nws_sensor - sensor for the Network Weather Service

nws_sensor [-c yes/no][-a addresses][-n name][-N host][-M host][-e file][-l file][-i file][-p port][-v level][-fV][-x port][-m yes/no][-A yes/no][-S yes/no][-P password][-j clique][-F]

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.

-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.

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.

Bugs list is at http://nws.cs.ucsb.edu.

NWS is an original idea of Rich Wolski (rich@cs.ucsb.edu) who wrote the orignal nws_sensor.

Neil Spring, Jim Hayes (jhayes@cs.ucsd.edu) and Martin Swany maintained and enhanced it.

Graziano Obertelli (graziano@cs.ucsb.edu) currently maintains NWS and wrote this man page.

nws_memory(1), nws_search(1), nws_nameserver(1), nws_extract(1)