This KB explains the "Cache Results" probe option.
On Instance, Before Creating ecc_queue Record
Class Probe.java creates ecc_queue records for probes.
Before creating the ecc_queue record it checks if:
- System property glide.discovery.use_probe_results_cache = true
- Probe column cache_results = true
If both conditions above are true:
- Check if table discovery_probe_results_cache has a record for the combination of probe_id and CI sys_id
If a cache result is available it adds probe parameter PROBE_RESULTS_HASH to the probe.
On MID Server
The result of a probe is calculated into a hash. Probe post processing scripts are not processed and skip_sensor is set true if the new hash matches the old hash.
The payload is set to:
<?xml version="1.0" encoding="UTF-8"?><parameters><parameter name="snc_payload_processed" value="true"/></parameters>
Finally, the payload is returned to the instance.
On Instance When Result is Returned
Business rule makes call to AutomationEccSensorConditions which sets the input to processed if parameter snc_payload_processed = true is found in the payload.
The following error may be seen when processing the inputs if the AutomationEccSensorConditions script include is not OOB and the payload is cached:
- "No sensors defined"