Application Load Manager Reference

The Application Load Manager is available for OS/390, UNIX, and Windows systems. The Load Manager executable (loadmgr.exe on Windows, loadmgr on other platforms) is included in the CGI Tools for Web Server package. After you have installed this package, you can find the Load Manager executable in the Web server directory corresponding to the URL

   http://yourserver/sasweb/IntrNet8/tools

The Load Manager executable is also included in the SAS system installation on UNIX and Windows systems. The Load Manager can be found at the following locations:

UNIX: !SASROOT/utilities/bin/loadmgr
Windows: !SASROOT\intrnet\sasexe\loadmgr.exe

Starting the Load Manager

The syntax for starting the load manager is

loadmgr <options>

where <options> can be any of the following:

-delete: removes a previously installed load manager as a system service on Windows NT.
-install: installs the load manager on Windows NT as a system service.
-log<=filename>: specifies an optional log file. The STDOUT device is used if a filename is not specified.
-passwd<=password>: specifies an optional password controlling access to the ENDLOADMGR and LOADSTAT administration programs. If the -passwd option is specified without a password value, a prompt is issued for the password.
-port=nnnn: specifies the port number or service name for the socket on which the Load Manager listens. If this parameter is not specified, the /etc/services file is checked for an entry for LOADMGR.

On Windows platforms only, a setup wizard is available to configure the Load Manager. The setup wizard allows you to create Start menu shortcuts to start the Load Manager, install or uninstall the Load Manager as a Windows service, or view log files. See Load Manager on Windows Platforms for more information.

Stopping the Load Manager

The Load Manager can be stopped from a Web browser. The URL depends on the platform and path where your Application Broker is installed. For typical installations, the URL to stop a service is one of the following:

Windows: http://yourserver/scripts/broker.exe?_service=service-name&_program=endloadmgr
UNIX and OS/390: http://yourserver/cgi-bin/broker?_service=service-name&_program=endloadmgr
CMS: http://yourserver/sasweb/htbin/broker.cgi?_service=service-name&_program=endloadmgr

Specify your Web server name in place of yourserver and any service that uses the Load Manager in place of service-name. You might need to use a different URL path if you chose a different path when you installed the Application Broker. The ENDLOADMGR command also stops any pool service Application Servers that have been started by the Load Manager. If the load manager was started with the -passwd option, the specified password must be appended to the URL. For example:

   http://yourserver/scripts/broker.exe?_service=service-name&_program=endloadmgr&_passwd=secret

Broker Directives for the Load Manager

To use the Load Manager, add a directive to the Broker configuration file:

   LoadManager host:port

You can override this on a per-service basis with a corresponding ServiceLoadManager directive:

   ServiceLoadManager host:port

No other changes are required. All information in the Broker configuration file are passed to the Load Manager by the Application Broker as needed.

Load Manager Statistics

Statistics are recorded for all Application Servers requested through the Load Manager. Data is kept for the length of jobs and for the amount of time required to wait for a server. The job times are based on state changes sent from the Application Servers and vary slightly from the job times reported by the Broker.

A statistics report may be obtained by running a special program via the Broker. The load manager statistics are returned when _PROGRAM is set to LOADSTAT and _SERVICE specifies any service that uses the desired load manager. If the load manager was started with the -passwd option, _PASSWD must be used to supply the password. For example, the URL

   http://yourserver/scripts/broker.exe?_service=default&_program=loadstat&_passwd=secret

might return the following report:

Load Manager serv.abc.com:5555

Service default
Server	Port	Total Jobs	Max Job Time	Average Job Time	Percent Waited	Average Wait Time
serv.abc.com	5197	2	0.52	0.38	0.00	0.00

Service v8_pool
Server Port Total Jobs Max Job Time Average Job Time Percent Waited Average Wait Time

poolserv.abc.com 2909 12 10.40 2.20 10.00 1.79
poolserv.abc.com 2940 1 0.08 0.08 100.00 0.19

The columns of the report are defined as

Server: is the Application Server host.
Port: is the port number for the Application Server.
Total Jobs: is the number of complete Broker requests that were processed.
Max Job Time: is the length of the longest-running Broker request, in seconds.
Average Job Time: is the average length of all Broker requests, in seconds.
Percent Waited: is the percentage of Broker requests that had to wait for an Application Server.
Average Wait Time: is the average amount of time, in seconds, that a Broker request waited, if it had to wait.