Reliability.mediawiki

@@ -25,7 +25,7 @@ Fault tolerance —both hardware and software— is achieved through some kind o
 
 == Design decisions ==
 
-Reliability building block goal is to improve the reliability aspects of the universAAL platform. Therefore the reliability building block is a vertical layer cross over all layers of universAAL, especially in the Middleware. This can be done by dealing with to major challenges of reliability and enhance the system efficiency. The first action point, the creation of a framework to diagnose the system behaviour by detecting the faults that might occur during the systems operation, and take decisions to overcome such cases. Taking into consideration the existing components of the Middleware, the following components will be reused in the Diagnosis Framework: Context Events, Context Bus and the Situation Reasoner [http://forge.universaal.org/wiki/uaal_context:Home| (see Context Group wikipages for more details)]. The Diagnosis Framework, should not create further effort on the operational load of the platform or interrupt other services. The Middleware has a message based communication.Hence, fault detection mechanisms is also using message classification algorithms in order to categorize messages and differentiate all message types interacting in the platform. The diagnosis framework uses a knowledge base of rules that determine the behaviour of the system and define possible solutions. This knowledge base has to be fed continuously with new knowledge and cases to be able to decide in more and more use cases. A Fault injection framework has been implemented to create a high effort testing scenarios for a number of nodes in an AAL space, after the end of this check, a file of feedback results can be used in the knowledge base that is used in the Diagnosis Framework. The Fault Injection Framework in its final version will be fully independent bundle from the Middleware. This will also give universAAL administrators the ability to test the functionality of any uAAL space remotely. The third bundle in the Reliability building block is the Time Triggered patch, this patch is giving the users of universAAL platform the possibility to have an advantage of using a time triggered communication in there uAAL spaces where many reliability aspects are taken already into consideration in the infrastructure used in such communication (e.g. global time synchronization, reliable communication of critical events in the system).
+Reliability building block goal is to improve the reliability aspects of the universAAL platform. Therefore the reliability building block is a vertical layer cross over all layers of universAAL, especially in the Middleware. This can be done by dealing with to major challenges of reliability and enhance the system efficiency. The first action point, the creation of a framework to diagnose the system behaviour by detecting the faults that might occur during the systems operation, and take decisions to overcome such cases. Taking into consideration the existing components of the Middleware, the following components will be reused in the Diagnosis Framework: Context Events, Context Bus and the Situation Reasoner [https://github.com/universAAL/context/wiki| (see Context Group wikipages for more details)]. The Diagnosis Framework, should not create further effort on the operational load of the platform or interrupt other services. The Middleware has a message based communication.Hence, fault detection mechanisms is also using message classification algorithms in order to categorize messages and differentiate all message types interacting in the platform. The diagnosis framework uses a knowledge base of rules that determine the behaviour of the system and define possible solutions. This knowledge base has to be fed continuously with new knowledge and cases to be able to decide in more and more use cases. A Fault injection framework has been implemented to create a high effort testing scenarios for a number of nodes in an AAL space, after the end of this check, a file of feedback results can be used in the knowledge base that is used in the Diagnosis Framework. The Fault Injection Framework in its final version will be fully independent bundle from the Middleware. This will also give universAAL administrators the ability to test the functionality of any uAAL space remotely. The third bundle in the Reliability building block is the Time Triggered patch, this patch is giving the users of universAAL platform the possibility to have an advantage of using a time triggered communication in there uAAL spaces where many reliability aspects are taken already into consideration in the infrastructure used in such communication (e.g. global time synchronization, reliable communication of critical events in the system).
 
 == Requirements ==