PMDF normally creates one delivery service job per channel that needs service. This applies to both immediate service and periodic service jobs: when a message is initially sent and immediate service is needed one job is created for each channel to which the message is queued, and when PMDF creates periodic jobs it normally creates one periodic job for each channel that needs service.
A single service job may not be sufficient to insure prompt delivery of all messages, however. In particular, PMDF-FAX messages may take a long time to deliver; if multiple FAX modems are available it is not sensible to use a single job and a single modem.
filesperjob keywords can
be used to cause PMDF to create additional service jobs. Each one of
these keywords takes a single positive integer parameter which
specifies how many addresses or queue entries (i.e., files)
must be sent to the associated channel before more than one service job
is created to handle them. If a value less than or equal to zero is
given it is interpreted as a request to queue only one service job. Not
specifying a keyword is equivalent to specifying a value of zero. The
effect of these keywords is maximized; the larger number computed will
be the number of service jobs that are actually created.
addrsperjob keyword computes the number of services
jobs to start by dividing the total number of To: addressees in all
entries by the given value. The
divides the number of actual queue entries or files by the given value.
Note that the number of queue entries resulting from a given message is
controlled by a large number of factors, including but not limited to
the use of the
and the specification of header-modifying actions in mailing lists.
maxjobs keyword places an upper bound on the total
number of service jobs that can be created. This keyword must be
followed by an integer value; if the computed number of service jobs is
greater than this value only
maxjobs jobs will actually be
created. The default for this value if
maxjobs is not
specified is 100. Normally
maxjobs is set to a value that
is less than or equal to the total number of jobs that can run
simultaneously in whatever service queue or queues the channel uses.
For example, if a message with 4 recipient addresses is queued to a
addrsperjob 2 and
maxjobs 5 a
total of 2 service jobs will be created. But if a message with 23
recipient addresses is queued to the same channel only 5 jobs will be
created because of the
Note that these keywords affect the creation of both periodic and immediate service jobs. In the case of periodic jobs the number of jobs created is calculated from the total number of messages in the channel queue. In the case of immediate service jobs the calculation is based only on the message being entered into the queue at the time.
Finally, note that the
addrsperjob keyword is generally
only useful on channels that provide per-address service granularity.
Currently this is limited to PMDF-FAX channels. See Section 22.214.171.124 for
further information on using these keywords with PMDF-FAX.