Please check the below
Tech Tip - maintenance_mode probe behavior
Below is what happens at nas during maintenance mode
interaction with nas probe
nas probe builds list of which device is in under maintenance by regularly asking maintenance_mode probe.
maintenance_mode probe provides the latest info of maintenance_window table (its end_time not expired).
when new alert is arriving at nas probe, nas probe checks dev_id (which is an attribute in alert) and if dev_id is in the list, then nas discards the alert
Could you please detail the issue which you are facing with the pre-processing rules during maintenance mode ?