Transcript PowerPoint - OptIPuter

Optiputer High Performance Transport
Protocols & Implementation Plans
Ryan X. Wu, Andrew A. Chien, Eric Weigle, Nut Taesombut
CSAG, CSE, UCSD
01/25/2005
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High Performance Transport Problem
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OptIPuter is Bridging the Gap Between High Speed Link Technologies and
Growing Demands of Advanced Applications
Transport Protocols Are the Weak Link
– TCP Has Well-Documented Problems That Militate Against its Achieving High
Speeds
– OptIPuter Pursuing Range of Transport Protocols
– Shared, Routed Infrastructure:
– XCP [USC/ISI],
– UDT [Gu&Grossman, UIC]
– Provisioned Lambda:
– RBUDP/LambdaStream [He&Xiong&Leigh, EVL, UIC]
– GTP [Wu&Chien, UCSD]
– Cluster-based:
– CEP [Weigle&Chien, UCSD]
– How to make applications utilize these protocols?
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OptIPuter Transport Protocol Implementation/Integration
– Goal: Flexibility of Protocol Choices under Single Application Implementation
– Solution: Globus/XIO
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Optiputer High Performance
Transport Protocols
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RBUDP/LambdaStream
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Suitable for continuous data intensive applications.
Quickly grasp the underlying bandwidth and maintain very low jitter.
More in Eric He’s talk
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[He&Xiong&Leigh, EVL/UIC]
XCP for High BDP Networks – Shared, Routed
Environment
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Systematic Implementation and Evaluation
– Build/Test FreeBSD Kernel implementation, Performance Evaluation
– Full protocol specification and mature the protocol
– Work with the community (researchers, applications developers, users, vendors,
operators, IETF), To Develop Deployment plan
– Initial Results are Promising: Match Simulations
TCP Measured
XCP Measured
[Bannister&Falk, USC-ISI]
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UDT: UDP-based Data Transport Protocol
• UDP-based Data Transfer Protocol
-- Successor of SABUL
• Congestion/Flow Control
-- For shared networks
-- Configurable congestion control
• Implementation
-- User space: no need for root privilege or kernel recompilation
-- Socket API (will also provide XIO API soon)
-- Open source: udt.sf.net
[GU&Grossman, UIC]
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GTP: Group Transport Protocol:
Receiver-based Congestion Management
• Request-response for Reliable Data Transfer
• Single Flow Adaptation and Capacity Estimation
• Receiver-based Flow Scheduling for Fairness and Low Loss Rate
– Balance Concurrent Data Fetching from Multiple Sources
– Fair across Varied Sender RTTs
– Efficient Transitions under Rapid Changes
Applications
GTP
…...
Single Flow
Control and
Monitoring
Centralized Rate Allocation
R1
R2
UDP (data flow) / TCP (control flow)
IP
Multipoint-to-point contention at receivers
GTP Receiver Architecture
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[Wu & Chien, UCSD]
CEP: Composite Endpoint Protocol
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We need a High-performance, scalable, robust,
flexible, adaptive, easy-to-use mechanism to
terminate disproportionately large data
transfers.
User controls transfer through simple socketslike interface, and transfer constraint
specification.
– Can emulate GridFTP, MPI-IO, and parallel
filesystem interfaces easily.
CEP handles actual transfers subject to user
constraints via scheduling mechanism
– Uses multiple cooperating nodes.
– Heterogeneous hosts may take part
unequally in a connection.
– Scheduler handles failures, fairness,
changing resources over time.
– Does the “Heavy Lifting”
– TCP, UDP, FAST, HSTCP, ... used as
underlying protocol.
[Weigle & Chien, UCSD]
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OptIPuter Transport Protocol
Implementation/Integration
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Transport Protocol Deployment Problem
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Issues:
– How to make applications utilize OptIPuter transport protocols?
– What is the relation between transport protocols and backbone management and
configuration?
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Each transport protocol has its own API and semantics
– Different targeted network environments
– Shared, routed network
– Private, or QoS-provisioned network
– Different semantics
– Blocking/non-blocking
– Point-to-point, multipoint-to-point
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Applications need to be modified to use different protocols.
– Changes may be complex
– Need to maintain multiple versions with different transport protocols
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Provide the same API for all OptIPuter transport protocols
– Allow convenient integration with applications
– Support further testing/evaluating different transport protocols
– Solution: Globus XIO: eXtensive Input Output library
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Globus/XIO
• Globus XIO user API
User API
– Single API/Single Set of semantics.
– Simple open/close/read/write API
– Hides protocol details
– Allows for extensibility
– Drivers can be selected at runtime
• XIO interface for OptIPuter transport
protocols
– A simple XIO wrapper (~1000 lines of code)
on top of each transport protocol to provide
XIO API
– Almost no changes needed to the original
protocol implementation
Framework
• Driver Abstraction
Driver Stack
Transform
Transform
Transport
XIO Framework
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XIO Example
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Init the protocol stack
– globus_xio_stack_init(&stack, NULL);
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Load drivers
– globus_xio_driver_load(“TCP", &txdriver);
– or ‘UDP’, “UDT’’, “GTP”…
– globus_xio_stack_push_driver(stack, txdriver);
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Init and set protocol attributes
– globus_xio_attr_init(&attr);
– globus_xio_attr_cntl(attr, txdriver, GLOBUS_XIO_SET_LISTENING_PORT,
hosts, numhosts);
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Create handle
– globus_xio_handle_create(&handle, stack);
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Send/receive data
– globus_xio_open(&handle, NULL, target);
– globus_xio_write(handle, "hello world\n", 12, 1, &nbytes, NULL);
– globus_xio_close(handle, NULL);
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OptIPuter Communication Software Architecture
Distributed Applications/ Web Services/Viz. Apps
High-level IPC Library (e.g., MPI, PVM)
DVC. APIs
Socket Wrapper (C and Java)
XIO Interface
GTP
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CEP
XCP
UDT
LambdaStream
DVC Descriptor
DVC Config.
Standard and Custom Communication Protocols are Accessible through a
Unique API
DVC Descriptor Provides Information about Resource Configuration,
Naming, and Other Properties
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Implementation Plan
• Current Implementation Status
– The TCP, UDP and simple UDT XIO drivers are coming with the
Globus/XIO
– GTP XIO driver is available
• Implementation and Integration Plan
– XIO driver for UDT 2.0 will be available early next month
– XIO drivers for LambdaStream and CEP are in progress
– Demonstrate applications running with different protocols via XIO
interface
– Further testing and large-scale experiments on different transport
protocols
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For More Information
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A. Falk, T. Faber, J. Bannister, A. Chien, R. Grossman, J. Leigh, Transport
protocols for high performance, Communications of the ACM, Volume 46,
Number 11, November 2003, pp. 42-49.
X. Wu and A. Chien, GTP: Group Transport Protocol for Lambda Grids, IEEE
Symposium on Cluster Computing and the Grid (CCGrid), April 2004.
Y. Gu, X. Hong, and R. Grossman, Experiences in Design and Implementation of
a High Performance Transport Protocol, (submitted for publication).
Eric Weigle and Andrew A. Chien, The Composite Endpoint Protocol (CEP):
Scalable Endpoints for Terabit Flows Submitted to CCGrid 2005.
LambdaStream
Globus XIO: http://www.globustookit.org
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