IBM Tivoli Composite Application Manager for Application Diagnostics, Version 7.1.0.1
Server Availability graph does not correctly account for offline servers
The problem: The % Available graph within the Server Availability report does not take offline servers into account. The first graph always reports 100% availability, but when you drill into it, several of the servers are offline and are reporting 0% availability in the detail graph.
The reason: ITCAM for WebSphere is application-centric, not server-centric; thus it takes an application-centric view of availability. When requesting a Server Availability report on All Servers, all servers in the group must host the same application and be clustered or load-balanced. Otherwise, the report will not make sense.
If any server is available, the application is considered available. Conversely, the application is considered unavailable only when all servers in the group are unavailable. Therefore, if any server is 100% available during the time period being monitored, the availability of the group will be 100%.
Example #1: Four servers in a group are clustered, and during the time period requested, three of them are always unavailable while one of them is always available. The availability will be reported as 100%, since users always had access to the application (through the one server that was always available).
Example #2: Four servers in a group are clustered, and during the time period requested, all servers are available for 75% of the time. Then all become unavailable for 25% of the time. The availability will be reported as 75% since 25% of the time the application was totally unavailable.
Parent topic:
Run the Managing Server