MIBs

Property and Oid objects are used greatly in ``MIBs'', or Management Information Blocks. These are just very large property trees, and two important ones are the hosting MIB and the management MIB.

The hosting MIB is used by the hosting service to store all its information about the netlets it hosts: their resource usage, their machines' physical location, main class, and so on. Additionally a netlet has work space within the hosting MIB and has selective access to other parts.

The hosting MIB is not available to most netlets. They use the simple IHostingFacet which allows them to bind resources but not access the hosting MIB. (All this is invisible to Beatrix applications.) However, manager netlets get to use the IHostingControlFacet, as granted by the hosting service's administrator. IHostingControlFacet actually extends ITypedDataView, described below. However, we should stress again that this is entirely internal to Beatrix, so you shouldn't be seeking to gain access to it unless you're an advanced Beatrix developer.

The management MIB is a similar affair, and is a memory-only store shared between Beatrix managers. Only the current leader can write properties to the management MIB, and these are propagated to the other managers, so the data does survive a manager dying. The underlying mechanism is a property store, so changing a PropertySet is atomic.

To see an example use of the management MIB, properties, views and more go to Section  and look at the sample Webtrix code.