Hi Jhancock,
Please see our inline answers to your queries.
1)I'm wondering what possible performance impact the agent has on our production IIS services. We would use the software mostly for troubleshooting, not for constant monitoring.
=>
It depends on application. Typically <2%. There is not such thing as diagnostics/monitoring mode. AppDynamics is designed to work in production with minimal overhead when tuned correctly for the specific application.
2)Is the agent always running and collecting data, even after I select "Stop .NET Lite Viewer" (which I'm guessing only stops the website we use to browse the UI)
=> Yes, the agent always run and collects data. If you stop .Net Lite Viewer it will stops only the Viewer UI.
3) If it's always running, can I stop the agent and then restart it when I need to monitor, without having to restart IIS?
=> Yes, we can stop the instrumentation but it requires IIS reset.
Steps to disable the App Agent:
i) Setting the AppDynamics system level environment variable : COR_ENABLE_PROFILING to 0, also setting COR_PROFILER to a string other than 'AppDynamics.AgentProfiler' (e.g. set it to _AppDynamics.AgentProfiler instead of AppDynamics.AgentProfiler).
ii) Disabling the 'AppDynamics.Agent.Coordinator' service
iii) Recycling the instrumented AppPools (or IIS if that is an option).
3) Does the application keep IIS connections open, i.e. especially for the BTs showing in the Viewer? IIS needs to close connections as soon as the web request is done, so that other incoming requests can be serviced.
=> No, we do not control IIS in any way. We just hook into the IIS process and instrument it.
Thanks,
Venu.
