idnits 2.17.1 draft-dreibholz-rserpool-enrp-takeover-01.txt: Checking boilerplate required by RFC 5378 and the IETF Trust (see https://trustee.ietf.org/license-info): ---------------------------------------------------------------------------- No issues found here. Checking nits according to https://www.ietf.org/id-info/1id-guidelines.txt: ---------------------------------------------------------------------------- No issues found here. Checking nits according to https://www.ietf.org/id-info/checklist : ---------------------------------------------------------------------------- No issues found here. Miscellaneous warnings: ---------------------------------------------------------------------------- == The copyright year in the IETF Trust and authors Copyright Line does not match the current year -- The document date (January 7, 2009) is 5581 days in the past. Is this intentional? Checking references for intended status: Experimental ---------------------------------------------------------------------------- == Outdated reference: A later version (-34) exists of draft-dreibholz-rserpool-asap-hropt-03 == Outdated reference: A later version (-33) exists of draft-dreibholz-rserpool-delay-02 Summary: 0 errors (**), 0 flaws (~~), 3 warnings (==), 1 comment (--). Run idnits with the --verbose option for more detailed information about the items above. -------------------------------------------------------------------------------- 2 Network Working Group T. Dreibholz 3 Internet-Draft University of Duisburg-Essen 4 Intended status: Experimental X. Zhou 5 Expires: July 11, 2009 Hainan University 6 January 7, 2009 8 Takeover Suggestion Flag for the ENRP Handle Update Message 9 draft-dreibholz-rserpool-enrp-takeover-01.txt 11 Status of this Memo 13 This Internet-Draft is submitted to IETF in full conformance with the 14 provisions of BCP 78 and BCP 79. 16 Internet-Drafts are working documents of the Internet Engineering 17 Task Force (IETF), its areas, and its working groups. Note that 18 other groups may also distribute working documents as Internet- 19 Drafts. 21 Internet-Drafts are draft documents valid for a maximum of six months 22 and may be updated, replaced, or obsoleted by other documents at any 23 time. It is inappropriate to use Internet-Drafts as reference 24 material or to cite them other than as "work in progress." 26 The list of current Internet-Drafts can be accessed at 27 http://www.ietf.org/ietf/1id-abstracts.txt. 29 The list of Internet-Draft Shadow Directories can be accessed at 30 http://www.ietf.org/shadow.html. 32 This Internet-Draft will expire on July 11, 2009. 34 Copyright Notice 36 Copyright (c) 2009 IETF Trust and the persons identified as the 37 document authors. All rights reserved. 39 This document is subject to BCP 78 and the IETF Trust's Legal 40 Provisions Relating to IETF Documents 41 (http://trustee.ietf.org/license-info) in effect on the date of 42 publication of this document. Please review these documents 43 carefully, as they describe your rights and restrictions with respect 44 to this document. 46 Abstract 48 This document describes the Takeover Suggestion Flag for the 49 ENRP_HANDLE_UPDATE message of the ENRP protocol. 51 Table of Contents 53 1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . . 3 54 1.1. Scope . . . . . . . . . . . . . . . . . . . . . . . . . . . 3 55 1.2. Terminology . . . . . . . . . . . . . . . . . . . . . . . . 3 56 1.3. Conventions . . . . . . . . . . . . . . . . . . . . . . . . 3 57 2. Takeover Suggestion Flag . . . . . . . . . . . . . . . . . . . 3 58 2.1. Definition . . . . . . . . . . . . . . . . . . . . . . . . 4 59 3. Reference Implementation . . . . . . . . . . . . . . . . . . . 4 60 4. Security Considerations . . . . . . . . . . . . . . . . . . . . 