WebObjects Monitor Example -- v. 3

Title: WebObjects Monitor Example -- v. 3 
Entry Number: 2496
Creation Date: February 2, 1997
Last Updated: <<Date June 17, 1997>>
Procedure Valid for Release: WebObjects 3.x

Keywords: WebObjects, Monitor, Administration, Distributed Objects, Failover, Load Balancing

Overview

The WebObjects Monitor is an example that ships with WebObjects 3.0.  This NeXTanswer provides a new version of the Monitor that addresses bugs and adds several new features relative to v. 1 which shipped on the WebObjects 3.0 CD.

This NeXTanswer will explain how to install the Example in its most basic configuration.  For detailed instructions and more information about capabilities, see the HTML read me file included in the downloadable package.

Procedure

The WOMonitor package is 2497_WOMonitor.woa.compressed (450K).  If you are downloading it under NEXTSTEP, double click on the file and the Workspace will decompress it for you.  If you are downloading it under Windows, rename the file to WOMonitor.tar.Z, and unpack it by typing the following at a DOS prompt:

gunzip WOMonitor.tar.Z
gnutar xvf WOMonitor.tar

If you are running on Windows NT, all the executables are already built for you.  If you are on a Unix system, you will have to cd into the folders underneath Monitor.woa named _Monitor, _MonitorApp, and _MonitorProxy and type make for each one.  Once you have the executables for your target OS you may begin the installation.

Pre Set-up 

1	Shut down any running instances of WODefaultApp, any compiled WOF Apps, and make sure any instances of the WebObjects CGI program are shutdown.

2	It is recommended that you delete all versions of the WebObjects.conf file from your system.  In addition to your Scripts or cgi-bin folder, a WebObjects.conf file used for WOF autostarting is also located in the folder pointed to by your TEMP environment variable such as C:\Temp on NT or often /tmp on Unix.

3	Delete the previous version of the Monitor by removing the Monitor.woa folder from underneath your WebObjects Examples folder.

4	If there is a WOMonitorPreferences.conf file in your Monitor.woa folder, delete it.

5	Once you have untarred and unzipped the Monitor package that you downloaded from this site, place the Monitor.woa folder under your WebObjects Examples folder.  

6	Copy the WODefaultApp in /Monitor.woa/_MonitorApp into <NEXT_ROOT>NextLibrary/Executables.

Configure for Your Site

1	Open a command shell and cd into the Monitor.woa application folder.

2	Launch the Monitor application by typing:  "Monitor -d <DOC_ROOT> Examples/Monitor" (or "./Monitor -d <DOC_ROOT> Examples/Monitor" if you are on a Unix system).  Where <DOC_ROOT> is replaced by the appropriate document root for your site such as C:\InetPub\wwwroot if you are using IIS or PWS.

3	Goto your web browser.  The Monitor looks best in IE 3.0.  Enter the URL to the Monitor application as you would for any other WOF app: e.g.  http://localhost/Scripts/WebObjects.exe/Examples/Monitor.  If you are on a 800x600 resolution monitor, you will want to maximize the browser Window so you'll be sure to notice all of the Frames the app uses.

4	You should initially see three Frames including one containing a log-in prompt.  Click the Login button.  This opens up two more Frames.  Click the button labeled "Options" under Main Menu.  This opens up the Options inspector in the right Frame.  Under Options you will customize the Monitor's preferences to your site's environment.
  
5	If launched properly, the Options Inspector should have default values for all fields except the Admin password fields which are blank.  If you only have one HTTP server, use the same WebObjects.conf file path for both the public and private WebObjects.conf files.  Edit the default document root path if necessary for your site.  Finally, edit the fields under "Convenience App Starting" to reflect the web protocol, adaptor key, and host your HTTP server used to launch applications from your location (e.g. "http", "Scripts/WebObjects.dll", and "localhost" respectively).   When done, press "Update Environment."

6	Click "Add..." from the Main Menu to bring up the Add Application panel.  As a first time user, click the "Create Convenience Apps" button.  Only use this button when configuring from scratch.  If you use it after adding more applications, you can corrupt the WebObjects.conf file. (If that happens, you can always delete The WebObjects.conf file  and create a new one by re-using this panel.)

At this point you should be able to use the Monitor as your WOF app launch pad and configuration/load balancing center-of-operations.

See Also:

Be sure to read the WOMonitor.html Read-Me file included with the downloadable package.  It will give you more information about how to use the Monitor once installed for administration and development.  

Other features of the WebObjects Monitor include:
	- Instance removal, addition, and configuration
	- Remote machine application instance launching
	- Application removal and addition
	- Instance fail-over (The Monitor watches instances and restarts them if they fail)
	- Monitor self-failover  (The Monitor can Monitor itself and step-in if a previous instances fails)
	- Application instance scheduling including cycling and future date based starting and stopping
	- Performance statistic display, summary, and detail
	- Remote logging API
	- "Super" Application Scope data API
	- Auto-refresh monitoring controls and configuration