Resource Sharing for Multi-Tenant Nosql Data Store in Cloud

Thesis (Ph.D.) - Indiana University, Informatics and Computing, 2015Multi-tenancy hosting of users in cloud NoSQL data stores is favored by cloud providers because it enables resource sharing at low operating cost. Multi-tenancy takes several forms depending on whether the back-end file system is a local file system (LFS) or a parallel file system (PFS), and on whether tenants are independent or share data across tenants In this thesis I focus on and propose solutions to two cases: independent data-local file system, and shared data-parallel file system. In the independent data-local file system case, resource contention occurs under certain conditions in Cassandra and HBase, two state-of-the-art NoSQL stores, causing performance degradation for one tenant by another. We investigate the interference and propose two approaches. The first provides a scheduling scheme that can approximate resource consumption, adapt to workload dynamics and work in a distributed fashion. The second introduces a workload-aware resource reservation approach to prevent interference. The approach relies on a performance model obtained offline and plans the reservation according to different workload resource demands. Results show the approaches together can prevent interference and adapt to dynamic workloads under multi-tenancy. In the shared data-parallel file system case, it has been shown that running a distributed NoSQL store over PFS for shared data across tenants is not cost effective. Overheads are introduced due to the unawareness of the NoSQL store of PFS. This dissertation targets the key-value store (KVS), a specific form of NoSQL stores, and proposes a lightweight KVS over a parallel file system to improve efficiency. The solution is built on an embedded KVS for high performance but uses novel data structures to support concurrent writes, giving capability that embedded KVSs are not designed for. Results show the proposed system outperforms Cassandra and Voldemort in several different workloads

Priority-Driven Differentiated Performance for NoSQL Database-As-a-Service

Designing data stores for native Cloud Computing services brings a number of challenges, especially if the Cloud Provider wants to offer database services capable of controlling the response time for specific customers. These requests may come from heterogeneous data-driven applications with conflicting responsiveness requirements. For instance, a batch processing workload does not require the same level of responsiveness as a time-sensitive one. Their coexistence may interfere with the responsiveness of the time-sensitive workload, such as online video gaming, virtual reality, and cloud-based machine learning. This paper presents a modification to the popular MongoDB NoSQL database to enable differentiated per-user/request performance on a priority basis by leveraging CPU scheduling and synchronization mechanisms available within the Operating System. This is achieved with minimally invasive changes to the source code and without affecting the performance and behavior of the database when the new feature is not in use. The proposed extension has been integrated with the access-control model of MongoDB for secure and controlled access to the new capability. Extensive experimentation with realistic workloads demonstrates how the proposed solution is able to reduce the response times for high-priority users/requests, with respect to lower-priority ones, in scenarios with mixed-priority clients accessing the data store

Foundations and Technological Landscape of Cloud Computing

The cloud computing paradigm has brought the benefits of utility computing to a global scale. It has gained paramount attention in recent years. Companies are seriously considering to adopt this new paradigm and expecting to receive significant benefits. In fact, the concept of cloud computing is not a revolution in terms of technology; it has been established based on the solid ground of virtualization, distributed system, and web services. To comprehend cloud computing, its foundations and technological landscape need to be adequately understood. This paper provides a comprehensive review on the building blocks of cloud computing and relevant technological aspects. It focuses on four key areas including architecture, virtualization, data management, and security issues

Designing a Modern Software Engineering Training Program with Cloud Computing

The software engineering industry is trending towards cloud computing. For our project, we assessed the various tools and practices used in modern software development. The main goals of this project were to create a reference model for developing cloud-based applications, to program a functional cloud-based prototype, and to develop an accompanying training manual. These materials will be incorporated into the software engineering courses at WPI, namely CS 3733 and CS 509

Taming the Cloud Object Storage with MOS

Abstract Cloud object stores today are deployed using a single set of configuration parameters for all different types of applications. This homogeneous setup results in all applications experiencing the same service level (e.g., data transfer throughput, etc.). However, the vast variety of applications expose extremely different latency and throughput requirements. To this end, we propose MOS, a Micro Object Storage architecture with independently configured microstores each tuned dynamically for a particular type of workload. We then expose these microstores to the tenant who can then choose to place their data in the appropriate microstore according the latency and throughput requirements of their workloads. Our evaluation shows that compared with default setup, MOS can improve the performance up to 200% for small objects and 28% for large objects while providing opportunity of tradeoff between two

Cloud Forensic: Issues, Challenges and Solution Models

Cloud computing is a web-based utility model that is becoming popular every day with the emergence of 4th Industrial Revolution, therefore, cybercrimes that affect web-based systems are also relevant to cloud computing. In order to conduct a forensic investigation into a cyber-attack, it is necessary to identify and locate the source of the attack as soon as possible. Although significant study has been done in this domain on obstacles and its solutions, research on approaches and strategies is still in its development stage. There are barriers at every stage of cloud forensics, therefore, before we can come up with a comprehensive way to deal with these problems, we must first comprehend the cloud technology and its forensics environment. Although there are articles that are linked to cloud forensics, there is not yet a paper that accumulated the contemporary concerns and solutions related to cloud forensic. Throughout this chapter, we have looked at the cloud environment, as well as the threats and attacks that it may be subjected to. We have also looked at the approaches that cloud forensics may take, as well as the various frameworks and the practical challenges and limitations they may face when dealing with cloud forensic investigations.Comment: 23 pages; 6 figures; 4 tables. Book chapter of the book titled "A Practical Guide on Security and Privacy in Cyber Physical Systems Foundations, Applications and Limitations", World Scientific Series in Digital Forensics and Cybersecurit