The Settings Hierarchy

The SIF Agent is designed with scalability in mind. Depending on the architecture and capabilities of the application, it can be deployed in a single school or installed centrally to serve an entire district or service agency. Consequently, it's important that the administrator have the flexibility to fine-tune how the agent interacts with each SIF Zone to which it connects. For example, in a school district, elementary school zones may need to work slightly differently than secondary school zones. In a hosted service agency or state deployment, the agent may connect to the zones of many member districts, each of which will have their own unique requirements.

To promote a high level of customization, the agent's settings are arranged in a hierarchy where settings at one level in the tree are inherited from parent levels:

• Global Agent Settings
  
  

  • Zone Group Settings
    
    

    • Zone Settings

In other words, Zone Group Settings inherit from the Global Agent Settings, and Zone Settings inherit from the parent Zone Group. Since Zone Groups are an optional feature (a zone can exist outside of a group), zones always inherit their settings from the immediate parent, which in many cases is the global Agent defaults.

Let's look at an example. Assume that a school district has a central zone integration server, with multiple school zones representing each individual school. All agents in the district connect to this one server on the local network. The Messaging Mode setting determines whether the agent will use Push or Pull mode to retrieve its messages from the server. The default is usually set to Push in the Global Agent Settings, because that mode is much more efficient than Pull. Thus, by default the agent will use Push mode when it connect to each of the school zones.

Opening the Zone Settings dialog box reveals the zone is inheriting defaults (the Use Defaults checkbox is marked):

Figure 4. Inherited setting for a zone
Suppose, however, that a state department of education offers a particular service on a state zone, which is managed by a second zone integration server located at the state. For this one zone, you wish to use Pull mode to retrieve messages over the public internet. Push mode cannot be used in this case because of firewall and networking issues (i.e. the state's ZIS cannot "see" the agent at the district in order to push messages to it, so the agent must instead pull its messages from the server).

You can override the Messaging Mode setting for this one zone by changing it in the Zone Settings dialog box. The Use Defaults checkbox is cleared and the messaging mode changes to Pull mode:

Figure 5. Overridden setting for a zone
Now the Agent will use Pull mode for this one state zone, but Push mode for all other zones.