Network Working Group T. Dreibholz Internet-Draft University of Duisburg-Essen Intended status: Experimental X. Zhou Expires: June 16, 2009 Hainan University December 13, 2008 Takeover Suggestion Flag for the ENRP Handle Update Message draft-dreibholz-rserpool-enrp-takeover-00.txt Status of this Memo By submitting this Internet-Draft, each author represents that any applicable patent or other IPR claims of which he or she is aware have been or will be disclosed, and any of which he or she becomes aware will be disclosed, in accordance with Section 6 of 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 June 16, 2009. Abstract This document describes the Takeover Suggestion Flag for the ENRP_HANDLE_UPDATE message of the ENRP protocol. Dreibholz & Zhou Expires June 16, 2009 [Page 1]
Internet-Draft Takeover Suggestion Flag December 2008 Table of Contents 1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . . 3 1.1. Scope . . . . . . . . . . . . . . . . . . . . . . . . . . . 3 1.2. Terminology . . . . . . . . . . . . . . . . . . . . . . . . 3 2. Takeover Suggestion Flag . . . . . . . . . . . . . . . . . . . 3 2.1. Definition . . . . . . . . . . . . . . . . . . . . . . . . 3 2.2. Reference Implementation . . . . . . . . . . . . . . . . . 4 3. References . . . . . . . . . . . . . . . . . . . . . . . . . . 4 3.1. Normative References . . . . . . . . . . . . . . . . . . . 4 3.2. Informative References . . . . . . . . . . . . . . . . . . 5 Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . . 5 Intellectual Property and Copyright Statements . . . . . . . . . . 7 Dreibholz & Zhou Expires June 16, 2009 [Page 2]
Internet-Draft Takeover Suggestion Flag December 2008 1. Introduction Reliable Server Pooling as described in [RFC5351] defines protocols for providing highly available services. The management component used for pool administration is denoted as ENRP Server or Pool Registrar (PR). Since a single ENRP server constitutes a single point of failure, there must be multiple ENRP servers. Servers, denoted as Pool Elements (PE), use an arbitrary ENRP server for registration into the pool. The chosen ENRP server becomes the Home ENRP Server, also denoted as Home PR (PR-H), of the PE. It is responsible for making the PE identity known to the other ENRP servers (by using ENRP_HANDLE_UPDATE messages) and also to monitor the PE health (by using keep-alive messages). As shown in [AINA2009], the following scenario leads to unbalanced ENRP server workload: consider a set of multiple ENRP servers with one subset being unreliable (for example, their network connection has problems) and some reliable ENRP servers. After a while, the reliable ENRP server will get the home ENRP server role for almost all of the PEs, which results in high workload for this ENRP server. Since the home ENRP server role is more computation-intensive (as shown by [IJHIT2008]), this leads to highly unbalanced workload for large RSerPool setups. This unbalanced workload remains, even when the unreliable ENRP servers become reliable again (for example, when the network problems have been solved). 1.1. Scope The Takeover Suggestion Flag defined in this draft defines a flag for the ENRP_HANDLE_UPDATE message. If the flag is set, the receiving ENRP server is suggested to take over the PE specified in the ENRP_HANDLE_UPDATE message. 1.2. Terminology The terms are commonly identified in related work and can be found in the RSerPool Overview document RFC 5351 [RFC5351]. 2. Takeover Suggestion Flag 2.1. Definition In this subsection, only the differences to the ENRP_HANDLE_UPDATE message defined in [RFC5353] are explained. The following figure shows the ENRP_HANDLE_UPDATE message: Dreibholz & Zhou Expires June 16, 2009 [Page 3]
