Runtime Monitoring - Design Patterns

On the basis of a Publish/Subscribe mechanism, the Runtime Monitoring component has to receive from the Host Monitoring components information on the status of the hosts where the application is deployed. The Runtime Monitoring component processes the information obtained in order to evaluate if the SLA is satisfied. In the negative case, the Runtime Monitoring component notifies a violation and asks for recovery action. It can also act proactively, and intercept before the violation, in this case considering thresholds for violation threats. A generic application monitor could make use of the Bridge pattern in order to break dependencies between host monitor and the concrete application monitor, so that these can vary independently.

This pattern is appropriate in all situations where the client needs to know what is the current status of the agreed SLA, to be aware of the work progression. The user wants to know if the SLA has been violated to be able to claim compensation, but also to reschedule the job. The user will also want to be alerted of imminent violation, called threats. This pattern is needed for accounting.