BOF on NETWORK QUALITY OF SERVICE APPLIED TO THE GRID

Transcription

1 BOF on NETWORK QUALITY OF SERVICE APPLIED TO THE GRID GGF4 Toronto, Feb 19 Tiziana Ferrari Network Quality of Service Applied to the GRID, GGF4 Toronto 1

2 1. Motivation and overview, T.Ferrari 2. QoS: Requirements and Services Proposed Agenda 2.1 GRID application requirements and services, T.Ferrari 10 min 2.2 Applicability of the Scavenger service to the GRID, V.Sander 10 min 2.3 Experiences and results from implementing the QBone 10 min Scavenger service, L.Cottrell 3. QoS to the application and/or GRID middleware: Network Advance Reservation 3.1 Results from BOF on Grid Resource Management Protocol, V.Sander 10 min 3.2 Advanced services of a grid-enabled BB, V.Sander 10 min 3.3 Current development plans of GARA, V.Sander 10 min 4. Discussion 30 min Tiziana Ferrari Network Quality of Service Applied to the GRID, GGF4 Toronto 2

3 Motivation GOAL: QoS applied to the GRID to identify network services of particular interest to the GRID (middlware and applciations) to verify the applicability of network services to the GRID to identify open issues and areas of interest for a Working Group (or Research group) Network Quality of Service: Wide and active research field since several years ago, mature enough to eventually move into production networks (packet scheduling, classification and marking and related performance, aggregation issues,delay and IPDV minimization, etc) Rich range of functionalities to be used for optmised resource utilization GRID services optimisation application adaptation Other Tiziana Ferrari Network Quality of Service Applied to the GRID, GGF4 Toronto 3

4 Some areas Network Quality of Service for GRIDs What services (Per-Hop Behaviours) - not currently addressed by ISPs and IETF are particularly requested by GRID-enabled user applications and GRID middlware? Advance reservation: linking QoS functionalities and services with GRID middleware and user applications for a more dynamic use of network services Technical issues to be addressed for the design and implementation of a Network Resource Broker in a true inter-domain environment Differentiated service and Intergrated Services (IETF) Other approaches: MPLS LSPs, optical networking and lambda switching Tiziana Ferrari Network Quality of Service Applied to the GRID, GGF4 Toronto 4

5 QoS: Requirements and Services Tiziana Ferrari Network Quality of Service Applied to the GRID, GGF4 Toronto 5

6 Services Extremely wide range of requirements due to the variety of potential GRID-aware applications (1) Videoconferencing, remote visualization, real-time remote analysis of images, tele-immersion: Packet loss frequency, one-way delay, IPDV Expedited Forwarding (2) Data-oriented applications accessing large amounts of small data portions (remote file analysis: HEP applications, earth observation,...), remote hardware control, client/server transactions in GRID middlware: Number of completed transactions over time, RTT, packet loss, packet loss pattern Assured Forwarding for minimum guaranteed bandwidth, Active queue management: ECN, WRED Tiziana Ferrari Network Quality of Service Applied to the GRID, GGF4 Toronto 6

7 Services (cont) (3) Bulk data transfer (database replication, distribution of large data collections): Guaranteed minimum bandwidth, packet loss minimisation for improved performance at high-speed TCP stack tuning in case of no bandwidth contention (or link capacity under-utilization) for increased rate aggressiveness, application adaptation, dynamic selection of single stream/parallel streams data transfer, Active queue management, other... Tiziana Ferrari Network Quality of Service Applied to the GRID, GGF4 Toronto 7

8 Services (cont) Requires a very good understanding of existing high-speed infrastructures: aggregation issues effect of systematic errors like router and OS bugs frequency of short and long-term congestion tolerance to burstiness of aggregate TCP streams More research needed for:» Token bucket depth configuration of policers» right tuning of queue lengths for maximum tolerance to burstiness» re-shaping: benefits (controlled burstiness) and penalties (additional queueing stages and consequent delay and buffer size tuning issues) Requirements not well address by network services and ISPs, still needs a lot of work Tiziana Ferrari Network Quality of Service Applied to the GRID, GGF4 Toronto 8

9 Services (cont) (4) Test applications and test traffic: Non-intrusiveness in case of congestion or in presence of background legacy traffic Less than Best-Effort Services Other? Tiziana Ferrari Network Quality of Service Applied to the GRID, GGF4 Toronto 9

10 Services today QBone Premium service (Abilene) IP Premium GEANT, alpha-phase testing Some European NRNs (not all of them for the moment) Less than Best-Effort services: QBSS (Abilene) Issues: Inter-domain seamless QoS support, for consistent end-to-end services Control of access to services (authorization, authentication is needed) Service monitoring Feedback to applications of current service level (end-to-end), application adaptation Interest from many research ISPs in killing applications and in new service models Tiziana Ferrari Network Quality of Service Applied to the GRID, GGF4 Toronto 10