Networking Research Overview Micah Beck Assoc Prof Computer
Networking Research Overview Micah Beck Assoc. Prof. , Computer Science Director, Lo. CI Laboratory University of Tennessee Sci. DAC PI Mtg 24 March 2004
Sci. DAC Networking Research Projects: Goals • Goal: Phase I – Develop data movement tools and infrastructures to support realtime data-intensive Sci. DAC applications – To develop advanced network tools enable Sci. DAC applications efficiently measure, predict, and diagnose end-to-end performance (2 projects) – To develop and deploy cyber security tools to support group collaborations in grid infrastructures • Goal: Phase II – Deploy the advanced tools developed in phase I in production infrastructures to support network intensive Sci. DAC projects
Logistical Networking: Tools, Applications & Architecture Micah Beck Jack Dongarra James S. Plank University of Tennessee Rich Wolksi University of California, Santa Barbara http: //loci. cs. utk. edu/scidac
Project Thrusts • Dongarra: Application Development Tools/Environments – Net. Solve/Grid. Solve • Wolski: Network Monitoring/Prediction – Network Weather Service • Beck & Plank: Logistical Networking Infrastructure, Middleware & Support – Internet Backplane Protocol – Logistical Runtime System
Internet Backplane Protocol • Overlay intermediate node providing services based on enriched resources – Storage: file system, RAM, disk – Transfer: TCP (std, compressed), UDP(SABUL, mcast), SAN/WAN – Processing: primitive operations (alpha) • 100 s of IBP depots deployed worldwide • 1. 4 alpha release: persistent sockets; optional authentication, usage logging
Logistical Networking Tools • Logistical Runtime System (Lo. RS) – E 2 E Services: Fault tolerance (Reed-Solomon), encryption (AES), compression, high perf. data movement strategies – Library, command line, GUI, Web tools – Ported to all compute platforms (Cray OS problems) • Logistical Backbone (L-Bone) – depot monitoring, resource discovery • Logistical Distribution Network (Lo. DN) – directory services, content distribution – Java Web Start delivery of tools
Sci. DAC Application Impact • Terascale Supernova Initiative (A. Mezzacappa, ONRL; J. Blondin, NCSU, D. Swesty, SUNY Stony Brook) – Five 1. 6 TB depots deployed at TSI sites • Energy Fusion Research (S. Klasky, PPPL) – Depots deployed on PPPL cluster nodes • Dataset transfers: O(1 TB) @ 1 -400 Mb/s – Simulations at NERSC and ORNL – Control/viz at ONRL, NCSU, Stony Brook, PPPL – Transfers span ESNet, Abilene • CS/Physics collaboration, science getting done!
TSI Site Deployment: ORNL, NCSU, SUNY Stony Brook, NERSC, UCSD
Sci. DAC Technology Impact • Spanning heterogeneous networks – Ultrascale (10 Gbps) wide area transfers require specialized systems – Optically swtiched networks (e. g DOE Science Ultra. Net) do not peer with IP • Serving scalable communities – Staging and caching at intermediate nodes – Processing data “in transit” • Common services on distributed data
Transit Networking Architecture Application Transport … Network IP common interface Transit Local Physical link transfer storage processing
INCITE – Edge-based Traffic Processing for High-Performance Networks R. Baraniuk, E. Knightly, R. Nowak, R. Riedi Rice University L. Cottrell, J. Navratil, W. Mathews SLAC W. Feng, M. Gardner LANL web site: incite. rice. edu
INCITE Project • Inter. Net Control and Inference from The Edge on-line tools to characterize and map host and network performance as a function of time, space, application, protocol, and service
