Printing in Order of Generation
In an SAP System, if several spool work processes are running on a spool server or load balancing is activated, output requests can, in principle, be processed at the same time.
If load balancing is activated, then output requests for a particular device may be processed by different spool servers. Potentially, a short output request that was generated later could overtake an earlier but longer request.
Note
The spool system does allow you to enforce print in order of generation for particular output devices. To do this, on the Output Attributes
tab for the device definition, select Process Requests
sequentially. This option forces "print in order of generation" for requests for the device, even if the Spool Server
definition allows dynamic server selection. This option makes it possible to use load balancing for most of your printers, but keep print-in-order-of-generation for critical printers.
If printing in the order of generation is absolutely necessary, you must not define any alternative servers. A violation of this order can occur in the following scenario:
Example
A spool server becomes unavailable meaning that output requests are re-directed to the alternate server. Upon the reactivation of the first spool server, the server finishes an output request before the alternate server has finished with its current request.
Within a single spool server, "print-in-order-of-generation" is always observed, even if there are multiple spool work processes. The spool system allows only a single work process to work on output requests for a particular printer at any one time. Other output requests for the same printer must wait, even if other spool work processes in the server are free. This rule applies regardless of whether static server selection or dynamic selection through load-balancing or alternate servers is in effect.
