4 research outputs found
Technical Report on Deploying a highly secured OpenStack Cloud Infrastructure using BradStack as a Case Study
Cloud computing has emerged as a popular paradigm and an attractive model for
providing a reliable distributed computing model.it is increasing attracting
huge attention both in academic research and industrial initiatives. Cloud
deployments are paramount for institution and organizations of all scales. The
availability of a flexible, free open source cloud platform designed with no
propriety software and the ability of its integration with legacy systems and
third-party applications are fundamental. Open stack is a free and opensource
software released under the terms of Apache license with a fragmented and
distributed architecture making it highly flexible. This project was initiated
and aimed at designing a secured cloud infrastructure called BradStack, which
is built on OpenStack in the Computing Laboratory at the University of
Bradford. In this report, we present and discuss the steps required in
deploying a secured BradStack Multi-node cloud infrastructure and conducting
Penetration testing on OpenStack Services to validate the effectiveness of the
security controls on the BradStack platform. This report serves as a practical
guideline, focusing on security and practical infrastructure related issues. It
also serves as a reference for institutions looking at the possibilities of
implementing a secured cloud solution.Comment: 38 pages, 19 figures
Fail Over Strategy for Fault Tolerance in Cloud Computing Environment
YesCloud fault tolerance is an important issue in cloud computing platforms and applications. In the event of an unexpected
system failure or malfunction, a robust fault-tolerant design may allow the cloud to continue functioning correctly
possibly at a reduced level instead of failing completely. To ensure high availability of critical cloud services, the
application execution and hardware performance, various fault tolerant techniques exist for building self-autonomous
cloud systems. In comparison to current approaches, this paper proposes a more robust and reliable architecture using
optimal checkpointing strategy to ensure high system availability and reduced system task service finish time. Using
pass rates and virtualised mechanisms, the proposed Smart Failover Strategy (SFS) scheme uses components such as
Cloud fault manager, Cloud controller, Cloud load balancer and a selection mechanism, providing fault tolerance via
redundancy, optimized selection and checkpointing. In our approach, the Cloud fault manager repairs faults generated
before the task time deadline is reached, blocking unrecoverable faulty nodes as well as their virtual nodes. This scheme
is also able to remove temporary software faults from recoverable faulty nodes, thereby making them available for future
request. We argue that the proposed SFS algorithm makes the system highly fault tolerant by considering forward and
backward recovery using diverse software tools. Compared to existing approaches, preliminary experiment of the SFS
algorithm indicate an increase in pass rates and a consequent decrease in failure rates, showing an overall good
performance in task allocations. We present these results using experimental validation tools with comparison to other
techniques, laying a foundation for a fully fault tolerant IaaS Cloud environment
Recovery for sporadic operations on cloud applications
Cloud-based systems get changed more frequently than traditional systems. These frequent changes involve sporadic operations such as installation and upgrade. Sporadic operations on cloud manipulate cloud resources and they are prone to unpredictable and inevitable failures largely due to cloud uncertainty. To recover from failures in sporadic operations on cloud, we need cloud operational recovery strategies. Existing operational recovery methods on cloud have several drawbacks, such as poor generalizability of the exception handling mechanism and the coarse-grained recovery manner of rollback mechanisms. Hence, this thesis proposes a novel and innovative recovery approach, called POD-Recovery, for sporadic operations on cloud. One novelty of POD-Recovery is that it is based on eight cloud operational recovery requirements formulated by us (e.g. recovery time objective satisfaction and recovery generalizability). Another novelty of POD-Recovery is that it is non-intrusive and does not modify the code which implements the sporadic operation. POD-Recovery works in the following innovative way: it first treats a sporadic operation as a process which provides the workflow of the operation and the contextual information for each operational step. Then, it identifies the recovery points (where failure detection and recovery should be performed) inside the sporadic operation, determines the unified resource space (the resource types required and manipulated by the sporadic operation), and generates the expected resource state templates (the abstraction level of resource states) for all operational steps. For a given recovery point inside the sporadic operation, POD-Recovery first filters the applicable recovery patterns from the eight recovery patterns it supports and then automatically generates the recovery actions for the applicable recovery patterns. Next, it evaluates the generated applicable recovery actions based on the metrics of Recovery Time, Recovery Cost and Recovery Impact. This quantitative evaluation leads to the selection of an acceptable recovery action for execution for a given recovery point. We implement POD-Recovery and evaluate it by recovering from faults injected into five representative types of sporadic operations on cloud. The experimental results show that POD-Recovery is able to perform operational recovery while satisfying all the recovery requirements and it improves on the existing recovery methods for cloud operations