4 61 5. IANA Considerations . . . . . . . . . . . . . . . . . . . . . . 5 62 6. References . . . . . . . . . . . . . . . . . . . . . . . . . . 5 63 6.1. Normative References . . . . . . . . . . . . . . . . . . . 5 64 6.2. Informative References . . . . . . . . . . . . . . . . . . 5 65 Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . . 6 67 1. Introduction 69 Reliable Server Pooling as described in [RFC5351] defines protocols 70 for providing highly available services. The management component 71 used for pool administration is denoted as ENRP Server or Pool 72 Registrar (PR). Since a single ENRP server constitutes a single 73 point of failure, there must be multiple ENRP servers. Servers, 74 denoted as Pool Elements (PE), use an arbitrary ENRP server for 75 registration into the pool. The chosen ENRP server becomes the Home 76 ENRP Server, also denoted as Home PR (PR-H), of the PE. It is 77 responsible for making the PE identity known to the other ENRP 78 servers (by using ENRP_HANDLE_UPDATE messages) and also to monitor 79 the PE health (by using keep-alive messages). 81 As shown in [AINA2009], the following scenario leads to unbalanced 82 ENRP server workload: consider a set of multiple ENRP servers with 83 one subset being unreliable (for example, their network connection 84 has problems) and some reliable ENRP servers. After a while, the 85 reliable ENRP server will get the home ENRP server role for almost 86 all of the PEs, which results in high workload for this ENRP server. 87 Since the home ENRP server role is more computation-intensive (as 88 shown by [IJHIT2008]), this leads to highly unbalanced workload for 89 large RSerPool setups. This unbalanced workload remains, even when 90 the unreliable ENRP servers become reliable again (for example, when 91 the network problems have been solved). 93 1.1. Scope 95 The Takeover Suggestion Flag defined in this draft defines a flag for 96 the ENRP_HANDLE_UPDATE message. If the flag is set, the receiving 97 ENRP server is suggested to take over the PE specified in the 98 ENRP_HANDLE_UPDATE message. 100 1.2. Terminology 102 The terms are commonly identified in related work and can be found in 103 the RSerPool Overview document RFC 5351 [RFC5351]. 105 1.3. Conventions 107 The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", 108 "SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this 109 document are to be interpreted as described in [RFC2119]. 111 2. Takeover Suggestion Flag 112 2.1. Definition 114 In this subsection, only the differences to the ENRP_HANDLE_UPDATE 115 message defined in [RFC5353] are explained. The following figure 116 shows the ENRP_HANDLE_UPDATE message: 118 0 1 2 3 119 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 120 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 121 | Type = 0x04 |0|0|0|0|0|0|0|T| Message Length | 122 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 123 | Sending Server's ID | 124 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 125 | Receiving Server's ID | 126 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 127 | Update Action | (reserved) | 128 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 129 : Pool Handle Parameter : 130 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 131 : Pool Element Parameter : 132 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 134 T flag: 1 bit (boolean) 136 If set, the receiving ENRP server is suggested to take over the PE 137 specified by the Pool Handle and Pool Element Parameters. It is 138 RECOMMENDED for the receiving ENRP server to perform this takeover if 139 it has the resources to do so. 141 3. Reference Implementation 143 The RSerPool reference implementation RSPLIB can be found at 144 [RSerPoolPage]. It supports the functionalities defined by 145 [RFC5351], [RFC5352], [RFC5353], [RFC5354] and [RFC5356] as well as 146 the options [I-D.dreibholz-rserpool-asap-hropt], 147 [I-D.dreibholz-rserpool-delay] and of course the option defined by 148 this document. An introduction to this implementation is provided in 149 [Dre2006]. 