Network Working Group H. Song
Internet-Draft Huawei
Intended status: Standards Track Z. Lv
Expires: April 22, 2010 Fudan University
October 19, 2009
A Survey of in-network storage systems
draft-song-decade-survey-00
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Abstract
This document describes how the existing in-network storage systems
work and the related protocols in use, to evaluate their suitability
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for DECADE.
Table of Contents
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . . 3
2. Terminology and Concepts . . . . . . . . . . . . . . . . . . . 3
3. Existing In-network Storage Solutions . . . . . . . . . . . . . 3
3.1. P2P Cache . . . . . . . . . . . . . . . . . . . . . . . . . 3
3.2. Web Cache . . . . . . . . . . . . . . . . . . . . . . . . . 4
3.3. CDN . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4
3.4. NFS . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4
3.5. Others . . . . . . . . . . . . . . . . . . . . . . . . . . 5
4. Security Considerations . . . . . . . . . . . . . . . . . . . . 5
5. Discussion . . . . . . . . . . . . . . . . . . . . . . . . . . 5
6. IANA Considerations . . . . . . . . . . . . . . . . . . . . . . 5
7. Acknowledgments . . . . . . . . . . . . . . . . . . . . . . . . 5
8. References . . . . . . . . . . . . . . . . . . . . . . . . . . 5
8.1. Normative References . . . . . . . . . . . . . . . . . . . 5
8.2. Informative References . . . . . . . . . . . . . . . . . . 6
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . . 6
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1. Introduction
This document describes how the existing in-network storage systems
work and the related protocols in use, to evaluate their suitability
for DECADE.
The document is a work in progress, and will be updated to include
technical details for the related work.
2. Terminology and Concepts
The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT",
"SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this
document are to be interpreted as described in [RFC2119].
This document uses terms defined in
[I-D.song-decade-problem-statement].
3. Existing In-network Storage Solutions
3.1. P2P Cache
P2P Caches are used to reduce the bandwidth problem of ISP. For
transparent cache, it has the following features:
o Allows P2P content to be cached and supplied locally such that
network traffic is reduced.
o Cache is required to support P2P protocols.
o Use of Deep Packet Inspection means no discovery needed by
application.
Non-transparent P2P cache has the following features:
o Allows P2P content to be cached and supplied locally such that
network traffic is reduced.
o Cache is required to support P2P protocols.
o Cache pretends to be normal peers.
However, both transparent and non-transparent P2P caches have the
following drawbacks that make it not suitable for DECADE:
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o Doesn't provide resource control (bandwidth and connections).
o Does not provide a standard protocol for accessing storage.
3.2. Web Cache
Web cache is deployed between web servers and clients to save copies
of server responses for future reuse to reduce latency and network
traffic. A related protocol for P2P applications to use web cache is
HTPT. It proposes to share chunks of P2P files/streams using HTTP
protocol with cache-control headers.
Web caches have the following drawbacks pertaining to usage in
DECADE:
o Doesn't provide resource control (bandwidth and connections).
o Access control with many P2P peers is difficult.
3.3. CDN
CDNs (Akamai, Limelight, CloudFront, etc.) are widely used to
delivery contents to the network edge. It has the following
features:
o Allows content to be distributed globally.
o Push contents to network edge.
o Lower latency, reduces upstream bandwidth requirement by content
owner.
However, the following drawbacks make it not suitable for DECADE:
o Doesn't provide resource control (bandwidth and connections).
o Access control with many P2P peers is difficult.
3.4. NFS
Network File System is designed to operate the file in the network.
o NFS allows a user on a client computer to access files over a
network in a manner similar to how local storage is accessed.
o pNFS allows clients to access storage devices directly and in
parallel.
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However, the following drawbacks make it not suitable for DECADE:
o Doesn't provide resource control (bandwidth and connections).
o Access control with many P2P peers is difficult.
3.5. Others
There are other systems providing in-network storage to end users.
For example, Amazon S3 [reference] provides Online storage service.
Users create buckets and buckets contain stored objects. Users can
send the buckets to the network storage or retrieve it. It is
popular backend storage for other services. But it does not provide
resource control (bandwidth and connections) as it is not designed
for P2P use.
OcenStore is another storage platform. It provides:
o Globally distributed storage.
o Multiple storage providers pool resources together.
o Focus on resiliency.
However, it doesn't provide resource control (bandwidth and
connections).
4. Security Considerations
5. Discussion
6. IANA Considerations
7. Acknowledgments
8. References
8.1. Normative References
[RFC2119] Bradner, S., "Key words for use in RFCs to Indicate
Requirement Levels", BCP 14, RFC 2119, March 1997.
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8.2. Informative References
[I-D.song-decade-problem-statement]
Yongchao, S., Zong, N., Yang, Y., and R. Alimi, "DECoupled
Application Data Enroute (DECADE) Problem Statement",
draft-song-decade-problem-statement-00 (work in progress),
October 2009.
Authors' Addresses
Song Haibin
Huawei
Baixia Road No. 91
Nanjing, Jiangsu Province 210001
P.R.China
Phone: +86-25-84565867
Email: melodysong@huawei.com
Zhihui Lv
Fudan University
Email: lzh@fudan.edu.cn
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