Pathmaker Programming Guide

Designing a Pathmaker Application
Preparing for Pathmaker Application Development
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class name, allowing the application requester to issue a legal Pathway SEND
statement.
Although you can designate which custom services should be packaged into which
custom servers and what the active server class for each service should be in the
application design specification, these decisions can be quickly changed during
testing. The Pathmaker product can easily be used to repackage services into servers,
change the active server class for a service, and regenerate the mapping requester
numerous times.
See Section 7 for details about servers and server classes and a description of service to
server class mapping.
Grouping Services
For most applications, the two primary design goals for servers and server classes are
to conserve system data space and to achieve consistent performance from the
application. These two goals can be met by first grouping services by files used (file
set), then grouping services by service time.
Grouping services by file sets conserves system data space. This approach is effective
because it reduces the number of times a given file is opened and the number of
processes that can open it. Grouping services by file sets is especially important for
very large applications with many processes that open files.
Grouping services by service time helps an application achieve consistent
performance. This approach is effective because servers complete each service before
continuing to the next. Requests for services in a server class are put in a queue until
they can be processed. If any one service takes longer than the average, the shorter
services will occasionally have a long response time. Grouping services by service
time keeps short transactions short. In a production environment, a system manager
could easily change the mapping requester to solve performance problems. For
example, the system manager could change the active server class for a service or add
new server classes to isolate services with long or erratic response times.
To use this approach for grouping Pathmaker custom services, follow these steps:
1. Group services by file sets.
You can do this by grouping together services that address the needs of a
particular area of the business. For example, group services that perform
functions for the accounting department. When you group services that perform
related functions, you also group services that use the same set of files.
You do not have to strictly adhere to this grouping; as long as the majority of files
used by a server are accessed by the majority of services, your grouping should be
adequate.