Windows 2000 Print Job Priority Scheduling

Microsoft Windows 2000 manages print traffic through its modular Print Spooler architecture, organizing competing print tasks using a numerical priority scale ranging from 1 to 99. When multiple jobs wait in a queue, the spooler evaluates priority values first, sending the highest-priority job to the physical printer before lower-priority tasks. This mechanism allows administrators to optimize device availability, enforce user hierarchies, and ensure urgent documents bypass standard workloads without interrupting active hardware operations.

The Priority Scale (1 to 99)

Windows 2000 assigns every print job a numerical priority value:

  • 1 represents the lowest priority (the system default for standard users).
  • 99 represents the highest priority.

Users with appropriate administrative permissions can manually adjust the priority of an individual document in the print queue properties. Additionally, administrators can configure priority at the logical printer level.

Scheduling Logic and Evaluation

The Windows 2000 Print Spooler service (spoolsv.exe) and the local print provider (localspl.dll) govern job scheduling according to specific rules:

  1. Numerical Precedence: When a printing device finishes a task and becomes idle, the spooler queries the print queue for the job with the highest numerical priority.
  2. First In, First Out (FIFO) Tie-Breaking: If two or more documents share the same priority level, the spooler processes them chronologically based on the time they were submitted to the queue.
  3. No Active Preemption: Windows 2000 does not interrupt or preempt a job that is already transmitting or actively printing. Even if a job with a priority of 99 arrives while a priority 1 job is printing, the active job will complete fully before the higher-priority job begins.

Multiple Logical Printers for One Physical Device

Because standard users typically lack the permissions required to raise their own job priority, Windows 2000 handles group-based priority scheduling by mapping multiple logical printers to a single physical print device (or port):

  • Configuration: An administrator creates two distinct printer objects pointing to the same printer port.
  • Priority Assignment: One printer object is named "Standard Print" and configured with a priority of 1. The second is named "Urgent Print" and assigned a priority of 99.
  • Access Control: Windows 2000 Access Control Lists (ACLs) are applied to the printer objects. Standard users receive access to the priority 1 printer, while priority users (such as managers or specific departments) receive permissions for the priority 99 printer.

When both queues feed into the same print port, the spooler merges the requests internally and always yields port access to jobs sent through the higher-priority printer object.

Spooling State Considerations

Job priority only applies once a job is ready to print. The spooler's behavior is influenced by the printer's spool settings:

  • Start printing after last page is spooled: The job enters priority evaluation only after the client completely finishes rendering and transmitting the entire file to the spool folder.
  • Start printing immediately: The spooler can begin sending data as soon as the first page renders. If a high-priority job begins spooling under this setting, it can take the next available slot ahead of fully spooled lower-priority jobs, provided the physical printer is ready to accept a new data stream.