Scenario Model Based Aproaches For The Testing Of DDS Component-Based Distributed Systems

With the wide application of Internet technology,more and more application systems use dynamic open network environment as the platform for computing and operation and their functional requirements are increasingly complicated.DDS component-based distributed system has been widely used in many fields,due to its strong real-time,openness,scalability and loose coupling characteristics,such as civil industrial systems,vessel equipment,etc.For example,DDS middleware is used to build a naval mission-critical system for integrated hardware and software integration.These DDS-based mission-critical systems have high quality requirements,but they also have different characteristics from the general software systems in terms of R&D mode,system structure,application requirements,and new failure scenarios,which have brought new challenges to the research of test methods and techniques,including test case generation.Aiming at test case generation for DDS component-based distributed system testing,this thesis proposes a scenario modeling approach for DDS component-based distributed system,which models scenarios with risk of failure in the system under testing.At the same time,a test case generation method based on scenario model is also proposed.By test data sequence generation and fault injection on the event,a test case set easier for finding system defects can be constructed.The main contributions of the work are as follows:(1)A scenario modeling method based on extended regular expression is proposed.The extended regular expression is used to construct an event sequence pattern for the scenarios with risk of failure in the system under test to express the sequence of the interactions in scenarios.Then,the event data in the sequence is modeled to describe the value constraints among events,and fault injection requirements are added to the scenario model to improve the effectiveness in discovering system failures.(2)A test case generation approach based on scenario model is proposed.A test event sequence corresponding to the scenario is automatically generated according to the event sequence pattern in the scenario model,and then the test data is filled for events in the sequence according to the event data pattern.In the generation,online supplement and verification of the test data is also supported.(3)A test execution framework based on DDS middleware is proposed.By designing a mechanism that can dynamically construct DDS message receiving and dispatching programs,the event data sequence in the test case can be executed.Then the test execution information is collected to get test result for evaluating the effects of the test case.(4)Based on the approach proposed in this thesis,a prototype system for testing DDS component-based distributed system is implemented.It is applied to naval mission system testing practice to verify the effectiveness of the proposed approach.