Enabling Load Balancer Logging

The load balancer plug-in logs the following information:

• Request start/stop information for every request.

• Failed-over request information when the request fails over from an unhealthy instance to a healthy instance.

• List of unhealthy instances at the end of every health check cycle.

When load balancer logging is enabled, and if the web server logging level is set to DEBUG or to print verbose messages, the load balancer writes HTTP session IDs in the web server log files. Therefore, if the web server hosting the load balancer plug-in is in the DMZ, do not use the DEBUG or similar log level in production environments.

If you must use the DEBUG logging level, turn off load balancer logging by setting require-monitor-data property to false in loadbalancer.xml.

To turn on load balancer logging

1. Set the logging options in the web server. The procedure depends on the web server:

   • With Sun Java System Web Server

     In the server’s admin console, go to the Magnus Editor tab and set the Log Verbose option to On.

   • For Apache Web Server, set the log level to DEBUG.

   • For Microsoft IIS, set the log level to FINE in the sun-passthrough.properties file.

2. Set the load balancer configuration’s monitor option to true.

   Use the asadmin create-http-lb-config command to set monitoring to true when you initially create the load balancer configuration, or use the asadmin set command to set it to true later. Monitoring is disabled by default.