Creating spool requests takes a long time. Finally, the system cannot create any more requests and the short dump SPOOL_INTERNAL_ERROR occurs. In the dump itself and in the syslog, the system issues the message "Spool full" or "Spool overflow".
In the standard SAP system, the number of spool requests that can be created is limited to 32000. If you reach this limit, there are no more free numbers and the errors described above occur.
You can raise the upper limit for spool requests. As of Release 4.0, you can set the upper limit to anywhere between 2 and 31 numbers (previously 99,000). However, we recommend that you do not set the interval higher than 999,999 because the human user finds higher numbers difficult to process. (This is not a technical restriction; it concerns the handling only.)
Proceed as follows:
1. Log on to the system in client 000 and call transaction SNRO.
2. Select the object SPO_NUM and choose the button: Number ranges.
3. On the next screen, choose: Change Intervals.
4. In the "To number" column, change the upper limit of interval 01 to 999,999, for example.
The size of the interval also determines the maximum number of spool requests that can exist in the system. To ensure that the system performance does not deteriorate, you must use RSPO0041 or RSPO1041 on a regular basis to delete spool requests that are no longer required. The number of spool requests that can be held "officially" in the system depends to a great extent on the capacity of the database and the database computer. Only the number of spool requests simultaneously held in the system is relevant, not the size of the number intervals.
You can use the spool number monitor in transaction RZ20 to specify threshold values in which the system must create an alert if a certain percentage of the spool numbers are allocated.