Forum Discussion
Eric_Frankenfie
Nimbostratus
NimbostratusMonitoring Individual Application Tiers
We have a web application which consists of two web servers: webserverA and webserverB. The web servers are in a pool which is assigned to a VS. Each web server is tied to its own application server and its own processing server. The web server communicates to the application server over tcp/8825 and the processing server over tcp/8925. I have been requested to mark the web server down if either the application or processing servers are down. The application and processing servers cannot be load balanced according to the third party developers.
VS >> webserverA and webserverB webserverA >> appserverA and procserverA webserverB >> appserverB and procserverB
Can and should this monitoring reside on the F5? My inital thought is to setup a monitoring service on each of the two web servers which would shut down the HTTP service in the event the APP or processing servers were down. The F5 would no longer send traffic to the web server once the HTTP service was down.
Any help would be appreciated.
shaggyI've seen this done various ways, but I think the lessor of evils is to let the web server determine if the tiers behind it are down and reflect that status by either shutting down its web-service or presenting a "down" status on a healthcheck page that the F5 is monitoring.
Another lessor-of-evils option is to create and apply an F5 monitor that sends test transactions to the web-servers. That test-transaction would need to be processed similar to real application transactions, which would allow the F5 to receive some expected response if the transaction was successful through all tiers.