PMDF System Manager's Guide

When immediate delivery jobs are used they normally process only a subset of the messages queued for the channel. There may be other messages that were queued to the channel at some prior time that will not be processed. However, on some channels, particularly those that only provide a link to a single remote system, this sort of operation may be inappropriate: if the immediate delivery job is successful in connecting to the remote system it may be able to easily process all the messages that are queued.

The serviceall and noserviceall keywords control this behavior. noserviceall, the default, indicates that immediate delivery jobs should only process the messages they were queued to process. serviceall specifies that immediate jobs should attempt to process all messages queued to the channel.

It may be tempting to indulge in use of serviceall on most or all channels. Be warned, however, that use of serviceall is probably not suitable for most channels that connect to multiple remote systems, or channels that entail lots of per-message overhead. If serviceall is used on such channels it may cause a dramatic increase in network and message processing overhead and the net result may be slower message processing overall.

Note that these keywords do not change the order in which message processing occurs. Immediate jobs always attempt to process the messages they were created to process prior to turning to other messages that are also in the channel queue.