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Cloud computing is broadly recognized as one of major factors in achieving more flexible, scalable, and efficient systems. However, as customers lose the direct control of their data and applications hosted by cloud providers, the trustworthiness of cloud services is a main issue that hinders the deployment of cloud applications. In this paper, we have developed a novel framework to detect compromises...
SSL VPN system depends on TUN device on Linux host. Without TUN device, it can't be deployed on Linux hosts. In order to overcome this limitation, a new kind of SSL VPN system is developed. This system is based on simulated virtual NIC based on loopback interface. With the help of simulated virtual NIC, SSL VPN client can be deployed on Linux hosts without TUN devices. Thus a Linux host without TUN...
Many recent data intensive parallel systems builds with cost effective hardware and combine compute and storage facilities. Since bandwidth-bisecting networks are the norm, distributing jobs near data provides significant performance improvements. However, the data locality information is not easily available to the programmer. It requires interaction with file system internals, or the adoption of...
The smallest instance offered by Amazon EC2 comes with 615MB memory and a 7.9GB disk image. While small by today's standards, embedded web servers with memory footprints well under 100kB, indicate that there is much to be saved. In this work we investigate how large VM-populations the open Stack hyper visor can be made to sustain, by tuning it for scalability and minimizing virtual machine images...
Although capacities of persistent storage devices evolved rapidly in the last years, the bandwidth between memory and persistent storage devices is still the bottleneck. As loosely coupled data sharing applications running in cluster environment may need an enormous number of files, the access to these files might become the bottleneck. With the quick development of the server and high-speed network,...
While there has been active development of the Linux kernel, little has been done to address kernel bugs with gradually increasing lifetimes. From our statistical analysis, the average lifetime of kernel bugs in each kernel development cycle has increased 2.87 times from the years between 2008 and 2012. This indicates the instability of Linux kernels. To reduce bug lifetime, we present a Kernel Instant...
Cloud networking imposes new requirements in terms of connection resiliency and throughput among virtual machines, hypervisors and users. A promising direction is to exploit multipath communications, yet existing protocols have a so limited scope that performance improvements are often unreachable. Generally, multipathing adds signaling overhead and in certain conditions may in fact decrease throughput...
This paper introduces method for implementing NFS protocol for larger block/network packets transfer over to NAS [Network Attached Storage] from Highly Available clients. NAS storage scalability is habitually inadequate to the volume of the appliance. Addition of an appliance is reasonably easy, but access to the pooled contents as a mono entity is not. In this approach, NAS supports file sharing...
We present CrowdCL, an open-source framework for the rapid development of volunteer computing and OpenCL applications on the web. Drawing inspiration from existing GPU libraries like PyCUDA, CrowdCL provides an abstraction layer for WebCL aimed at reducing boilerplate and improving code readability. CrowdCL also provides developers with a framework to easily run computations in the background of a...
In this paper we present our ongoing work on implementing the multi-resource server technology in the Linux operating system running on multi-core architectures. The multi-resource server is used to control the access to both CPU and memory bandwidth resources such that the execution of real-time tasks become predictable. We are targeting Legacy applications to be migrated from single to multi-core...
We present a high performance logging system for embedded UNIX and GNU/Linux applications. Compared to the standard UNIX and GNU/Linux logging method, syslog, our method has two orders of magnitude lower latency and an order of magnitude higher message throughput. This speed-up is mainly due to the use of a memory-mapped file as the means of inter-process communication, fewer memory copies and the...
In recent years, virtualization technology enables multiple virtual machines to run on a physical machine, where each virtual machine can run independently and own its operating system. Virtualization technology has been adopted in many IT industries because of its ability to improve hardware resource utilization, achieve low-power consumption, simplify server management, and reduce maintenance cost...
Currently, the virtualization technologies can integrate multiple operating systems into a high-performance server to maximize the utilization of the server's resources. This server can serves more users. However, the driver faults in virtual machine still seriously affect the reliability of the virtual machine, and even affect the reliability of the entire server. This paper presents Chariot, a high...
Virtualization is rapidly gaining acceptance as a fundamental building block in enterprise data centers and is the core component of cloud computing platforms. It is most known for improving efficiency and ease of management. While this technology is meant to enhance the security of computer systems, some recent attacks show that virtual machine technology has much vulnerability and becomes exposed...
Cluster based multiprocessor scheduling can be seen as a hybrid approach combining benefits of both partitioned and global scheduling. Virtual clustering further enhances it by providing dynamic cluster resource allocation and applying hierarchical scheduling techniques. Over the years, the study of virtual cluster scheduling has been limited to theoretical analysis. In this paper, we present our...
We demonstrate that a certain class of side-channel attacks is feasible due to unintentional cache contentions between code segments in cryptographic applications. These inadvertent contentions should be considered as a flaw in the implementation of cryptographic applications, which necessitates a software analysis framework to identify their primary cause and check the effectiveness of proposed countermeasures...
The growing number of applications that use the Session Initiation Protocol (SIP) to manage media sessions over IP is placing increasing demands on the SIP proxy servers (SPS) that make up the core of the SIP network. In this work we investigate the performance of OpenSIPS, an open source SPS. We have collected a large set of experimental data to characterize the performance of the SPS under various...
Software-implemented fault injection (SWIFI) is an established experimental technique to evaluate the robustness of software systems. While a large number of SWIFI frameworks exist, virtually all are based on a single-fault assumption, i.e., interactions of simultaneously occurring independent faults are not investigated. As software systems containing more than a single fault often are the norm than...
The domain name system (DNS) is an essential component of Internet. As it is expected to be used by all legitimate users and applications, generally there are less inspections, restrictions and filters on it. Botnets rely on this open component to accomplish their malicious operation. Therefore, to defeat the single point of failure and evade static blacklists and firewalls, they employ DNS-based...
Storage cloud systems achieve economies of scale by serving multiple tenants from a shared pool of servers and disks. This leads to the commingling of data from different tenants on the same devices. Typically, a request is processed by an application running with sufficient privileges to access any tenant's data; this application authenticates the user and authorizes the request prior to carrying...
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