NISWUP: Novell Info System Web Update Package

Status of
enterprise-wide
Novell servers
on a
Web page

name of servers currently down
name of servers currently up
login ID of users logged into each server
full name of users logged into each server
amount of total user disk space on each server
can block out: selected servers, selected users
interfaces to: email to user, finger info of user

The package consists of four applications: the Collector, the Client, the Server, and the Applet:

NISWUP Collector: reads information from Novell bindary and stores info in a text file
NISWUP Client: retrieves text file, filters out server and user names and sends info to NISWUP server, line by line
NISWUP Server: receives information from Client, stores server information in one summary file, and user info in one file per server.
NISWUP Applet: reads information from file and displays interactively on Web page. Interfaces to mail and finger, if possible.

Collector and Client run on Windows 95 or NT machine, every XX minutes. Server is a stand-alone program, running on Web server continuously waiting for client connection. Applet is part of a Web page and runs 'on demand'

The Collector

The collector is program that reads information from the Novell bindary and writes it to a text file in the following line-by-line format: 

    Type      Description
    ----------------------------------------------
    String    Current day, month, and year
    String    Current hour and minute 
    int       Number of file servers up
    String    First file server name
    long        maxDisk  = max. number of bytes on user-accessible volume
    long        actDisk  = number of bytes used on user-accessible volume
    int         maxUsers = max. possible users on server 
    int         actUsers = number of currently logged in users
    String        user name 1
    String        full name of user1
    String        ethernet address of user1
     ...              ... repeat for all users ...
    String    Second file server name
    long        maxDisk  = max. number of bytes on user-accessible volume
    long        actDisk  = number of bytes used on user-accessible volume
    int         maxUsers = max. possible users on server 
    int         actUsers = number of currently logged in users
    String        user name 1
    String        full name of user1
    String        ethernet address of user1
     ...              ... repeat for all users ......        
     ...     ..................................................
    ...    repeat for all file servers and users ...

The Collector should have a 'timing' option so that it repeats creating this file every XX minutes. Note that this timing option is not important, as there are plenty of 'scheduling' programs around for Windows 95 and/or Windows NT. However, it would be nice if the Collector had that feature built in. The collector does not need to worry about blocking out any server or user names.

The Client

The client is a Java program that runs on the same machine that the Collector runs on. It reads the data file created by the Collector, filters out names of servers and users, if necessary, and sends the remaining information through a socket to the server. It also adds the information about any servers currently down.

The client needs to handle four files; the first three are configuration files and will remain relatively static. They can be created with any text editor; the last file is the one created by the Collector every XX minutes.

Server Names The name of the host where the Server runs
The port through which client and server should communicate
A list of all Novell file servers on the entire system
Blocked Server A list of server names that should not appear on the list of UP or DOWN servers. Information for these servers is not to be transmitted, and the number of servers up and down is to be adjusted accordingly.
Blocked Users A list of user login ID's that should not appear on the list of users logged in to a system, whether they are actually logged in or not. Information for these users is not to be transmitted to the server, and the number of users on each server must be adjusted accordingly.
Server Info This is the file generated by the Collector. All information is to be sent to the client, with the appropriate servers and users filtered out and the numbers adjusted accordingly.

The Client has to agree with the server on the format in which the information will be transmitted. As a minimum, client and server should exchange some identification strings. Here is a suggestion: 

   client: establishes connection to server
   server: sends server ID string
   client: if unknown ID string, client closes. Else, send password
   server: if unknown password, server closes. Else, send 'ok'
   client: send number of servers (blocked servers subtracted)
   client: send server name
   client: send server info (disk space, users, and user info)
      .........
   client: send 'bye'
   server: closes

The Client and Server should strive to make data transmission as fast as possible. However, as a beginning, a line-by-line transmission is good enough.

The Server

The Server is a Java program running on the same Unix machine where the Web server is installed. It listens on a particular port for a client connection, and then handles the client information according to a protocol (see above for a sample protocol). The port to listen on should be a command line option.

All information received from the client should be stored first in memory. Once transmission is over, the server should create the following files, named exactly as indicated. Note that the server should try to generate each of these files as fast as possible. Maybe a 'buffered output stream' would be useful, that is not flushed too often.

The server should run as a restricted user with few rights on the system. In particular, the only area where that user has 'read/write' access should be the directory of the data file location.

The server must create the following files, in a directory named ServerData. That directory must be within the DocumentRoot of the server, but only the restricted user that the server pretends to be should have write access to it. Of course, the wmaster user need read access to those files - but not write access.

File Name File Format By Line
00Servers.dat 
String    date
String    time
int       number of DOWN servers (could be 0)
String    name of DOWN server1 (none if all are up)
   ...  all remaining names of down servers ...
int       number of UP servers (could be 0)
String    name of UP server1
long      max. disk space (no leading blanks)
long      act. disk space (no leading blanks)
int       max. users (no leading blanks)
int       act. users (no leading blanks)
    ... repeat for all servers ...
SERVERNAME
name of server in capital
letters, no extension		 
int       number of users
String    user1 ID
String    user1 full name
String    user1 ethernet address
  ... repeat for each user ...

Note that the server should also reset every file for each down server by setting placing a zero in the first (and only) line.

For now, don't worry about which user name the server runs under, as long as you have write access to the ServerInfo directory.

The Applet

Already written - which is why it is essential that the above specifications are met exactly !

The applet consists of several objects, of which only one is essential. We will discuss all details of this applet during our next class.