist...]
 
 .SH DESCRIPTION
 
@@ -155,6 +155,12 @@ which receive this signal will terminate immediately, closing all active
 sessions. This option must be specified last, followed by any number of
 PIDs. Technically speaking, \fBSIGTTOU\fP and \fBSIGTERM\fP are sent.
 
+.TP
+\f8\-x <unix_socket>\fP
+Attempt to connect to the unix socket, and retrieve all the listening sockets
+from the old process. Those sockets will then be used if possible instead of
+binding new ones.
+
 .SH 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,

doc/management.txt

@@ -277,6 +277,11 @@ list of options is :
   -vv : display the version, build options, libraries versions and usable
     pollers. This output is systematically requested when filing a bug report.
 
+  -x <unix_socket> : connect to the specified socket and try to retrieve any
+    listening sockets from the old process, and use them instead of trying to
+    bind new ones. This is useful to avoid missing any new connection when
+    reloading the configuration on Linux.
+
 A safe way to start HAProxy from an init file consists in forcing the daemon
 mode, storing existing pids to a pid file and using this pid file to notify
 older processes to finish before leaving :