SingleThreadDelivery
Set single-threaded delivery V8.8 and later
Ordinarily, when sendmail
processes the queue, it pays relatively little
attention to other sendmail
processes that might be processing the same queue at
the same time. It locks a single qf
file during delivery
so that no other sendmail will
attempt delivery of that message at the same time,
but that is all. When sending many messages to a
single other host, it is possible for multiple,
parallel sendmail processes to
try to deliver different messages from that queue to
that single host all at once.
When parallelism is not desirable, you might wish to
set up sendmail to be
single-threaded. This ensures that only a single
sendmail will ever be
delivering to a given host at a given time.
Single-threaded delivery is enabled with the
SingleThreadDelivery
option, the forms
of which are as follows:
O SingleThreadDelivery=bool ← configuration file (V8.8 and later) -OSingleThreadDelivery=bool ← command line (V8.8 and later) define(`confSINGLE_THREAD_DELIVERY',`bool') ← mc configuration (V8.8 and later)
The argument bool
is of
type Boolean. If it is missing,
the default value is true (deliver single-threaded).
If the entire SingleThreadDelivery
option is missing,
the default becomes false (deliver in parallel). The
default for the mc
configuration technique is false.
Note that the SingleThreadDelivery
option will work
only if the HostStatusDirectory
option is also
declared (HostStatusDirectory on
page 1037). If it is not,
sendmail ...
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