After applying RU9 or above roll up patches (RU12) for 17.2 the default configuration of health servlet for load balancer is no longer working.
1. For Service Desk 17.2 apply RU9 or above RU12.
2.The default steps to configure are mentioned are as below:
"Navigate to Local Traffic, Monitors, and Click Create. Complete the following field information:
Name: Enter the name of the health monitor.
For example: SDM_health
Type: Select HTTP from the drop-down list.
You must base each custom monitor on a monitor type. To specify a monitor type, simply choose the one that corresponds to the service you want to check.
Send String: Enter GET /HealthServlet/GetHealth\r."
# The steps as per documentation are working fine until RU8, after applying RU9 and above it is no longer working.
3. With "String: Enter GET /HealthServlet/GetHealth\r" loadbalancer is not reaching applications.
The change that is probably affecting the behavior due to the Tomcat upgrade. The Tomcat has been downgraded from version 8.5.6 to 8.5.53.
There has been a known vulnerability with tomcat 8.5.6 which is addressed in DE53936.Please refer to below doc on same:
Hence tomcat version has been updated.
Release : 17.2
Component : SERVICE DESK MANAGER
This has been discussed with SE via defect DE59664.
By default for F5 loadbalancer HTTP version is defined as 0.9, kindly change the HTTP version to 1.0 and update as below:
"GET /HealthServlet/GetHealth HTTP/1.0\r\r"