I'm looking to set up my alert rules and monitoring for an ASP.Net MVC application hosted as an Azure Web App, but I am a bit unsure of the nuances of monitoring in the cloud hosted environment.
To me the alerts associated with the WebSite (be it events or based on metrics) seem equivalent with what I'd like to have with an on-premise hosted site (ie. start/stop events, server errors, requests/Http 2..4 occurrence anomalies). The exercise is standard with monitoring any web server (from my understanding).
Having never administrated a server farm, I'm confused as to what metrics/events do administrators need to be alerted on with regards to the ServerFarm? The available metric list in Azure for alert rules is: Data In, Data Out, CPU Percentage, Disk Queue Length, Http Queue Length, Memory Percentage. The available events are: delete, scale down, scale up. With regards to a server farm, when/what does ops need to be made aware of?
I think it's important to understand what a server farm is. For starters it is the same as the "App Service Plan" in the portal. What it is in practice is essentially a mapping between your worker servers and your websites within that App Service Plan, or server farm. This means that the metrics will be measured per worker server in your server farm.
If you only have one server and one site in your server farm, then these metrics would be equivalent to measuring that per site.
Thus if you were concerned about performance metrics such as high CPU use on your worker server machine you could configure an alert to notify you, or an autoscale rule to add more worker servers to serve your web site.