1. A method comprising: building a registry of available discovery adapters; obtaining discovery data from information technology infrastructure; generating a discovery plan comprising a list of discovery adapters by matching one or more information technology resource types identified in the discovery data to information technology resource types associated with respective ones of the available discovery adapters; providing the discovery data to the discovery adapters in the list to execute a discovery run comprising the discovery adapters analyzing the discovery data and storing information on information technology resources in a discovered resources repository; and dynamically adjusting allocation of the information technology resources based on the information stored in the discovered resources repository; wherein the method is performed by at least one processing platform comprising one or more host devices implementing the discovery adapters; wherein generating the discovery plan comprises identifying scale factors used to select respective numbers of discovery adapters associated with each of the information technology resource types identified in the discovery data; further comprising dynamically adjusting the scale factors during the discovery run based on processing loads for different information technology resource types; and wherein dynamically adjusting the scale factors comprises adjusting amounts of compute, storage and networking resources of the one or more host devices allocated for different instances of the discovery adapters.