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Training models on large‐scale GPUs‐accelerated clusters are becoming a commonplace due to the increase in complexity and size in deep learning models. One of the main challenges for distributed training is the collective communication overhead for large message sizes: up to hundreds of MB. In this paper, we propose two hierarchical distributed memory multileader AllReduce algorithms optimized for...
Non-volatile memory (NVM) such as phase change memory is a promising technology for future low-energy and high-capacity memory systems. One of the well-known issues of NVM is its fundamental characteristics that are different from common memory subsystems with DRAM. In particular, the NVM write latency is much higher than DRAM while the NVM read latency is almost the same as DRAM. The latency asymmetry...
A message broker is an imperative component in IoT systems, and it works as a gateway between IoT devices and application platforms. With the growth of IoT devices today, these systems can easily overwhelm message brokers unless the software can fully utilize hardware resources such as multi-core facility. This paper presents muMQ, a high-performance MQTT broker running on Commercial-Off-The-Shelf...
A network latency emulator allows IT architects to thoroughly investigate how network latencies impact workload performance. Software-based emulation tools have been widely used by researchers and engineers. It is possible to use commodity server computers for emulation and set up an emulation environment quickly without outstanding hardware cost. However, existing software-based tools built in the...
A performance-assured Network Function Virtualization (NFV) method for software-based packet processing on an open and disaggregated optical transport systems will be demonstrated. Our technique improves NFV operations by leveraging cache memory allocation and monitoring.
Container technology has become popular in HPC applications because it offers easy customization and quick execution. However, container technology does not allow kernel-level optimization. It does not allow changing a kernel as well as loading/unloading a kernel module, thus it prevents the extraction of full performance on a target machine. In addition, container technology is designed for multi-tenancy...
The ability to migrate services to a remote data center is an important feature of Cloud services, especially after a natural disaster. The FELIX project has developed a global scale testbed by federating multiple, distributed, data centers, called SDN islands. FELIX leverages on a transit network resource manager (TN RM) to enable NSI and GRE connections between different SDN islands. In this study,...
Artificial Intelligence (AI)-based big data analysis is emerging for broad application fields, including manufacturing, autonomous car, health care, agriculture, and so on. Data centers are under severe pressure to meet ever-increasing demands on clouds. On the other hand, the amount of data processing is bounded by the total power budget, where the reasonable number is up to 20 MW. Therefore, the...
Manually detection of machine failures in a factory is a time-consuming and costly task. Tele-monitoring is critical to alleviate this problem and recover from failures quickly. Energy conservation of such a tele-monitoring system is an important consideration. MATEMA6 enables us to monitor and notify the machine status with rapidly and low energy consumption. It is built on top of commodity technologies:...
The energy consumption of memory is one of the important metrics to evaluate memory systems. However, previous approaches such as using cycle accurate CPU and memory simulators require a long execution time for simulation. We are developing a model of energy consumption of DRAM-and NVM-based main memory, which allows estimating the energy consumption of a memory subsystem from easily observable performance...
The feasibility of the cloud computing paradigm is examined from the High Performance Computing (HPC) viewpoint. The impact of virtualization is evaluated on our latest private cloud, the AIST Super Green Cloud, which provides elastic virtual clusters interconnected by Infini Band. Performance is measured by using typical HPC benchmark programs, both on physical and virtual cluster computing clusters...
Virtualization techniques greatly benefit cloud computing. Live migration enables a datacenter to dynamically replace virtual machines (VMs) without disrupting services running on them. Efficient live migration is the key to improve the energy efficiency and resource utilization of a datacenter through dynamic placement of VMs. Recent studies have achieved efficient live migration by deleting the...
Recently, virtualization has been an increasingly popular trend in cloud computing due to its ease of administration and efficient resource allocation. Hardware virtualization reduces the overhead of virtualization and significantly improves the performance, comparing favorably to that of physical machines. However, hardware virtualization is complicated to configure and thus is not widely used. This...
Virtual machine (VM) consolidation is an emerging solution for energy saving in cloud data centers. An appropriate VM consolidation policy must change accordingly, depending on the situation. To easily deploy a VM consolidation solution, this paper proposes a VM consolidation framework for Apache CloudStack, which is a popular open source cloud platform software suite. We separate the VM consolidation...
Live migration of virtual machines over a wide area network has many use cases such as cross-data center load balancing, low carbon virtual private clouds, and disaster recovery of IT systems. An efficient wide area live migration method is required because cross-data center connections have a narrow bandwidth. Page cache occupies a large portion of the memory of a Virtual Machine (VM) when it executes...
A virtual machine (VM) migration is useful for improving flexibility and maintainability in cloud computing environments. However, the heterogeneity of the underlying software and hardware, including CPU and interconnect architectures, makes it hard to migrate a VM. In addition, VM monitor~(VMM)-bypass I/O technologies, which significantly reduce the overhead of I/O virtualization, also make VM migration...
We have been developing a middleware suite called GridARS that enables co-allocation of computing and network resources from multiple administration sites. In such middleware, it is important to provide each user application with a slice which is a set of dynamically allocated resources distributed across sites. However, there are the following issues in constructing such a slice automatically: 1)...
An HPC cloud, a flexible and robust cloud computing service specially dedicated to high performance computing, is a promising future e-Science platform. In cloud computing, virtualization is widely used to achieve flexibility and security. Virtualization makes migration or checkpoint/restart of computing elements (virtual machines) easy, and such features are useful for realizing fault tolerance and...
In Infrastructure-as-a-Service datacenters, the placement of Virtual Machines (VMs) on physical hosts are dynamically optimized in response to resource utilization of the hosts. However, existing live migration techniques, used to move VMs between hosts, need to involve large data transfer and prevents dynamic consolidation systems from optimizing VM placements efficiently. In this paper, we propose...
Virtualized IT infrastructures combined with virtual machine migration technologies have a potential to support IT services that are resilient to partial physical infrastructure failures caused by extreme events. This paper experimentally evaluates the migration of multiple VMs across long geographical distances — an activity that is required to move virtualized IT systems from a disaster site to...
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