INCITE Thrusts and Tools Thrust 1: Multiscale traffic analysis and modeling techniques » wavelet, multifractal, connection-level models Thrust 2: Inference and control algorithms for network paths, links, and routers » end-to-end path probing and modeling » network tomography and topology discovery » advanced high-speed protocols Thrust 3: Data collection tools » active measurement infrastructure » passive application-layer measurement
path. Chirp • Goal – estimate instantaneous available bandwidth (ABW) on an end-to-end network link • Basic probing paradigm – stream packets at some rate • no queuing delay rate<ABW • queuing delay builds up rate>ABW • Until now: tradeoff – high accuracy has required high volume probing (inefficient) • Unique to path. Chirp – variable rate probe packet train (exponentially spaced chirp) – 10 x more efficient than competing techniques
Network Tomography From end-to-end measurements… … infer internal topology and delay/loss characteristics
TCP - Low Priority • Goal – utilize excess bandwidth in a non-intrusive fashion • Methodology – sender-side modification of TCP: delay-based approach • Applications – bulk data transfers – available bandwidth monitoring – P 2 P file sharing • High-speed TCP-LP – TCP-LP + HSTCP – implementation • Linux-2. 4. 22 -web 100 – experiments • Stanford - Ann Arbor • Stanford - Gainesville • TCP alone • TCP plus TCP-LP 745. 5 Kb/s 739. 5 Kb/s 109. 5 Kb/s • TCP-LP is invisible to TCP
Changes in network topology (BGP) can result in dramatic changes in performance Remote host Hour s) bp (100 M s o t t e Los-N Samples of traceroute trees generated from the table Snapshot of traceroute summary table Mbits/s Note: 1. Caltech misrouted via Los-Nettos 100 Mbps commercial net 14: 00 -17: 00 2. ESnet/GEANT working on routes from 2: 00 to 14: 00 Drop in performance Back to original path Dynamic BW capacity (DBC) (From original path: SLAC-CENIC-Caltech to SLAC-Esnet-Los. Nettos (100 Mbps) -Caltech ) Changes detected by IEPM-Iperf and Ab. WE Available BW = (DBC-XT) Cross-traffic (XT) Esnet-Los. Nettos segment in the path (100 Mbits/s) ABw. E measurement one/minute for 24 hours Thursday 9 October 9: 00 am to Friday 10 October 9: 01 am
Crossing the Application/Network Divide Send data over network Application Segmentation Flow & Congestion Control TCP Checksums Fragmentation : : IP Data Link Network • Implications to the application? • Insights for highperformance network protocols? Network monitors focus here.
TICKET and MAGNET+MUSE TICKET: Traffic Information-Collecting Kernel with Exact Timing MAGNe. T: Monitor for Application-Generated Network Traffic MUSE: MAGNET User-Space Environment Send data over network Application MUSE TCP M A G N E T Segmentation Flow & Congestion Control Checksums Fragmentation : : For more information, go to www. lanl. gov/radiant/pubs. html IP Data Link Network TICKET: tcpdump++
MAGNe. T MAGNET Monitoring Apparatus for General ker. Nel-Event Tracing (at nanoscale granularity) • Why not extend monitoring to kernel events in general? Software Oscilloscope for Cluster and Grids – Debugging • e. g. , Identified. Linux OS bug in the scheduler for SMPs. • Can be used to deploy, debug, and monitor the DOE Ultra. Net (Ultra. Science. Net), e. g. , dynamic provisioning. – Performance Optimization • Improved performance of 10 Gig. E adapters by 300%. Can improve end-to-end performance of DOE Ultra. Net. – Monitoring Grid Applications • Integrated MAGNET with Sci. DAC’s PERC TAU and Sci. DAC’s PERC Sv. Pablo/Autopilot. * – Adaptive Resource-Aware Applications • Sci. DAC Deployment: PERC, Supernova Science Ctr, Transit Network Fabric + Terascale Supernova Initiative + Fusion Energy (emerging), and Earth Systems Grid II (emerging). * For more information, see M. Gardner, W. Deng, T. Markham, C. Mendes, W. Feng, and D. Reed, “A High-Fidelity Software Oscilloscope for Globus, ” Globus. World 2004, Jan. 2004.
