---
name: "nws_start_activity"
section: "1"
platform: "linux"
package: "nws"
version: "2.13-6.1"
release: "Debian 5.0 (Lenny)"
platforms: ["linux"]
url: "https://new.carta.tech/nws_start_activity"
---

# nws\_start\_activity(1)

instructs the Network Weather Service to start monitoring resources

## NAME

start\_activity - instructs the Network Weather Service to start monitoring resources

## SYNOPSIS

**start\_activity** \[-F\]\[-a\]\[-f file\] host \[attribute:value ...\]

## DESCRIPTION

This manual page explains the  **start\_activity** program. You can start to monitor resources using **start\_activity** and you can use  **halt\_activity(1)** to stop the monitoring.

**start\_activity** contacts a  **[nws\_sensor(1)](/nws_sensor/1.md)** running on *host* and instructs it to start the activity specified by  *attribute:value.* Here is a list of attribute you can specify (is not complete)

**name**

specifies the unique name that specifies the activity to be started. If you don't specify one, an automatic one will be generated.

**skillName**

specify the resource that can be monitored (cpuMonitor, diskMonitor, memoryMonitor, tcpConnectMonitor, tcpMessageMonitor)

**controlName**

specify the control that is ultimately responsible for how frequently measurements are taken.  **periodic** and  **clique** are the allowed values: the former takes one host measurements (cpuMonitor) and the latter takes care of the multiple host measurements (tcpMessageMonitor)

**member**

specify a host that is part of this clique. Tipically you will have at least 2 of these options. You can specify members with the  *host:port* format. Currently there is a limitation of 100 member for a clique.

**period**

specify how many seconds between measurements.

**size**

specify the size of the experiment to be conducted (valid only for 2 hosts experiments like bandwidth experiment). This is the  **total** number of kB sent for a single experiment (default is 64 for versions 2.6 and smaller, 256 for the others).

**message**

specify the size of the messagei (measured in kB)  to be used during network experiments. It cannot be bigger then what specify by  *size.* Default is 16 kB.

**buffer**

specify the buffer to be requested when opening a socket to conduct a network experiment (measured in kB). Not all systems allows the user to change this value: NWS will revert to what is allowed in this case. Default is 32 kB.

You can see  **EXAMPLES** later on for a simple example.

## OPTIONS

- **-F**

  **force the**  **nws\_sensor** to start the activity even if a record still exists in the  **nws\_nameserver**

- **-a**

  restart all activities on this host

- **-f file**

  read attribute:value from *file* instead of the command line.

## EXAMPLES

Let's suppose we have few machines already running **[nws\_sensor(1)](/nws_sensor/1.md)** and that we want these nodes to begin performing measurements (of latency and bandwidth in this example). Let A, B and C be three such hosts. You can create a configuration file that defines this situation and then execute start\_activity to refer to this configuration using the -f switch. Here is a sample configuration file:

name:pippo

controlName:clique

skillName:tcpMessageMonitor

member:A

member:B

member:C

size:32

period:120

This instucts the sensors to form a clique named  *pippo* whose members are A, B and C, that uses a message size of 32K and that takes measurements every 120 seconds. The command line will be

**start\_activity** -f  *file* A

## BUGS

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

## AUTHOR

NWS is an original idea of Rich Wolski Rich Wolski (rich@cs.ucsb.edu) who came up with the original **nws\_memory.**

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.

## SEE ALSO

**[nws\_sensor(1)](/nws_sensor/1.md),** **[nws\_search(1)](/nws_search/1.md),** **[nws\_nameserver(1)](/nws_nameserver/1.md),** **[nws\_extract(1)](/nws_extract/1.md)** **halt\_activity(1)**