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Service Differentiation and Grids. Pascale V icat-Blanc Primet Benjamin Gaidioz, Pierre Billiau, François Echantillac, Mathieu Goutelle, Fabien Chanussot INRIA - Reso LIP Laboratory Ecole Normale Supérieure de Lyon France P ascale. primet@inria.fr. Outline.
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Service Differentiation and Grids Pascale Vicat-Blanc Primet Benjamin Gaidioz, Pierre Billiau, François Echantillac, Mathieu Goutelle, Fabien Chanussot INRIA - Reso LIP Laboratory Ecole Normale Supérieure de Lyon France Pascale.primet@inria.fr
Outline • Requirements for E2EService Differentiation in Grids • The EDS approach(DataTAG project) • The QoSinus approach (e-Toile/VTHD project) • Conclusion P. Vicat-Blanc Primet
Typology of Grid flows • Applications flows: • Input & Output data • Inter process communication messages (MPI, DSM, synchro…) • Codes coupling • Interactions • Vizualizations • Voice/Video in collaborative environments • Control flows: • Grid environment deployment • Applications deployment • Control and Management of the Grid (middleware) • Monitoring, scheduling, loading, reporting, alarms… • All these flows share the same « network resource » and the same bottlenecks P. Vicat-Blanc Primet
6 PC bipro 16 PC bipro Clusters de PC 1,9 Ghz Serveur bipro 1,2 Ghz Example: e-toile : Infrastructure Europe US Experimental Testbed Production Testbed ID-IMAG Grenoble ID-IMAG Grenoble ID-IMAG Grenoble ID-IMAG Grenoble ID-IMAG Grenoble ID-IMAG Grenoble ID-IMAG Grenoble 12 PC bipro 1 Gb/s 250 PC en cluster IRISA Rennes IRISA Rennes VTHD 2.5 à 10 Gb/s 2 Gb/s CERN 1 Gb/s SUN Grenoble SUN Grenoble 1 Gb/s CEA Saclay CEA Saclay CEA Saclay Serveur 8 processeurs 1 Gb/s 1 Gb/s ENS Lyon ENS Lyon ENS Lyon ENS Lyon ENS Lyon ENS Lyon 1 Gb/s PRiSM Versailles PRiSM Versailles PRiSM Versailles PRiSM Versailles EDF Clamart EDF Clamart EDF Clamart EDF Clamart EDF Clamart 8 x 2 PC linked by SCI Serveur bipro MP760 IBCP 1 cluster de PC Machine SMP 16 power PC linked by Myrinet Routeur actif Routeur actif 1 cluster Myrinet de 10 PCs 1 cluster de 8 PCs P. Vicat-Blanc Primet Service de dépôt de données IBP Serveur 3* bipro 16 Sun Cobalt
Grid Flows characteristics • Mice, Elephant, Lièvres et Tortues, … • Throughput: • Rates: more than 9 orders of magnitude • Few bytes for interactive traffic or control traffic • To petabytes for bulk data transfer. • Delay: • Very heterogeneous needs • Some applications are very sensitive to latency (MPI; visu) • Bulk Data Transfer delays have to be controlled • Reliability : • Generally reliable (=> TCP) but some apps are loss tolerant (Astro) • Communication models: • Point to point, point to multipoint, multipoint to point, multipoint to point • Collectives operations, synchronisation barriers... P. Vicat-Blanc Primet
time Medical Images processing: Pipeline tagged MRIsequences From 20MB to 2GB/frame 1. Tags and myocardium automatic extraction 2. Motion estimation 3. Quantification P. Vicat-Blanc Primet
How to control the performances? • Packet level (Network QoS) • ~1 à 100ms • Mechanisms: classifiers, marquers et conditionners (routers) • Models: IntServ, DiffServ, Corestateless,Proportional, EDS… • Round trip time level (E2E QoS) • ~1 à 100 ms • Congestion control and flow control (TCP, TFRC) • Session level • s, mn, or hr • Admission control, Resource reservation (RSVP), routing • Load sharing, MPLS-TE, BoD • Long term • Days, months... • Provisionning, planification, loD P. Vicat-Blanc Primet
Explored Approaches (INRIA RESO) • Grid really need End to end QoS (bulk to MPI & vizual.) • Packet differentiation is already there in IP equipments • PQ, WFQ, CBQ, WRR, RED, WRED… • Lot of issues with IS & Diffserv • Service differentiation at transport level • Two approaches have been explored at INRIA: • E&E : DataTAG(assumption: bottleneck is in access&LAN) • Relative IP packet differentiated forwarding • Each connectionmanages its individual QoS • End protocol has to be adapted (SlowStart or AIMD) • Edge to Edge : e-Toile(assumption : bottleneck is in WAN) • An Independant API defined and integrated in mw to specify sessionQoS goals • QoSINUS as a Grid network Service • Interact with the Grid Measurement Infrastructure P. Vicat-Blanc Primet
EDS approach P. Vicat-Blanc Primet
Equivalent Differentiated Service Model • Goal: Sharing the network resources (bottleneck) and control the E2E performances according to the application specific requirements => delay sensitive/ loss sensitive/rate sensitive… • Constraints: new PHB at IP level • Differentiated forwarding serviceswithoutpricing • No admission controlrequired. • PHB definition restricted to local parameters(no layer violation) • The transport layer has to integrate some adaptationmechanisms to contribute to end to end performance control. P. Vicat-Blanc Primet
Equivalent Differentiated Services • Proportionality • Asymmetry (cf ABE) P. Vicat-Blanc Primet