Bandwidth estimation: measurement methodologies and applications k claffy (CAIDA), Constantinos Dovrolis (Georgia Tech)
Project goals • • • Develop estimation techniques and public-domain tools for the estimation of end-to-end: 1. Network capacity (bottleneck bandwidth) 2. Available bandwidth (residual capacity) Focus 1: non-intrusive, fast, and accurate techniques Focus 2: high-bandwidth paths (up to 1 Gbps) Compare and validate different tools in reproducible and realistic net conditions Apply bandwidth estimation in transport and overlay routing problems Disseminate research results at conferences and journals
Main accomplishments • Pathrate: capacity estimation tool – Based on packet pairs and trains – Publication: Transactions on Networking, to appear in 2004, and Infocom 2001 • Pathload: available bandwidth estimation tool – Based on self-loading periodic streams – Publications at ACM SIGCOMM 02 and PAM 2002 • Both tools are available at: www. pathrate. org – About 200 downloads per month (and increasing) • Able to measure up to 1 Gbps paths, even in the presence of interrupt coalescence – See publication at PAM 2004 • 1 st Bandwidth Estimation workshop at CAIDA, Dec’ 03
Main accomplishments (cont’) • Created testbed at CAIDA with several high-bw routers and switches and realistic cross traffic – Tested all existing open-source bandwidth estimation tools – Showed that, despite that several such tools exist, very few are accurate and consistent • Developed estimation technique for passive capacity estimation – See publications at IMC 2003 and PAM 2004 • Showed that per-hop capacity estimation tools (pathchar-like) are not accurate in the presence of layer-2 switches – See publication at Infocom 2003 • Created ANEMOS, a distributed system for automated on-line monitoring of many network paths – See publication at PAM 2003
Ongoing work • Created SOBAS, an automatic socket buffer sizing technique based on available bandwidth estimation – Basic idea: limit TCP window based on available bandwidth before the connection causes losses – Does not require changes in TCP • Develop estimation technique for the variation range of available bandwidth in different time scales – Variation range is crucial for some applications, including overlay routing • Evaluate the predictability of available bandwidth process in Internet traffic – How far in the future can we predict the avail-bw with a given accuracy? • Use of bandwidth estimation in overlay network routing and in Ultra. Science. Net dynamic optical circuit bandwidth provisioning
Security and Policy for Group Collaboration http: //www. mcs. anl. gov/dsl/scidac/security/ • PIs: – Steven Tuecke (ANL) – Carl Kesselman (USC/ISI) – Miron Livny (U. Wisconsin) • Technologies involved: – Globus Toolkit – Condor
Problem • Scalable, fine-grain policy management for large, dynamic collaborations: – Large number of individually managed resources, each with own policies – Large number of users – Users and resources in different domains – Community policies on use of resources
Goals of this Project • Design, develop and standardize tools for maintaining structure of a collaboration – Take into account collaboration policy, user privileges, site policies, resource policies, etc. • Improve significantly the integration of local security environments – E. g. , Kerberos • Instantiate our research results into a framework that makes it useable to a wide range of collaborative tools – Globus Toolkit, Condor • Work within standards community to socialize and standardize our approaches – GGF, IETF, OASIS
Engage with communities Our Process Get feedback Design and develop solutions Integrate into community software Standardize solutions for greater acceptance Evaluate and guide emerging standards
Delivered Solutions • Fine-grained Policy R&D: – Community Authorization Service – Dynamic Policy Reconciliation • Site Security Integration: – KCA/Kx 509 – Authorization Callouts • Grid Security Usability: – Simple. CA /Online CA / Mini. CA – Online Credential Repository
Standards and Implementations • X. 509 Proxy Certificates • GSSAPI extensions • Policy work: SAML, XACML • Policy Reconciliation
- Slides: 31