Understanding Advanced Scan Prioritization

Advanced scan prioritization allows the Global Service to move a scan to a different sensor, depending on the scan priority and other settings as described in the following paragraphs.

Priority and Sensor Pools

For prioritization, scans are grouped by the sensor pool to which the scan belongs. Grouping scans by pool ensures that a higher-priority scan in sensor pool 1 will not pause a lower priority scan in sensor pool 2.

Priority and Scan Status

Scans with the following statuses are processed first from the highest to lowest scan priority and then from the oldest to newest:

Queued
Resume Scan Queued
Resume Scan Queued Scan Priority
License Unavailable
Paused Scan Priority

The following table provides examples using five scans with various statuses, priorities, and creation times.

Scan Status	Priority	Created On Date/Time	When Started or Resumed
Paused Scan Priority	0	4/26/2023 08:00 AM	Fifth
Resume Scan Queued	5	4/26/2023 08:15 AM	Second
Resume Scan Queued Scan Priority	5	4/26/2023 09:00 AM	Third
Queued	5	4/26/2023 11:26 AM	Fourth
Queued	10	4/26/2023 12:01 PM	First

Priority and Sensors

When configuring a scan, you can select a specific sensor in the Run Scan or Schedule Scan dialog boxes. You can also select the Use this sensor only option. The following table describes how these options affect advanced scan prioritization.

Selected Sensor Options	What Happens
A specific sensor is selected with the Use this sensor only option	If the sensor is available, then the scan starts on the sensor. If the sensor is not available and there is a lower-priority scan that is running on that sensor, then the lower-priority scan is paused and the higher-priority scan is started on the sensor.
A specific sensor is selected without the Use this sensor only option	If the sensor is available, then the scan starts on the sensor. If the sensor is not available, the Global Service attempts to find any other available sensor in the sensor pool. If an available sensor is found, the scan starts on that sensor. If no sensor is available, the Global Service checks whether a lower-priority scan is running. If a lower-priority scan is running, then the lower-priority scan is paused and the higher-priority scan is started on that sensor.
Any Available sensor is selected	If a sensor is available in the sensor pool, then the scan is started on the sensor. If no sensor is available in the sensor pool, the Global Service checks whether a lower-priority scan is running. If a lower-priority scan is running, then the lower-priority scan is paused and the higher-priority scan is started on that sensor.

Selected Sensor Options

What Happens

A specific sensor is selected with the Use this sensor only option

If the sensor is available, then the scan starts on the sensor.

If the sensor is not available and there is a lower-priority scan that is running on that sensor, then the lower-priority scan is paused and the higher-priority scan is started on the sensor.

A specific sensor is selected without the Use this sensor only option

If the sensor is available, then the scan starts on the sensor.

If the sensor is not available, the Global Service attempts to find any other available sensor in the sensor pool. If an available sensor is found, the scan starts on that sensor. If no sensor is available, the Global Service checks whether a lower-priority scan is running. If a lower-priority scan is running, then the lower-priority scan is paused and the higher-priority scan is started on that sensor.

Any Available sensor is selected

If a sensor is available in the sensor pool, then the scan is started on the sensor.

If no sensor is available in the sensor pool, the Global Service checks whether a lower-priority scan is running. If a lower-priority scan is running, then the lower-priority scan is paused and the higher-priority scan is started on that sensor.

When Advanced Scan Prioritization is Disabled

If the Disable Advanced Scan Prioritization option was selected in the ScanCentral DAST Configuration Tool, then when a lower-priority scan is paused for a higher-priority scan to run, the lower-priority scan resumes only on the sensor on which it was originally running, regardless to whether another sensor is available in the sensor pool. Partial scan results are uploaded to the ScanCentral DAST database, but the paused scan remains on the sensor. If the scan is resumed, but the scan no longer exists on the sensor for any reason, the Global Service downloads and imports the partial results prior to resuming the scan.

For more information, see Configuring Scan Priority.

See Also

Configuring Scan Details