This manual page explains the
nws_sensor
program. The
nws_sensor(1)
is part of the Network Weather Service. A
nws_sensor
can monitor CPU activity, available memory, network bandwidth and network
latency.
We recommand that the
nws_sensor
be registered with a
nws_nameserver(1)
and that measurements be recorded by a
nws_memory(1)
A
nws_sensor
starts measuring CPU activity only when initialized. The network bandwidth
and latentcy measurements apply to a
clique
, which is composed of multiple
nws_sensors.
See
start_activity(1)
for details on how to configure a clique.
Available memory measurements are initiated by
start_activity(1)
as well.
OPTIONS
-c yes/no
Specifies whether or not the sensor should immediately begin monitoring
CPU availability for nice 0 processes (the cpuMonitor skill). Default is
yes.
-A yes/no
Starts the availability monitor right away. Default is no.
-S yes/no
Starts the start monitor right away. Default is no.
-m yes/no
Specifies whether or not the sensor should immediately begin monitoring
free memory (the memoryMonitor skill). Default is no.
-j cliquename
Try to join the running clique
cliquename
which is registered with our nameserver. The clique leader needs to be
reachable. If
-F
is specified, a clique is created if it doesn't exists already with the
nameserver.
-F
used in conjunction with
-j
force the start of a clique.
-a addresses
Specified a comma separated list of addresses (IPs or name) that the
sensor will consider be aliases for the localhost. Used for multihomed
machine when DNS doesn't return all the IPs associated with a name. These
addresses will be the first one in the private address list of the
sensor.
-n name
Use
name
as hostname. Useful the resolver aren't correctly configured and
gethostname doesn't return a resonable value.
-f
Don't fork to run an experiment. If you specify no-forking the sensor may
become less responsive since it may spend sometime doing experiments
instead of responding to messages.
-x port
Use
port
during network experiment when needed. Usually this is needed when the
buffer requested is of a different sizes than the default and a new port
is required to conduct the experiment: if behind a firewall you can
specify this option and instruct the firewall to open
port.
-e file
Save the error messages to
file.
-l file
Save the log messages to
file.
-i file
Write pid to
file
-M nws_memory
Specifies the
nws_memory(1)
that the sensor should use to store its
measurements. This overrides any default value from the environment or
~/.nwsrc.
-N nws_nameserver
Register this nws_sensor with
nws_nameserver
-V
Prints the version.
-P password
User will need
password
to control this sensor.
-p port
Listen to port instead of the default for the nws_sensos (8060).
-v level
Set the verbosity in case of error. Value of
level
can be 0 to 5 where 5 is the more verbose.
BUGS
If the machine is behind a firewall (with or without NAT), the
nws_sensor
may get confused when talking with other part of the NWS.