ICONA: Inter Cluster ONOS Network Application

Several Network Operating Systems (NOS) have been proposed in the last few years for Software Defined Networks; however, a few of them are currently offering the resiliency, scalability and high availability required for production environments. Open Networking Operating System (ONOS) is an open source NOS, designed to be reliable and to scale up to thousands of managed devices. It supports multiple concurrent instances (a cluster of controllers) with distributed data stores. A tight requirement of ONOS is that all instances must be close enough to have negligible communication delays, which means they are typically installed within a single datacenter or a LAN network. However in certain wide area network scenarios, this constraint may limit the speed of responsiveness of the controller toward network events like failures or congested links, an important requirement from the point of view of a Service Provider. This paper presents ICONA, a tool developed on top of ONOS and designed in order to extend ONOS capability in network scenarios where there are stringent requirements in term of control plane responsiveness. In particular the paper describes the architecture behind ICONA and provides some initial evaluation obtained on a preliminary version of the tool.Comment: Paper submitted to a conferenc

Flexible, wide-area storage for distributed systems using semantic cues

Thesis (Ph. D.)--Massachusetts Institute of Technology, Dept. of Electrical Engineering and Computer Science, 2009.This electronic version was submitted by the student author. The certified thesis is available in the Institute Archives and Special Collections.Cataloged from student submitted PDF version of thesis.Includes bibliographical references (p. 81-87).There is a growing set of Internet-based services that are too big, or too important, to run at a single site. Examples include Web services for e-mail, video and image hosting, and social networking. Splitting such services over multiple sites can increase capacity, improve fault tolerance, and reduce network delays to clients. These services often need storage infrastructure to share data among the sites. This dissertation explores the use of a new file system (WheelFS) specifically designed to be the storage infrastructure for wide-area distributed services. WheelFS allows applications to adjust the semantics of their data via semantic cues, which provide application control over consistency, failure handling, and file and replica placement. This dissertation describes a particular set of semantic cues that reflect the specific challenges that storing data over the wide-area network entails: high-latency and low-bandwidth links, coupled with increased node and link failures, when compared to local-area networks. By augmenting a familiar POSIX interface with support for semantic cues, WheelFS provides a wide-area distributed storage system intended to help multi-site applications share data and gain fault tolerance, in the form of a distributed file system. Its design allows applications to adjust the tradeoff between prompt visibility of updates from other sites and the ability for sites to operate independently despite failures and long delays. WheelFS is implemented as a user-level file system and is deployed on PlanetLab and Emu-lab.(cont.) Six applications (an all-pairs-pings script, a distributed Web cache, an email service, large file distribution, distributed compilation, and protein sequence alignment software) demonstrate that WheelFS's file system interface simplifies construction of distributed applications by allowing reuse of existing software. These applications would perform poorly with the strict semantics implied by a traditional file system interface, but by providing cues to WheelFS they are able to achieve good performance. Measurements show that applications built on WheelFS deliver comparable performance to services such as CoralCDN and BitTorrent that use specialized wide-area storage systems.by Jeremy Andrew Stribling.Ph.D

MPWide: a light-weight library for efficient message passing over wide area networks

We present MPWide, a light weight communication library which allows efficient message passing over a distributed network. MPWide has been designed to connect application running on distributed (super)computing resources, and to maximize the communication performance on wide area networks for those without administrative privileges. It can be used to provide message-passing between application, move files, and make very fast connections in client-server environments. MPWide has already been applied to enable distributed cosmological simulations across up to four supercomputers on two continents, and to couple two different bloodflow simulations to form a multiscale simulation.Comment: accepted by the Journal Of Open Research Software, 13 pages, 4 figures, 1 tabl

TALON - The Telescope Alert Operation Network System: Intelligent Linking of Distributed Autonomous Robotic Telescopes

The internet has brought about great change in the astronomical community, but this interconnectivity is just starting to be exploited for use in instrumentation. Utilizing the internet for communicating between distributed astronomical systems is still in its infancy, but it already shows great potential. Here we present an example of a distributed network of telescopes that performs more efficiently in synchronous operation than as individual instruments. RAPid Telescopes for Optical Response (RAPTOR) is a system of telescopes at LANL that has intelligent intercommunication, combined with wide-field optics, temporal monitoring software, and deep-field follow-up capability all working in closed-loop real-time operation. The Telescope ALert Operations Network (TALON) is a network server that allows intercommunication of alert triggers from external and internal resources and controls the distribution of these to each of the telescopes on the network. TALON is designed to grow, allowing any number of telescopes to be linked together and communicate. Coupled with an intelligent alert client at each telescope, it can analyze and respond to each distributed TALON alert based on the telescopes needs and schedule.Comment: Presentation at SPIE 2004, Glasgow, Scotland (UK