Spooler Utilities Reference Manual

Introduction to the Spooler Subsystem
Spooler Utilities Reference Manual—522295-003
2-7
Spooling in a Network
Unit Size
The Spoolcom COLLECT UNIT command is used to specify a unit size for the
collector. The unit size specifies the number of 512-word blocks the collector allocates
from its data file each time it needs more space for a job. A collector can manage as
many units as a physical file will hold.
The larger the unit size, the less often the collector must allocate a new unit. Thus, you
could specify a relatively large unit size if you expect that most spooled jobs will be
large. You could also use a large extent size if using large block sizes.
A smaller unit size provides more efficient use of disk space, because once the
collector reserves space for a job, that space cannot be used by any other job. If the
unit size is 10 and a spooled job requires only 1 block, the other 9 blocks are wasted.
You should set the unit size of a collector once and not change it. If a different unit size
is required, delete the old collector and start a new one.
The ability to specify different unit sizes with different collectors is consistent with pre-
D41 spoolers. However, for the D41 and later releases of the spooler, HP recommends
a unit size of 4K bytes and a DP2 buffer size of 4K bytes, unless jobs are likely to be
less than 2K bytes in length. The spooler is most efficient when 4K values are used,
but if jobs are generally less than 2K bytes, a 2K setting for both unit size and buffer
size will yield about the same performance and be more efficient in the use of disk
space. Note that 2K bytes is the minimum value you can specify for buffer size.
Spooling in a Network
Spoolers can be linked in a network such that applications on one node can have their
jobs printed on another node with the spooler managing the print-job transfers across
the network. The link between network spoolers is illustrated in Figure 2-2. On the
application node \APPL, applications send print jobs to their local spooler. The spooler
is configured to have the FASTP print process control the transferring of print jobs to
the remote node \PRNT, where the actual printers are located. The print process
controlling the printers could be any spooler-supplied or user-written print process.
For information on managing networks linked as illustrated in Figure 2-1, see
Section 6, RPSetup Utility
.