symon/symon/symon/symon.8

.\"  -*- nroff -*-
.\"
.\" Copyright (c) 2001-2005 Willem Dijkstra
.\" All rights reserved.
.\"
.\" Redistribution and use in source and binary forms, with or without
.\" modification, are permitted provided that the following conditions
.\" are met:
.\"
.\"    - Redistributions of source code must retain the above copyright
.\"      notice, this list of conditions and the following disclaimer.
.\"    - Redistributions in binary form must reproduce the above
.\"      copyright notice, this list of conditions and the following
.\"      disclaimer in the documentation and/or other materials provided
.\"      with the distribution.
.\"
.\" THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
.\" "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
.\" LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
.\" FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
.\" COPYRIGHT HOLDERS OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
.\" INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
.\" BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
.\" LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
.\" CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
.\" ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
.\" POSSIBILITY OF SUCH DAMAGE.
.\"
.Dd August 8, 2004
.Dt SYMON 8
.Os
.Sh NAME
.Nm symon
.Nd system monitor
.Sh SYNOPSIS
.Nm
.Op Fl duv
.Op Fl f Ar filename
.Pp
.Sh DESCRIPTION
.Nm
is a lightweight system monitor that measures cpu, memory, debug,
process, interface and disk statistics every 5 seconds. This information
is then spooled to
.Xr symux 8
for further processing.
.Pp
.Nm
has been designed to inflict minimal performance and security impact on
the system it monitors.
.Xr symux 8
has performance impact proportional to the amount of streams it needs to
manage. Ideally
.Xr symux
should live on a different system and collect data from several
.Nm
instances in a LAN.
.Lp
By default,
.Nm
will drop privileges and chroot(2) to home of the symon user.  This behaviour
is not strictly needed for the cpu, mem, mbuf, disk debug and interface probes
as these will work even when
.Nm
is started as
.Ar "nobody".
.Lp
The options:
.Bl -tag -width Ds
.It Fl d
Stop
.Nm
from becoming a daemon and show debug information on stdout.
.It Fl f Ar filename
Read configuration from
.Ar filename
instead of
.Pa /etc/symon.conf .
.It Fl u
By default
.Nm
will chroot(2) into
.Pa _symon
user home directory. The
.Pa -u
disables this behaviour.
.It Fl v
Show version information.
.El
.Sh CONFIGURATION
.Nm
obtains configuration data from
.Pa /etc/symon.conf .
The configuration file contains monitor stanzas that define what
resources should be monitored and to which
.Xr symux 8
the information should be streamed to.
.Pp
Multiple monitor statements to different muxes are allowed. Whitespace,
newlines and text behind '#' are ignored. The format in BNF:
.Pp
.nf
monitor-rule = "monitor" "{" resources "}" [every]
               "stream" ["to"] host [ port ]
resources    = resource ["(" argument ")"] [ ","|" " resources ]
argument     = number | interfacename | diskname
resource     = "cpu" | "mem" | "if" | "io" | "pf" | "pfq" |
               "debug" | "proc" | "mbuf" | "sensor" | "df"
every        = "every" time
time         = "second" | number "seconds"
host         = ip4addr | ip6addr | hostname
port         = [ "port" | "," ] portnumber
.fi
.Pp
Note that symux(8) data files default to receiving data every 5
seconds. Adjusting the monitoring interval will also require adjusting every
symux(8) datafile.
.Pp
The pf probe will return data that is collected for the
.Pa loginterface
set in /etc/pf.conf(5).
.Sh EXAMPLE
Here is an example
.Ar symon.conf
that monitors cpu, memory, pf, interfaces xl0/de0/lo0/wi0, disks
wd[0-3]/cd[0-1], debug variables debug0 to debug19 and streams that
information to localhost on port 2100.
.Pp
.nf
monitor { cpu(0),  mem, pf, if(xl0), if(de0),
	  if(lo0), if(wi0), io(wd0), io(wd1),
	  io(wd2), io(wd3), io(cd0), io(cd1),
	  io(ccd0), df(sd0a), df(sd0d), df(sd0e),
	  debug, proc(httpd) } stream to 127.0.0.1 2100
.fi
.Sh SIGNALS
.Bl -tag -width Ds
.It SIGHUP
Causes
.Nm
to read
.Pa /etc/symon.conf .
.Nm
will keep the old configuration if errors occured during parsing of the
configuration file. Note that the chroot(2) may cause resources to become
unattainable, most notably the configuration file itself.
.El
.Sh FILES
.Bl -tag -width Ds
.It Pa /var/run/symon.pid
Contains the program id of the
.Nm
daemon.
.It Pa /etc/symon.conf
.Nm
system wide configuration file.
.El
.Sh BUGS
Every monitored resource mentioned
.Pa /etc/symon.conf
gets queried. Mentioning, for example, cpu(0) twice for different muxes will
result in two distinct cpu(0) measurement actions.
.Pp
The proc module is too simple: memory shared between two instances of the same
process is simply counted twice.
.Pp
.Nm
does not check whether resources mentioned in
.Pa /etc/symon.conf
exist.
.Pp
.Sh AUTHOR
Willem Dijkstra <wpd@xs4all.nl>. Daniel Hartmeier helped to port to big-endian
architectures. Matthew Gream helped to port symon to other BSD platforms.

Port contributors: Marc Balmer, Matthew Gream, Daniel Hartmeier, J. Martin
Petersen, Fredrik Soderblom and Harm Schotanus.
.Sh SEE ALSO
.Xr symux 8