This paper introduces a novel approach to automating failure diagnostics in distributed systems by combining fault injection and data analytics. We use fault injection to populate the database of failures for a target distributed system. When a failure is reported from production environment, the database is queried to find “matched” failures generated by fault injections. Relying on the assumption that similar faults generate similar failures, we use information from the matched failures as hints to locate the actual root cause of the reported failures. In order to implement this approach, we introduce techniques for (i) reconstructing end-to-end execution flows of distributed software components, (ii) computing the similarity of the reconstructed flows, and (iii) performing precise fault injection at pre-specified executing points in distributed systems. We have evaluated our approach using an OpenStack cloud platform, a popular cloud infrastructure management system. Our experimental results showed that this approach is effective in determining the root causes, e.g., fault types and affected components, for 71-100 percent of tested failures. Furthermore, it can provide fault locations close to actual ones and can easily be used to find and fix actual root causes. We have also validated this technique by localizing real bugs that occurred in OpenStack.

5G and beyond (B5G) applications generate tremendous computing-intensive, latency-sensitive, and privacy-sensitive tasks, which differ from the legacy cloud computing tasks, requiring more sophisticated scheduling strategies. We must satisfy the stringent service requirements, particularly privacy preservation that has not been sufficiently considered in the past. Meanwhile, we need to balance the tasks offloaded to different edge nodes to avoid overwhelming some fog nodes, which may degrade the overall performance. To appropriately schedule the privacy-sensitive tasks while balancing the traffic load, we define IoT tasks according to their security need, processing time, and real-time requirement and segment IoT tasks into smaller pieces based on their privacy levels. The sliced tasks are scheduled to multiple fog nodes with satisfactory security reputations to avoid a compromised fog node handling a whole task. Meanwhile, we consider the constraint of the response time of all available fog nodes before scheduling IoT tasks to avoid chaos task scheduling that may overwhelm some fog nodes. Regarding this, we propose a reinforcement learning (RL) model in which the agent tends to satisfy the required latency and security requirements while avoiding overloading some fog nodes to minimize the average delay. The numerical results demonstrate that the proposed approach performs well in a better-balanced load and less performance violation in latency and security.

Numerous new applications have been proliferated with the mature of 5G, which generates a large number of latency-sensitive and computationally intensive mobile data requests. The real-time requirement of these mobile data has been accommodated well by fog computing in the past few years, mainly through offloading tasks to fog nodes in the vicinity. On the other hand, the user-privacy hidden in the Internet-of-Things (IoT) data has not been sufficiently considered in the presence of insecure fog nodes. It is risky to offload an entire mission-critical task to just one fog node or several fog nodes owned by the same service provider (SP), especially when the SP is marked with low-security credit and tends to collect data information of users for malicious use. To address this issue, we classify IoT user tasks based on their security requirements, divide them into different numbers of smaller fragments, and, finally, offload the segments of a task to multiple fog nodes owned by the same or various SPs according to their security requirements. The selected fog nodes will collaboratively serve the divided fragments to avoid the possible damage caused by the leak of sensitive data due to compromised fog nodes of malicious SPs. For this, we propose an integer linear programming (ILP) model and a dynamic programming algorithm to maximize the number of successfully served IoT data tasks with satisfactory security requirements while minimizing the end-to-end transmission delay. The numerical results show that the proposed ILP model and algorithm can significantly increase the successful provisioning ratio for tasks with high-security requirements.

The incoming 5G technology is expected to proliferate tremendous internet-of-thing (IoT) services with real-time and mobility requirements, which are quite different from the legacy cloud services. Due to the centralized management relying on distant datacenters, cloud computing is short of satisfying the stringent IoT requirements, such as ultra-low latency, mobility, etc. Instead, distributed edge computing, such as fog computing has been coined as a promising approach and has received enormous attention in recent years. In this paper, to optimally provision the huge volume of IoT services with significant diversity, we propose to efficiently organize the leisure network devices in the network edge to form fog networks (fogs), which are then integrated with the cloud to provide storage and computing resources. Specifically, we propose two Integer Linear Programming (ILP) models to solve the fog planning issue under the integrated Cloud-Fog (iCloudFog) framework. In the first ILP model, the objective is to minimize the CAPEX cost caused by planning fogs and the OPEX cost caused by utilizing the planned fogs. In the second ILP model, the objective is to minimize the power consumption while maximizing the number of successfully provisioned IoT tasks on the planned fogs. The proposed ILP models are numerically evaluated by considering different IoT task requirements, such as real-time and mobility. The numerical results show that efficiently planned fogs can help to reduce the planning overhead while satisfying diverse IoT task requirements.

The Linux community has witnessed the rapid development of eBPF technology that allows users to load custom programs into the Linux kernel to extend its capabilities. A key feature that makes eBPF powerful is eBPF maps, which provide data storage and communication capabilities for eBPF programs. However, despite being widely used in eBPF programs, the performance of eBPF maps has received little attention. To understand the performance characteristics of eBPF maps, we conduct a comprehensive benchmark on them. The benchmark results demonstrate the access overhead of different types of eBPF maps and reveal the impact of various factors on the access overhead. By analyzing the benchmark results, we derive some implications for eBPF users to use eBPF maps more efficiently.