Tenable.io considers the following three types of scanner capacities when distributing scans, in order to efficiently determine how many tasks a scanner can process.
- Target Capacity: The number of assets a scanner can actively scan simultaneously. This value is by default based on the hardware resources of the scanner, including the number of processors and the amount of memory available.
- Task Capacity: The number of tasks (parts of a scan) that a scanner can perform simultaneously. A scanner's task capacity is determined based on the target capacity.
- Job Capacity: The number of different jobs a scanner can include tasks from at once. In this way, scans can be performed asynchronously, and a scanner that has available capacity can complete multiple tasks even if those tasks are not derived from the same scan. Job capacity is always determined to be less than equal to the task capacity so that when a scanner is at its job capacity, it will be able to complete tasks from every job.
Scanner Group Capacity
Tenable.io also considers scanner group job capacities when distributing scans. Jobs at the scanner group level are broken down into tasks when there is available capacity. Tasks from those jobs can then be divided among the scanners in the group.