Below please find draft 1 (fred's version :-) of text for describing
the concerns expressed by "Issue 3". I have taken the liberty of
expanding from just the aggregation perspective to include the opposite
case. This opposite case is one where things which end up at the same
place may be referring to separate external entities, as opposed to the
aggregation case where things addressed to the same place may be
directed to different instances of a service.
/fred
Issue 3: Responsibilities of Manageability Provider: Information
Aggregation or Separation
The system providing manageability capabilities for a service must be
aware of configuration of the service from the caller's point of view.
This configuration may be dependent upon external hardware or
software options. Manageability may need to be implemented differently
depending upon the requests made with respect to the caller's point of
view.
Consider two examples. The first case is that of a hardware routed
service. By this, we refer to the case where some hardware device
offers up a service at, for example,
http://external.example.com/theService. Upon receipt of messages for
that URL, the device forwards the messages to any service from the set
These services are identical, providing access to the same underlying
business resource.
If, say, a query regarding metrics were made regarding the service
http://external.example.com/theService, it is the responsibility of the
provider of manageability to aggregate the results from the three
underlying services to provide a meaningful response.
A second example is one wherein a single service is known by two
distinct names. In this case, consider the service at
http://services.example.com/creditCheck. External to the Example
Company, this service is known as
"http://ourservices.example.com/creditCheck", while internally, this
service is known as "http://extservices.example.com/creditCheck".
However, in both cases, the underlying service is performed by the same
machine, service, etc. The service itself is aware of the
means by which it is addressed, and it adjusts itself appropriately.
In this case, the provider of manageability must be similarly aware.
Queries regarding the two URL's must be accounted for separately, even
though the underlying service is identical, quite possibly with the
distinction between the two maintained only using different name
servers.
--
Fred Carter / AmberPoint, Inc.
mailto:fred.carter@amberpoint.com
tel:+1.510.433.6525 fax:+1.510.663.6301
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