Managing Ensemble Productions - InterSystems Documentation

Working with Configuration Items
a response to the outside entity’s original request. Some requests do not require a response; if this is the case, none is
returned.
• Business process class — Instances of the Ens.BusinessProcess class accept requests from host classes inside
Ensemble — business services or business processes — and either process the requests or relay them to other host
classes inside Ensemble for processing. A business process class corresponds to a single, well-defined business task
that needs to be performed. The business process generates whatever activity is needed to complete this task. It invokes
various lower-level host classes — business processes or business operations — and it controls the logic of these
invocations. When all of its internal processing is complete, a business process formulates and returns a response to
the original request, if a response is needed. Some requests do not require a response; if this is the case, none is returned.
• Business operation class — Instances of the Ens.BusinessOperation class accept requests from host classes inside
Ensemble — business services or business processes — and either process the requests or relay them to entities outside
Ensemble for processing. A business operation class consists of one or more methods, each of which corresponds to
a single, well-defined external or internal operation that needs to be performed, such as retrieving a specific piece of
data or making a specific type of calculation. When its internal processing is complete, a business process formulates
and returns a response to the original request, if a response is needed. Some requests do not require a response; if this
is the case, none is returned. By convention, a business operation is an extremely specific operation that contain very
little logic and does what is requested of it without calling further operations or branching in any way. When the design
of the production demands logic, this is contained in a higher-level business processes.
A host class must be compiled and loaded before the corresponding business host — business service, business process,
or business operation — can be added to the production. Once the business host is added to the production, it has configurable
settings that can be adjusted using the display on the Ensemble Management Portal [Ensemble] > [Productions] > [Configuration]
page.
A host class determines how a configuration item can be configured, by publishing its configurable properties in a class
parameter called SETTINGS. Any property listed in the SETTINGS parameter for a host class automatically appears in the
display on the [Ensemble] > [Productions] > [Configuration] page, whenever an item of that host class is selected for configuration.
You can edit and save values on the [Ensemble] > [Productions] > [Configuration] page without editing or recompiling
the host class itself. Any changes you make are applied immediately, without requiring you to stop and restart a running
production. The same is true of production-wide properties defined in the production class and exposed for configuration
by using the SETTINGS class parameter in the production class.
A host class is sometimes called a business class. Either term is appropriate.
3.3 Working with Configuration Items
An Ensemble configuration item is any business service, business process, or business operation within an Ensemble production.
Every configuration item extends the class Ens.Item, and consists of a name, a reference to a specific host class,
and a group of operational settings that determine how the host class behaves when it is a member of a running production.
There is a clear difference between Ensemble configuration items and Ensemble host classes:
• An host class is executable source code.
• An configuration item is a specialized configuration of a host class.
A configuration item is always associated with a specific production. It may resemble or duplicate items in other productions.
Each production is an entirely closed universe that does not use configuration items from other productions.
An Ensemble production contains the following types of configuration item:
• Business services (includes business metrics)
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