symon/symon/symon/symon.8

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.Dd April 5, 2002
.Dt SYMON 8
.Os
.Sh NAME
.Nm symon
.Nd system monitor
.Sh SYNOPSIS
.Nm 
.Op Fl vd
.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
.Nm
priviledge needs depend on the probes used. The cpu, mem, mbuf, disk,
debug and interface probes will work even when symon runs as
.Ar "nobody" . 
For pf, read and write access to 
.Pa /dev/pf
is needed, so 
.Nm 
will have to run as
.Ar "root".
.Lp
The options:
.Bl -tag -width Ds
.It Fl v
Show version information.
.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 .
.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 "}" "stream" ["to"] host [ port ]
resources    = resource ["(" argument ")"] [ ","|" " resources ]
resource     = "cpu" | "mem" | "if" | "io" | "pf" | "debug" | 
               "proc" | "mbuf" | "sensor"
host         = ip4addr | ip6addr | hostname
port         = [ "port" | "," ] portnumber
argument     = number | interfacename | diskname
.fi
.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), 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.
.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. 
.Sh AUTHOR
Willem Dijkstra <wpd@xs4all.nl>. Daniel Hartmeier <daniel@benzedrine.cx>
contributed the pf probe and helped to port to big-endian architectures.
.Sh SEE ALSO
.Xr symux 8