Hewlett-Packard

About: Hewlett-Packard is a company organization based out in Palo Alto, California, United States. It is known for research contribution in the topics: Signal & Substrate (printing). The organization has 34663 authors who have published 59808 publications receiving 1467218 citations. The organization is also known as: Hewlett Packard & Hewlett-Packard Company.

Mahout: Low-overhead datacenter traffic management using end-host-based elephant detection

Abstract: Datacenters need high-bandwidth interconnection fabrics. Several researchers have proposed highly-redundant topologies with multiple paths between pairs of end hosts for datacenter networks. However, traffic management is necessary to effectively utilize the bisection bandwidth provided by these topologies. This requires timely detection of elephant flows—flows that carry large amount of data—and managing those flows. Previously proposed approaches incur high monitoring overheads, consume significant switch resources, and/or have long detection times. We propose, instead, to detect elephant flows at the end hosts. We do this by observing the end hosts's socket buffers, which provide better, more efficient visibility of flow behavior. We present Mahout, a low-overhead yet effective traffic management system that follows OpenFlow-like central controller approach for network management but augments the design with our novel end host mechanism. Once an elephant flow is detected, an end host signals the network controller using in-band signaling with low overheads. Through analytical evaluation and experiments, we demonstrate the benefits of Mahout over previous solutions.

Pinatubo: a processing-in-memory architecture for bulk bitwise operations in emerging non-volatile memories

Abstract: Processing-in-memory (PIM) provides high bandwidth, massive parallelism, and high energy efficiency by implementing computations in main memory, therefore eliminating the overhead of data movement between CPU and memory. While most of the recent work focused on PIM in DRAM memory with 3D die-stacking technology, we propose to leverage the unique features of emerging non-volatile memory (NVM), such as resistance-based storage and current sensing, to enable efficient PIM design in NVM. We propose Pinatubo1, a Processing In Non-volatile memory ArchiTecture for bUlk Bitwise Operations. Instead of integrating complex logic inside the cost-sensitive memory, Pinatubo redesigns the read circuitry so that it can compute the bitwise logic of two or more memory rows very efficiently, and support one-step multi-row operations. The experimental results on data intensive graph processing and database applications show that Pinatubo achieves a ∼500 x speedup, ∼28000x energy saving on bitwise operations, and 1.12× overall speedup, 1.11× overall energy saving over the conventional processor.

System and method for accessing a storage area network as network attached storage

Abstract: A method, system, and apparatus for accessing a plurality of storage devices in a storage area network (SAN) as network attached storage (NAS) in a data communication network is described A SAN server includes a first interface and a second interface The first interface is configured to be coupled to the SAN The second interface is coupled to a first data communication network A NAS server includes a third interface and fourth interface The third interface is configured to be coupled to a second data communication network The fourth interface is coupled to the first data communication network The SAN server allocates a first portion of the plurality of storage devices in the SAN to be accessible through the second interface to at least one first host coupled to the first data communication network The SAN server allocates a second portion of the plurality of storage devices in the SAN to the NAS server The NAS server configures access to the second portion of the plurality of storage devices to at least one second host coupled to the second data communication network

Some aspects of the theory and measurement of frequency fluctuations in frequency standards

Abstract: Precision quartz oscillators have three main sources of noise contributing to frequency fluctuations: thermal noise in the oscillator, additive noise contributed by auxiliary circuitry such as AGC, etc., and fluctuations in the quartz frequency itself as well as in the reactive elements associated with the crystal, leading to an f-1type of power spectral density in frequency fluctuations. Masers are influenced by the first two types of noise, and probably also by the third. The influence of these sources of noise on frequency fluctuation vs. averaging time measurements is discussed. The f-1-spectral density leads to results that depend on the length of time over which the measurements are made. An analysis of the effects of finite observation time is given. The characteristics of both passive and active atomic standards using a servo-controlled oscillator are discussed. The choice of servo time constant influences the frequency fluctuations observed as a function of averaging time and should be chosen for best performance with a given quartz oscillator and atomic reference. The conventional methods of handling random signals, i.e., variances, autocorrelation, and spectral densities, are applied to the special case of frequency and phase fluctuations in oscillators, in order to obtain meaningful criteria for specifying oscillator frequency stability. The interrelations between these specifications are developed in the course of the paper.