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Existing empirical studies of Internet structure and path properties indicate that the Internet is tree-like. This work quantifies the degree to which at least two important Internet measures--latency and bandwidth--approximate tree metrics. We evaluate our ability to model end-to-end measures using tree embeddings by actually building tree representations.(More)
SSDs exhibit very different failure characteristics compared to hard drives. In particular, the bit error rate (BER) of an SSD climbs as it receives more writes. As a result, RAID arrays composed from SSDs are subject to correlated failures. By balancing writes evenly across the array, RAID schemes can wear out devices at similar times. When a device in the(More)
Choosing a cloud storage system and specific operations for reading and writing data requires developers to make decisions that trade off consistency for availability and performance. Applications may be locked into a choice that is not ideal for all clients and changing conditions. Pileus is a replicated key-value store that allows applications to declare(More)
CORFU 1 organizes a cluster of flash devices as a single, shared log that can be accessed concurrently by multiple clients over the network. The CORFU shared log makes it easy to build distributed applications that require strong consistency at high speeds, such as databases, transactional key-value stores, replicated state machines, and metadata services.(More)
We present Griffin, a hybrid storage device that uses a hard disk drive (HDD) as a write cache for a Solid State Device (SSD). Griffin is motivated by two observations: First, HDDs can match the sequential write bandwidth of mid-range SSDs. Second, both server and desktop work-loads contain a significant fraction of block overwrites. By maintaining a(More)
Distributed systems are easier to build than ever with the emergence of new, data-centric abstractions for storing and computing over massive datasets. However, similar abstractions do not exist for storing and accessing meta-data. To fill this gap, Tango provides developers with the abstraction of a replicated, in-memory data structure (such as a map or a(More)
We introduce a novel measure called ε-four-pointscondition (ε-4PC), which assigns a value ε ∈ [0,1] to every metric space quantifying how close the metric is to a tree metric. Data-sets taken from real Internet measurements indicate remarkable closeness of Internet latencies to tree metrics based on this condition. We study embeddings(More)
CORFU is a global log which clients can append-to and read-from over a network. Internally, CORFU is distributed over a cluster of machines in such a way that there is no single I/O bottleneck to either appends or reads. Data is fully replicated for fault tolerance, and a modest cluster of about 16--32 machines with SSD drives can sustain 1 million 4-KByte(More)
The global network of datacenters is emerging as an important distributed systems paradigm — commodity clusters running high-performance applications, connected by high-speed 'lambda' networks across hundreds of milliseconds of network latency. Packet loss on long-haul networks can cripple application performance — a loss rate of 0.1% is sufficient to(More)
PLATO is a predictive total ordering protocol designed for low-latency multicast in datacenters. It predicts out-of-order arrival of multicast packets by observing their inter-arrival times, and delays packets before passing them up to the application only if it believes the packets to have arrived in the wrong order. We show through experimentation on real(More)