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The amount of useful semi-structured data on the web continues to grow at a stunning pace. Often interesting web data are not in database systems but in HTML pages, XML pages, or text les. Data in these formats is not directly usable by standard SQL-like query processing engines that support sophisticated querying and reporting beyond keyword-based(More)
Internet security incidents have shown that while network cryptography tools like SSL are valuable to Internet service, the hard problem is to protect the server itself from attack. The host security problem is important because attackers know to attack the weakest link, which is vulnerable servers. The problem is hard because securing a server requires(More)
Buffer overflows have been the most common form of security vulnerability for the last ten years. More over, buffer overflow vulnerabilities dominate the area of remote network penetration vulnerabilities, where an anonymous Internet user seeks to gain partial or total control of a host. If buffer overflow vulnerabilities could be effectively eliminated, a(More)
Typical shared-memory multiprocessor OS kernels use interlocking, implemented as spin-locks or waiting semaphores. We have implemented a complete multiprocessor OS kernel, including threads, virtual memory, and I/O (including a window system and a file system), using only lockfree synchronization methods based on Compare-and-Swap. Lock-free synchronization(More)
The large size and high complexity of security-sensitive applications and systems software is a primary cause for their poor testability and high vulnerability. One approach to alleviate this problem is to extract the security-sensitive parts of application and systems software, thereby reducing the size and complexity of software that needs to be trusted.(More)
Server consolidation based on virtualization is an important technique for improving power efficiency and resource utilization in cloud infrastructures. However, to ensure satisfactory performance on shared resources under changing application workloads, dynamic management of the resource pool via online adaptation is critical. The inherent tradeoffs(More)
The emergence of streaming multimedia players provides users with low latency audio and video content over the Internet. Providing high-quality, best e ort, real-time multimedia content requires adaptive delivery schemes that fairly share the available network bandwidth with reliable data protocols. Real-time multimedia tra c must avoid halting TCP-based(More)
Virtualization is an essential technology in modern datacenters. Despite advantages such as security isolation, fault isolation, and environment isolation, current virtualization techniques do not provide effective performance isolation between virtual machines (VMs). Specifically, hidden contention for physical resources impacts performance differently in(More)