Does a datadog agent generate metrics? How does it collect metrics that the host's app generates? Does it intrude the app code environment to collect metrics?
Let's say that the app is a Spring Boot app. It has a set of metrics already being generated by Micrometer and is exposed on the /metrics endpoint. How does a datadog agent fit in, here?
Let's say that the app is the same this time. But, does not have micrometer enabled. How would datadog fit in here?
Would it have the capability to generate metrics from this app? If so, how does it do the same? Furthermore, in doing so, does it access the application's source code? Or gets into the runtime and adds bytecode to generate metrics by observing the events?
Let's say that, we have an application running on the host, that already generates metrics and can ship it to a network accessible storage. Can datadog be used just to collect the data and visualize it? Without an agent? Does datadog only collect metrics that are exposed by the host's app?
The reason I am curious to know these aspects is to analyze the vulnerability of the host with this respect, understand the added overhead in terms of infrastructural resources, understand the performance overhead and the cost involved. At the same time, a stronger question that stands is, why datadog?
Any thoughts on Dynatrace in the same respect?
