Yes / Fault tolerance is the ability of a system to respond swiftly to an unexpected failure. Failures in a cloud computing environment are normal rather than exceptional, but fault detection and system recovery in a real time cloud system is a crucial issue. To deal with this problem and to minimize the risk of failure, an optimal fault tolerance mechanism was introduced where fault tolerance was achieved using the combination of the Cloud Master, Compute nodes, Cloud load balancer, Selection mechanism and Cloud Fault handler. In this paper, we proposed an optimized fault tolerance approach where a model is designed to tolerate faults based on the reliability of each compute node (virtual machine) and can be replaced if the performance is not optimal. Preliminary test of our algorithm indicates that the rate of increase in pass rate exceeds the decrease in failure rate and it also considers forward and backward recovery using diverse software tools. Our results obtained are demonstrated through experimental validation thereby laying a foundation for a fully fault tolerant IaaS Cloud environment, which suggests a good performance of our model compared to current existing approaches. / Petroleum Technology Development Fund (PTDF)

Software development is an area in which companies not only need to keep up with the latest technology, but they additionally need to continuously increase their productivity to stay competitive in the industry. One company currently facing these challenges is Storytel - one of the strongest players on the Swedish audiobook market - with about a fourth of all employees involved with software development, and a rapidly growing workforce. With the purpose of understanding how the Storytel Tech Department is performing, this thesis maps Storytel’s productivity defined through the Four Key Metrics - Deployment Frequency, Delivery Lead Time, Mean Time To Restore and Change Fail Rate. A classification is made into which performance category (Low, Medium, High, Elite) the Storytel Tech Department belongs to through a deep-dive into the raw system data existing at Storytel, mainly focusing on the case management system Jira. A survey of the Tech Department was conducted, to give insights into the connection between human and technical factors influencing productivity (categorized into Culture, Environment, and Process) and estimated productivity. Along with these data collections, interviews with Storytel employees were performed to gather further knowledge about the Tech Department, and to understand potential bottlenecks and obstacles. All Four Key Metrics could be determined based on raw system data, except the metric Mean Time To Restore which was complemented by survey estimates. The generalized findings of the Four Key Metrics conclude that Storytel can be minimally classified as a ‘medium’ performer. The factors, validated through factor analysis, found to have an impact on the Four Key Metrics were Generative Culture, Efficiency (Automation and Shared Responsibility) and Number of Projects. Lastly, the major bottlenecks found were related to Architecture, Automation, Time Fragmentation and Communication. The thesis contributes with interesting findings from an expanding, middle-sized, healthy company in the audiobook streaming industry - but the results can be beneficial for other software development companies to learn from as well. Performing a similar study with a greater sample size, and additionally enabling comparisons between teams, is suggested for future research.

Wireless technology has increased in popularity since its invention, being embedded in many devices, such as smartphones, laptops, earphones etcetera. One of those technologies is Bluetooth, which is a short-range technology that is widely used worldwide. While being a popular and important technology, it is not as optimized as it could be, especially the standard Bluetooth 4.2. According to (Bluetooth, 2023)Bluetooth version 5 has four times the range of Bluetooth version 4.2 which is one area of improvement in Bluetooth. While limited Forward Error Correction (FEC)functionality in terms of (15,10) Hamming codes is present in the Bluetooth classic4.2 stack, however, it is not utilized in that version of Bluetooth. This thesis aims to implement a functionality in Bluetooth that uses FEC to increase the range. Before the experiments were conducted, multiple measurements were done in order to check if the hardware, such as the Bluetooth modules, antennas, air sniffer, could provide reliable and valid data. The experiments were conducted by streaming an audio sample of 48 kHz via Bluetooth and increasing the range until a certain percentage of fail rate in data transmission has occurred. FEC was then enabled, and the same experiment was repeated. The results from the experiments show that the range can be increased up to a few meters. Not only that, but the transmission without FEC allows a high level of errors without a connection cut-off. With FEC, the connection does not allow high levels of errors which means that the audio quality would not drop as low as it would have without FEC which means that a certain audio quality is preserved. This also makes the case for the implementation of higher modes of FEC into the Bluetooth stack to potentially increase the range of Bluetooth classic multiple times, but that implementation is beyond the scope of this thesis.