Network Weather Service

Frequently Asked Questions

• How do I build NWS?
• I built it, and now?
• Where can I find documentation on the command line arguments?
  
• I don't know how to do X and it's not in the man pages!
  
• I want pretty graphs!
  
• Cannot start the nameserver/memory/sensor
  

How do I build NWS?

In short:

tar xf nws-3.xx.tar
cd nws-3.xx
./configure --prefix=/some/place/to/install/NWS/binaries
make install

and you are good to go. If you don't want to install it there will be a directory in the source tree called build-architecture where architecture will be what autoconf detected on you machine, and under that directory there is a bin directory with all the binaries. You can run them from there.

There are options that you can pass to the configure script notably --enable-debug (enable debug symbols during compilation), --enable-threads adds locks to the NWS library to be used with threaded programs (note: NWS is not threaded, this is only for program accessing the NWS API), --disable-sigalarm don't use SIGALARM and --enable-nonblocking use non blocking sockets (the last 2 should be better used in pairs, since disabling the use of SIGALARM can block NWS daemon indefinetely on system calls).

I built it, and now?

Congratulations, you got NWS compiled. The things you need now is to pick a reliable host, possibly with some disk space if you will have a lot of sensor and you can start the nws_nameserver and nws_memory on it. You don't need to start them on the same machine at all, but sometimes it's easirt to remmeber one hostname for small installation. You can then start as many nws_sensor on as many hosts you want to monitor: after few seconds you can use nws_extract to start getting CPU data out of the memory (CPU measurement are started by default).

Where can I find documentation on the command line arguments?

There is Doc folder shipping with the NWS sources and some html documents that is badly outdated: don't use it too much! We have man pages for all the commands (you can spot them in the source tree by the command name with a number added at the end). If you installed nws you'll find the manpages under the

<installDir>/man

To read them, at least on linux, you can use

man -l <filename>

where the -l instruct man that it's a local file.

I don't know how to do X and it's not in the man pages!

You can write on the nws mailing lists.

Cannot start the nameserver/memory/sensor

One of the most common problem is that the port is already in use. You can use netstat to check if the needed port (defaults are 8060 for the sensor, 8050 for the memory and 8090 for the nameserver) is taken or not. On some system the abrupt killing of a daemon using that port can results in a timeout period for which no other process can take up that port. You can use the -p switch to instruct every NWS process to use a different port, and NWS understand a hostname:port to address a NWS daemon on a non-standard port (for example if the nameserver is running on port 1234 you can use -N hostname:1234 on the command line for the sensor).