151 4. Security Considerations 153 Security considerations for RSerPool systems are described by 154 [RFC5355]. 156 5. IANA Considerations 158 This document does not require additional IANA actions beyond those 159 already identified in the ENRP and ASAP protocol specifications. 161 6. References 163 6.1. Normative References 165 [RFC2119] Bradner, S., "Key words for use in RFCs to Indicate 166 Requirement Levels", BCP 14, RFC 2119, March 1997. 168 [RFC5351] Lei, P., Ong, L., Tuexen, M., and T. Dreibholz, "An 169 Overview of Reliable Server Pooling Protocols", RFC 5351, 170 September 2008. 172 [RFC5352] Stewart, R., Xie, Q., Stillman, M., and M. Tuexen, 173 "Aggregate Server Access Protocol (ASAP)", RFC 5352, 174 September 2008. 176 [RFC5353] Xie, Q., Stewart, R., Stillman, M., Tuexen, M., and A. 177 Silverton, "Endpoint Handlespace Redundancy Protocol 178 (ENRP)", RFC 5353, September 2008. 180 [RFC5354] Stewart, R., Xie, Q., Stillman, M., and M. Tuexen, 181 "Aggregate Server Access Protocol (ASAP) and Endpoint 182 Handlespace Redundancy Protocol (ENRP) Parameters", 183 RFC 5354, September 2008. 185 [RFC5355] Stillman, M., Gopal, R., Guttman, E., Sengodan, S., and M. 186 Holdrege, "Threats Introduced by Reliable Server Pooling 187 (RSerPool) and Requirements for Security in Response to 188 Threats", RFC 5355, September 2008. 190 [RFC5356] Dreibholz, T. and M. Tuexen, "Reliable Server Pooling 191 Policies", RFC 5356, September 2008. 193 6.2. Informative References 195 [AINA2009] 196 Zhou, X., Dreibholz, T., Fa, F., Du, W., and E. Rathgeb, 197 "Evaluation and Optimization of the Registrar Redundancy 198 Handling in Reliable Server Pooling Systems", 199 Proceedings of the IEEE 23rd International Conference on 200 Advanced Information Networking and Applications (AINA 201 2009), May 2009. 203 [RSerPoolPage] 204 Dreibholz, T., "Thomas Dreibholz's RSerPool Page", 205 URL: http://tdrwww.iem.uni-due.de.de/dreibholz/rserpool/. 207 [Dre2006] Dreibholz, T., "Reliable Server Pooling -- Evaluation, 208 Optimization and Extension of a Novel IETF Architecture", 209 Ph.D. Thesis University of Duisburg-Essen, Faculty of 210 Economics, Institute for Computer Science and Business 211 Information Systems, URL: http:// 212 duepublico.uni-duisburg-essen.de/servlets/DerivateServlet/ 213 Derivate-16326/Dre2006-final.pdf, March 2007. 215 [IJHIT2008] 216 Dreibholz, T. and E. Rathgeb, "An Evalulation of the Pool 217 Maintenance Overhead in Reliable Server Pooling Systems", 218 International Journal of Hybrid Information Technology 219 (IJHIT) Volume 1, Number 2, April 2008. 221 [I-D.dreibholz-rserpool-asap-hropt] 222 Dreibholz, T., "Handle Resolution Option for ASAP", 223 draft-dreibholz-rserpool-asap-hropt-03 (work in progress), 224 October 2008. 226 [I-D.dreibholz-rserpool-delay] 227 Dreibholz, T. and X. Zhou, "Definition of a Delay 228 Measurement Infrastructure and Delay-Sensitive Least-Used 229 Policy for Reliable Server Pooling", 230 draft-dreibholz-rserpool-delay-02 (work in progress), 231 July 2008. 233 Authors' Addresses 235 Thomas Dreibholz 236 University of Duisburg-Essen, Institute for Experimental Mathematics 237 Ellernstrasse 29 238 45326 Essen, Nordrhein-Westfalen 239 Germany 241 Phone: +49-201-1837637 242 Fax: +49-201-1837673 243 Email: dreibh@iem.uni-due.de 244 URI: http://www.iem.uni-due.de/~dreibh/ 245 Xing Zhou 246 Hainan University, College of Information Science and Technology 247 Renmin Avenue 58 248 570228 Haikou, Hainan 249 China 251 Phone: +86-898-66279141 252 Email: zhouxing@hainu.edu.cn