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 Status of this Memo This Internet-Draft is submitted to IETF in full conformance with the provisions of BCP 78 and BCP 79. Internet-Drafts are working documents of the Internet Engineering Task Force (IETF), its areas, and its working groups. Note that other groups may also distribute working documents as Internet- Drafts. Internet-Drafts are draft documents valid for a maximum of six months and may be updated, replaced, or obsoleted by other documents at any time. It is inappropriate to use Internet-Drafts as reference material or to cite them other than as "work in progress." The list of current Internet-Drafts can be accessed at http://www.ietf.org/ietf/1id-abstracts.txt. The list of Internet-Draft Shadow Directories can be accessed at http://www.ietf.org/shadow.html. This Internet-Draft will expire on April 22, 2010. Copyright Notice Copyright (c) 2009 IETF Trust and the persons identified as the document authors. All rights reserved. This document is subject to BCP 78 and the IETF Trust's Legal Provisions Relating to IETF Documents in effect on the date of publication of this document (http://trustee.ietf.org/license-info). Please review these documents carefully, as they describe your rights and restrictions with respect to this document. Abstract This document describes how the existing in-network storage systems work and the related protocols in use, to evaluate their suitability Song & Lv Expires April 22, 2010 [Page 1] Internet-Draft DECADE Survey October 2009 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 Song & Lv Expires April 22, 2010 [Page 2] Internet-Draft DECADE Survey October 2009 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: Song & Lv Expires April 22, 2010 [Page 3] Internet-Draft DECADE Survey October 2009 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. Song & Lv Expires April 22, 2010 [Page 4] Internet-Draft DECADE Survey October 2009 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. Song & Lv Expires April 22, 2010 [Page 5] Internet-Draft DECADE Survey October 2009 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 Song & Lv Expires April 22, 2010 [Page 6]