Printer Pooling Improvements in Windows NT 4.0 Service Pack 6

Functionality has been added to Windows NT 4.0 Service Pack 6 (SP6) to improve printer pooling in Windows NT. The following problems are addressed:

• A print job hanging on a printer in a printer pool should resume after the error condition has been resolved.
• A print job should not be sent to a printer from a printer pool if the printer is not available. (An exception is a printer status indicating a low-toner state, which is not considered an error. Even if the printer is in this state, the job is sent to the printer.)
• If the print job is not printed within a configurable amount of time, the spooler should be able to redirect the job to the next available printer in the pool.

Windows NT Server or Workstation 4.0

To resolve this problem, obtain the latest service pack for Windows NT 4.0 or the individual software update. For information on obtaining the latest service pack, please go to:

• http://www.microsoft.com/downloads/details.aspx?familyid=E396D059-E402-46EF-B095-A74399E25737&displaylang=en/ (http://www.microsoft.com/Windows/ServicePacks/) -or-
  
  
• 152734  (http://support.microsoft.com/kb/152734/EN-US/ ) how to obtain the latest windows nt 4.0 service pack

For information on obtaining the individual software update, contact Microsoft Product Support Services. For a complete list of Microsoft Product Support Services phone numbers and information on support costs, please go to the following address on the World Wide Web:

Windows NT Server 4.0, Terminal Server Edition

To resolve this problem, obtain the latest service pack for Windows NT Server 4.0, Terminal Server Edition. For additional information, click the following article number to view the article in the Microsoft Knowledge Base:

Microsoft has confirmed that this is a problem in Windows NT 4.0 and Windows NT Server 4.0, Terminal Server Edition. This problem was first corrected in Windows NT Server 4.0 Service Pack 6 and Windows NT Server 4.0, Terminal Server Edition Service Pack 6.

Two registry values have been created under the following registry key: These values can only be configured per server:

• RestartJobOnPoolError (REG_DWORD) - configures the time (in seconds) after which a job in the pool should be restarted if the port is in an error state and the error condition has not been resolved.
  Default value = 0x00000258 (600 seconds = 10 minutes)
• RestartJobOnPoolEnabled (REG_DWORD) - Determines whether a print job to a local printer can be restarted after an error.
  0 - Print jobs cannot be restarted on error.
  1 - Print jobs can be restarted on error.
  Default value = 1

To make this work, the spooler must know whether the port is in an error state. Therefore, the port monitor must update the spooler with the device status.
Some printing pools scenarios that explain the functionality include:

• The most common case is to print a job to a pool/printer that is out of paper. The time for updating the printer status is long enough that the printer buffer becomes full before the spooler determines that the port is in an error state and stops writing to the printer. Because of this, you are informed that writing to printer did not succeed. If the restarting behavior is enabled after ten minutes:
  • If you click Retry, the job is restarted after ten minutes.
  • If you click Cancel, the job is deleted.
  • If you do nothing, the job is restarted after ten minutes and the window is closed when job is restarted.
  • If the restarting behavior is not enabled, the window remains on the screen until you click one of the available options.

• If the error state persists more for longer than the time set by the RestartJobOnPoolEnabled value, the job should be restarted on another port.
• If the port is in an error state but recovers before the time for restarting expires, the job should continue to be printed on the same port.
• If Simple Network Management Protocol (SNMP) is disabled, the job stops responding (hangs) on the same port even if restarting is enabled.
• If SNMP is enabled but the printer does not support SNMP, the job hangs on the same port even if restarting is enabled.
• If SNMP is enabled but the printer turned off, the job hangs on the same port even if restarting is enabled.
• If restarting is disabled, the job hangs on the same port (the same as the current behavior).
• If restarting is enabled after a time less than the time needed for the spooler to determine the status of the device and take the proper action (this a per-port monitor setting), the job hangs until the spooler is informed of the device status and it is restarted afterwards.

If you install this fix and then upgrade to Service Pack 6, you lose all printers if you do not set the UseSoftwareHive registry setting as discussed in the article listed above.