| dc.description.abstract | The Data Distribution Service (DDS) offers various Quality of Service (QoS) policies to manage the performance of DDS-based systems. The message delivery reliability and throughput are two essential performance factors for DDS-based systems, and thus, developers require tools to check the system configuration, monitor system performance, and determine the optimal sending rate for publishers in order to improve message delivery reliability and throughput. Unfortunately, existing tools do not efficiently support the verification of various DDS system configurations and their performance. Furthermore, current research on enhancing message delivery and throughput for DDS-based systems is still in its early stages. This is due to a lack of consideration for the one-to-many nature of DDS and the inability to quickly optimize performance without going through a trial-and-error process, which significantly limits its usability. To address these challenges, this dissertation proposes two approaches: (1) an emulation system to quickly evaluate and validate DDS-based system configurations during the design phase, and (2) an algorithm to adjust the publisher′s sending rates to improve message delivery reliability while optimizing throughput. Firstly, we developed an emulation system for a DDS-based system, called the Industrial Internet of Things (IIoT) Testbed, to enable system developers to quickly evaluate and verify system configurations before implementation. The IIoT Testbed facilitates the creation of system configurations and provides emulation results in a short time. Additionally, it allows users to analyze the results and fine-tune the QoS policies for improved performance. Secondly, we created an algorithm to adjust the publisher′s sending rates, aiming to enhance message delivery reliability and throughput in DDS-based systems. The algorithm calculates suitable sending rates based on observed performance values and assigns these rates to the publishers. Across different reliability scenarios (70–99.99% reliability), the proposed algorithm effectively improves performance, achieving system communication reliability of 99–99.99%. Notably, adjusting the publisher′s sending rate also increases per-topic throughput while enhancing per-topic reliability. | en_US |