Discovery probes and sensors

Discovery probes and sensors perform data collection and processing tasks.

The probe collects the information and the sensor processes it. Both get their instructions from the ECC queue. There is a worker job on the MID Server that monitors the queue for work. The monitor checks for any entries where the Queue is output and the State is ready.
Figure 1. ECC Queue Output
The MID Server then processes all the output ECC messages, runs the necessary probes, and returns the probes results to the ECC queue. These results are put in the ECC Queue as input entries.
Figure 2. ECC Queue Input

After an entry is inserted in the ECC Queue table, a business rule fires (on insert) that takes that information and runs it through a sensor processor. The sensor processor's job is to take the input data, find any sensors interested in that data, and pass it along to be processed. Those sensors ultimately update the CMDB.

For tips and instructions for creating your own custom probes and sensors, visit the ServiceNow community.