Moritz Balz

SyLaGen: an extendable tool environment for generating load

Measuring run time behaviour of systems under load can cause the need for complex workload definitions, measurement strategies and integration of load generation techniques. In this contribution we present SyLaGen (“Synthetic Load Generator”), a load generation environment that focuses on extendability with respect to four different aspects: First, a system under test may offer different interfaces for handling external requests, thus a load generator must be able to handle different protocols randomly and in parallel. Second, load generation for a client-server system may require complex client behaviour that cannot be formulated in a simple descriptive way, but instead with non-trivial algorithms that have to be implemented programmatically. Third, more than simple atomic measurements may be required in complex environments, so that strategies applying sequences of measurements to a system should be configured. Finally, comprehensive requirements engineering may result in complex use cases that cannot be modelled as linear scripts.

Embedding process models in object-oriented program code

Process modeling has usually a strong connection with run time platforms that allow dynamic configuration and adjustment. While this is reasonable for the operation of large applications, it is of no help in cases when program code is to be engineered, documented or verified with respect to process models. We propose a design pattern for process models that allows to embed complete model semantics in object-oriented program code fragments. The program code can thus be validated and executed with respect to process model semantics and design tools.

Tool support for continuous maintenance of state machine models in program code

Software under development is considered by developers at different levels of abstraction, often with formal model specifications that describe actual program code. However, there are semantic barriers between high-level specifications and the resulting programs. In this contribution we introduce a set of tools that maintain multiple abstraction levels in appropriate program code patterns throughout the development process, including run time and monitoring. This makes the program code the only notation necessary for expressing different abstraction levels and improves maintenance of high-level specifications, synchronization of different specifications, and design recovery.