USENIX Annual Technical Conference 

About: USENIX Annual Technical Conference is an academic conference. The conference publishes majorly in the area(s): Computer science & File system. Over the lifetime, 1417 publications have been published by the conference receiving 92569 citations.

QEMU, a fast and portable dynamic translator

Abstract: We present the internals of QEMU, a fast machine emulator using an original portable dynamic translator. It emulates several CPUs (x86, PowerPC, ARM and Sparc) on several hosts (x86, PowerPC, ARM, Sparc, Alpha and MIPS). QEMU supports full system emulation in which a complete and unmodified operating system is run in a virtual machine and Linux user mode emulation where a Linux process compiled for one target CPU can be run on another CPU.

In search of an understandable consensus algorithm

Abstract: Raft is a consensus algorithm for managing a replicated log. It produces a result equivalent to (multi-)Paxos, and it is as efficient as Paxos, but its structure is different from Paxos; this makes Raft more understandable than Paxos and also provides a better foundation for building practical systems. In order to enhance understandability, Raft separates the key elements of consensus, such as leader election, log replication, and safety, and it enforces a stronger degree of coherency to reduce the number of states that must be considered. Results from a user study demonstrate that Raft is easier for students to learn than Paxos. Raft also includes a new mechanism for changing the cluster membership, which uses overlapping majorities to guarantee safety.

ZooKeeper: wait-free coordination for internet-scale systems

Abstract: In this paper, we describe ZooKeeper, a service for coordinating processes of distributed applications Since ZooKeeper is part of critical infrastructure, ZooKeeper aims to provide a simple and high performance kernel for building more complex coordination primitives at the client It incorporates elements from group messaging, shared registers, and distributed lock services in a replicated, centralized service The interface exposed by Zoo-Keeper has the wait-free aspects of shared registers with an event-driven mechanism similar to cache invalidations of distributed file systems to provide a simple, yet powerful coordination service The ZooKeeper interface enables a high-performance service implementation In addition to the wait-free property, ZooKeeper provides a per client guarantee of FIFO execution of requests and linearizability for all requests that change the ZooKeeper state These design decisions enable the implementation of a high performance processing pipeline with read requests being satisfied by local servers We show for the target workloads, 2:1 to 100:1 read to write ratio, that ZooKeeper can handle tens to hundreds of thousands of transactions per second This performance allows ZooKeeper to be used extensively by client applications

An analysis of power consumption in a smartphone

Abstract: Mobile consumer-electronics devices, especially phones, are powered from batteries which are limited in size and therefore capacity. This implies that managing energy well is paramount in such devices. Good energy management requires a good understanding of where and how the energy is used. To this end we present a detailed analysis of the power consumption of a recent mobile phone, the Openmoko Neo Freerunner. We measure not only overall system power, but the exact breakdown of power consumption by the device's main hardware components. We present this power breakdown for micro-benchmarks as well as for a number of realistic usage scenarios. These results are validated by overall power measurements of two other devices: the HTC Dream and Google Nexus One. We develop a power model of the Freerunner device and analyse the energy usage and battery lifetime under a number of usage patterns. We discuss the significance of the power drawn by various components, and identify the most promising areas to focus on for further improvements of power management. We also analyse the energy impact of dynamic voltage and frequency scaling of the device's application processor.

Design tradeoffs for SSD performance

Abstract: Solid-state disks (SSDs) have the potential to revolutionize the storage system landscape. However, there is little published work about their internal organization or the design choices that SSD manufacturers face in pursuit of optimal performance. This paper presents a taxonomy of such design choices and analyzes the likely performance of various configurations using a trace-driven simulator and workload traces extracted from real systems. We find that SSD performance and lifetime is highly workload-sensitive, and that complex systems problems that normally appear higher in the storage stack, or even in distributed systems, are relevant to device firmware.