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NWD, or New Wheel Daemon, named for its status as a likely reinvention of the wheel, is a script used on our campus to monitor the CPU, memory, and network loads of ACL machines, including the number of open displays and the number of displays it has committed to serve. It serves a crucial function in helping Chooser loadbalance. It was created by members of the Pedagogical Tools Group under the supervision of Computer Science professor James Rogers, but its authorship slot was left blank. Its contents can be viewed below.

Script Contents

.TH "NWD" 8 .SH NAME nwd \- New Wheel Daemon

.SH "DESCRIPTION" .PP NWD monitors the CPU, memory, and network loads for a given machine, and keeps track of the number of open displays, as well as the number of displays it has committed to serve. .PP NWD performs logging in /var/log/nwd/ .SH "INTERACTING WITH NWD" Remote hosts can interact with NWD by sending UDP packets to port 49177, the list of packets NWD responds to are as follows:

\fBr <display>\fP .PP Make reservation for <display> where <display> is X displayname .PP \fBx <display>\fP .PP Cancel reservation for display .PP \fBs <display>\fP .PP Select reservation for display. Reservation wil persist for SELECT_TIME seconds. It is assumed that <display> will become actively managed within that interval .PP \fBq\fP .PP Queries acl and returns <active displays> <reserved displays> <enabled> .PP \fBb\fp .PP Makes acl block new connections .PP \fBu\fP .PP Makes acl accept new connections .PP \fBc\fP .PP Clear all reservations on acl .PP We recommend using the nwclient.pl utility for manual interactions with NWD


.PP nwclient.pl, chooser.c, chooser_wrapper_xdm, setupchooser.sh


.PP Do we have a version number for this? Remove this?


.PP \fBnwclient