Equivalent Differentiated Services • The EDS model defines an arbitrary number Nof classes. • Differentiation on delay and loss rate for each class. • A class i gets a delay coef di and a loss rate coef li. • These coef are constants. • let i and j be two classes, the router schedules and drops their packets so that there is a ratio di/dj between local queuing delays and li/lj between local loss rates. • In order to avoid having privileged classes, coefficients are set: if di<dj then li>lj or if di>dj then li<lj for all I in [1,N] and j in [1,N] P. Vicat-Blanc Primet
Adaptive Packet Marking: simple algorithm loss delay t t Selected class Delay constraint Loss constraint P. Vicat-Blanc Primet
AIMD EDS packet marking principle P. Vicat-Blanc Primet
Validation • EDS layer3 has been implemented in NS and in the Linux QoS kernel • EDS layer 4 has been implemented in SCTP via an adaptation of the AIMD algorithm in NS and Linux kernel and tested on a local emulated platform (NistNet) and on DataTAG link P. Vicat-Blanc Primet
Results for a mix of traffic (NS simulations) EDS3/4 Real-Time traffic Latency constraint respect 2x > Interactive traffic Transfer delay <60% Bulk transfer #timeout P. Vicat-Blanc Primet
QoSINUS approach P. Vicat-Blanc Primet
e-Toile GRID project goals • Develop a Grid testbed: • On the Very High Bandwidth experimental network(VTHD) • “Active Grid Technology” (dynamicity of the grid) • Develop a middleware prototype: • Programmable Network and communication Libraries • NFSp & GXFER, MPI madeleine, MOME (DSM), • Active network services (QoS, Mcast) • Perform tests with high end applications • computing intensive,data intensive, network intensive • validation of a “high performance grid” model targeting large scale numerical simulations. P. Vicat-Blanc Primet
Back-end 1 Back-end 2 frontale … Back-end N ENS Lyon Programmable network INRIA RESO/LIP) • Active nodes TAMANOIR and IBP depot (Loci/UTK) deployed at the edge of VTHD • Gigabit supported with a TAN cluster (~1.3Gbits/s): • TAN cluster = a front-end with back-ends for load balancing Actif flow Receiver TAN CEA Paris Receiver VTHD TAN CERN Active Flow Genève P. Vicat-Blanc Primet
QoSINUS: E2E Performance controllability QoSINUS: Quality of Service Negociate, Invoke, Use • Goals: • E2E QoS : an interface « application » <-> « network » • Application QoS objective: eg. E2E transfer delay • Use Network QoS: DiffServ (packet prioritization) • A programmable service (adapt API & algorithm) • QoSinus principles • Specification and negociation of a SLS for a microflow by Grid scheduler or application • Programmable mapping of the QoS objective in a packet DSCP in the first active node (use EF, AF, BE, LBE…). • Dynamic Adaptation of packet marking based on measurement results (network and flow). P. Vicat-Blanc Primet
QoS objectives programming P. Vicat-Blanc Primet
VTHD++ plate-forme FTRD Caen IPv6 over MPLS Rouen FTRD Lannion INRIA Nancy ENST Br Brest Paris AUB IPv6inIPv4 CHU Rennes Nancy Paris STL Paris MSO INT ENST Br Rennes FTRD Rennes INRIA INRIA Rennes ENST FTRD Issy HEGP CERN CERN EDF INRIA Lyon Lyon CEA PRISM Opentransit Connectivité IPv6 INRIA Grenoble FTRD Grenoble Grenoble IPv6/IPv4 2.5Gbps Sun IMAG IPv6/IPv4 1 Gbps Juniper : M20/M40/T640 Nice FTRD Sophia IPv6/IPv4 STM1/4 Eurecom Cisco GSR 12000 INRIA Sophia IPv4 seulement Routeurs de sites VTHD++/eToile TSR Avici IPv6 sur tunnel P. Vicat-Blanc Primet
The VTHD backbone • “Really Very High Bandwidth”: • provides 1Gb/s to 2Gb/sdirect access links • Up to 4 x 2.5Gb/s in the core; • experimental network • great availability • Advanced services (Multicast, DiffServ, IPv6, MPLS, GMPLS/UNI…) • connected to other research networks in EUthrough the DataTAG link (CERN in Geneva). • The VTHD network is deployed by France Telecom • RNRT project VTHD and VTHD++ P. Vicat-Blanc Primet
DiffServ in VTHD P. Vicat-Blanc Primet
Experimental results in e-Toile/ VTHD P. Vicat-Blanc Primet
Conclusion • Diffserv philosophie provides the mean to extend the IP forwarding model with scalable and easy to deploy service differentiation mechanisms. • Difficult to avoid it if we want to control performances in GRIDS ! • Standard PHB are deployed (Premium, LBE) in EU NRNs • EDS or propDS provide simple and autonomous solutions to add differentiated services in an IP network. • An incremental solution (for access links and LANs) • Adaptive end to end transport protocols (packet marking in AIMD...) • QoSINUS exploit and control DiffServ ingress point transparently. • Provides a simple and extensible API to application (XML) • Provides a multi-domain and transparent solution P. Vicat-Blanc Primet
Future Work: Grid5000 • Measure the gain obtained with challenging grid applications and grid infrastructures. • Interaction with novel transport protocols for bulk transfers • Explore deeply the multi-domain multi-service problem • Explore the scalability of the EDS and QoSINUS approaches. • GRID5000 project : a large scale cluster interconnection in France • With about 5000 processors aggregated • With high performance DiffServ network links (RENATER) • + high performance latency emulation tools. • http://www.grid5000.org • Interconnected with GN2 P. Vicat-Blanc Primet
More info • RESO project at INRIA: http://www.ens-lyon.fr/LIP/RESO • e-Toile: http://www.urec.cnrs.fr/etoile • VTHD: http://www.vthd.org • GRID5000: http://www.grid5000.org Pascale.Primet@inria.fr P. Vicat-Blanc Primet