Thorsten von EickenAssistant Professor PhD UC Berkeley, 1993My research has focused on high-performance communication in clusters of workstations. My group developed the U-Net user-level networking architecture to close the dramatic gap between the bit-rate of high-speed networks and the communication performance seen by applications. The key idea in U-Net is to virtualize the network interface, which allows each application on a multitasking computer to access the network directly without invoking the operating system. This effectively moves the protocol stack to the user-level, where it can be |
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| coupled more tightly to the application, resulting in an order-of-magnitude reduction in communication overhead. In addition, the user-level protocols can be customized to the application, thereby enabling experimentation with new protocols that are, for example, tailored toward real-time multimedia stream transmission. | |
The main ideas of U-Net have been incorporated into the VIA (Virtual Interface Architecture) industry standard led by Compaq, Intel and Microsoft. At this point, commercial network interfaces designed for VIA are becoming available.
My group is working on language-based protection, i.e. techniques to enforce protection mechanisms entirely in software using properties of programming languages, compilers, and runtime systems. We are concentrating our efforts on a Java-based system called the J-Kernel. The J-Kernel, written entirely in Java, provides an operating system infrastructure for customizable Internet servers and application-specific gateways. The primary goal of the J-Kernel is to allow users to upload custom services into servers in the network in a secure yet flexible manner. Just as Java enables Web browsers in which users "safely" download applets, the J-Kernel enables "safe" Internet servers onto which users can upload servlets. The J-Kernel relies on type safety properties of the language system in order to enforce protection boundaries between applications and the OS itself, which means that all code can run in a single address space and at a single hardware privilege level. The expected benefits of this approach are higher resource efficiency, seamless system extensibility, and flexibility in the form of fine grain sharing across protection domains.
Publications
Implementing multiple protection domains in Java. Proc. 1998 USENIX Ann. Tech. Conf., New Orleans, LA (June 1998) (with C. Hawblitzel, C. Chang, G. Czajkowski and D. Hu).
Secure and portable database extensibility. Proc. ACM SIGMOD '98 Conf., Seattle, WA (June 1998) (with M. Godfrey, S. Mayr, and P. Seshadri).
Evaluating the performance limitations of MPMD communication. Proc. SC '97, San Jose, CA (Nov. 15-19, 1997) (with C.-C Chang, G. Czajkowski, and C. Kesselman).