| 1 | Larvnet is the cluster monitoring system which gathers the data |
| 2 | returned by the "cview" command--a list of free machines of each type |
| 3 | in the Athena clusters, and a list of the number of current jobs |
| 4 | pending on Athena printers. |
| 5 | |
| 6 | When a user logs in or out of an Athena machine, or when an Athena |
| 7 | machine starts up the login system, the machine sends a status packet |
| 8 | to the Larvnet server. The status packet gives the machine's name, |
| 9 | host type, and an determination of whether any user is logged into the |
| 10 | machine at the console. Workstations can also be queried for the same |
| 11 | status information using the "busyd" UDP service, which runs out of |
| 12 | inetd. The Larvnet server separates machine names into clusters |
| 13 | according to a configuration file and produces a data file once per |
| 14 | minute containing counts of the free machines in each cluster of each |
| 15 | type. |
| 16 | |
| 17 | The Larvnet server also queries the print spooler for each Athena |
| 18 | printer once per minute, using an "lpq" query. (Sadly, the output |
| 19 | returned by "lpq" is not standardized well enough to be robustly |
| 20 | machine-readable, so the mechanism here sometimes requires maintenance |
| 21 | when changes are made to the printing system.) |