Logging Messages

Currently we are in the process of adopting EDRA in our software development process. In this process we are trying to map our own architectural requirements to EDRA functionality. For some of our requirements this means creating new EDRA handlers, or even creating new services (like the directory service described earlier). Today another requirement came up…

‘Within our systems it must be possible to monitor the complete flow of a message and all messages that are send as a result of this message’

… In our architecture we recognize 3 different kind of services: user interface services, business process services and business information services. These kind of services will be build as separate services according to the ‘EDRA specs’. So a user interface service (for example an ASP.NET page) is using the EDRA infrastructure to communicate with a business process service. This business process service is using the EDRA infrastructure to communicate with an business information service. All services in this example are completely separated from each other. This is a bit different from the Global Bank example (in my opinion) in which for example the process is implemented in a page controller in the front- end. In the Global Bank situation there is only 1 EDRA call to a service action (from user interface all the way to the business action). In our preferred way, there will be a least two EDRA calls, one from to the user interface to the business process service AND one from the business process service to the business information service.

Our logging requirement means that we would like to ‘see’ that the request message send from the user interface to the business process service “belongs” to the request message that is send from the business process service to the business information service.

At this moment I haven’t found the best solution for this requirement. These are my thoughts at the moment:

• Implement a new logging handler that simply logs the message in a database. I think we can use the logging handler of Global Bank as a starting point for this
• Define a set of default fields that are available on EVERY message that is send in the architecture. I am thinking of ‘timestamp’ and some sort of an ‘request id’
• If a message is send from the user interface service to the business process service, supply an ‘request id’ in the message. (this message is logged in the database by the log handler). In the business process service use the ‘request id’ in the message from the user interface to store in the ‘request id’ field of the message that is send to the business information service (also this message is logged in the database by the log handler)
• Now there is a way to ‘link’ (using the ‘request id’) the two log entries in the database to each other.
• Make some sort of overview that shows the relation between the different messages. Now it is possible to see that a call to service ‘A’ means that also messages are sent to service ‘B’ and ‘C’

Any better ideas? .... let me know!