Internet-Draft Takeover Suggestion Flag December 2008 0 1 2 3 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 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Type = 0x04 |0|0|0|0|0|0|0|T| Message Length | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Sending Server's ID | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Receiving Server's ID | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Update Action | (reserved) | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ : Pool Handle Parameter : +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ : Pool Element Parameter : +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ T flag: 1 bit (boolean) If set, the receiving ENRP server is suggested to take over the PE specified by the Pool Handle and Pool Element Parameters. It is RECOMMENDED for the receiving ENRP server to perform this takeover if it has the resources to do so. 2.2. Reference Implementation The reference implementation based on the RSerPool implementation RSPLIB can be found at [RSerPoolPage]. 3. References 3.1. Normative References [RFC5351] Lei, P., Ong, L., Tuexen, M., and T. Dreibholz, "An Overview of Reliable Server Pooling Protocols", RFC 5351, September 2008. [RFC5352] Stewart, R., Xie, Q., Stillman, M., and M. Tuexen, "Aggregate Server Access Protocol (ASAP)", RFC 5352, September 2008. [RFC5353] Xie, Q., Stewart, R., Stillman, M., Tuexen, M., and A. Silverton, "Endpoint Handlespace Redundancy Protocol (ENRP)", RFC 5353, September 2008. [RFC5354] Stewart, R., Xie, Q., Stillman, M., and M. Tuexen, "Aggregate Server Access Protocol (ASAP) and Endpoint Handlespace Redundancy Protocol (ENRP) Parameters", Dreibholz & Zhou Expires June 16, 2009 [Page 4]
Internet-Draft Takeover Suggestion Flag December 2008 RFC 5354, September 2008. [RFC5355] Stillman, M., Gopal, R., Guttman, E., Sengodan, S., and M. Holdrege, "Threats Introduced by Reliable Server Pooling (RSerPool) and Requirements for Security in Response to Threats", RFC 5355, September 2008. [RFC5356] Dreibholz, T. and M. Tuexen, "Reliable Server Pooling Policies", RFC 5356, September 2008. 3.2. Informative References [AINA2009] Dreibholz, T., Zhou, X., Du, W., and E. Rathgeb, "Evaluation and Optimization of the Registrar Redundancy Handling in Reliable Server Pooling Systems", Proceedings of the IEEE 23rd International Conference on Advanced Information Networking and Applications (AINA 2009), May 2009. [RSerPoolPage] Dreibholz, T., "Thomas Dreibholz's RSerPool Page", URL: http://tdrwww.exp-math.uni-essen.de/dreibholz/rserpool/. [Dre2006] Dreibholz, T., "Reliable Server Pooling -- Evaluation, Optimization and Extension of a Novel IETF Architecture", Ph.D. Thesis University of Duisburg-Essen, Faculty of Economics, Institute for Computer Science and Business Information Systems, URL: http:// duepublico.uni-duisburg-essen.de/servlets/DerivateServlet/ Derivate-16326/Dre2006-final.pdf, March 2007. [IJHIT2008] Dreibholz, T. and E. Rathgeb, "An Evalulation of the Pool Maintenance Overhead in Reliable Server Pooling Systems", International Journal of Hybrid Information Technology (IJHIT) Volume 1, Number 2, April 2008. Dreibholz & Zhou Expires June 16, 2009 [Page 5]
Internet-Draft Takeover Suggestion Flag December 2008 Authors' Addresses Thomas Dreibholz University of Duisburg-Essen, Institute for Experimental Mathematics Ellernstrasse 29 45326 Essen, Nordrhein-Westfalen Germany Phone: +49-201-1837637 Fax: +49-201-1837673 Email: dreibh@iem.uni-due.de URI: http://www.iem.uni-due.de/~dreibh/ Xing Zhou Hainan University, College of Information Science and Technology Renmin Avenue 58 570228 Haikou, Hainan China Phone: +86-898-66279141 Email: zhouxing@hainu.edu.cn Dreibholz & Zhou Expires June 16, 2009 [Page 6]
Internet-Draft Takeover Suggestion Flag December 2008 Full Copyright Statement Copyright (C) The IETF Trust (2008). This document is subject to the rights, licenses and restrictions contained in BCP 78, and except as set forth therein, the authors retain all their rights. This document and the information contained herein are provided on an "AS IS" basis and THE CONTRIBUTOR, THE ORGANIZATION HE/SHE REPRESENTS OR IS SPONSORED BY (IF ANY), THE INTERNET SOCIETY, THE IETF TRUST AND THE INTERNET ENGINEERING TASK FORCE DISCLAIM ALL WARRANTIES, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO ANY WARRANTY THAT THE USE OF THE INFORMATION HEREIN WILL NOT INFRINGE ANY RIGHTS OR ANY IMPLIED WARRANTIES OF MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE. Intellectual Property The IETF takes no position regarding the validity or scope of any Intellectual Property Rights or other rights that might be claimed to pertain to the implementation or use of the technology described in this document or the extent to which any license under such rights might or might not be available; nor does it represent that it has made any independent effort to identify any such rights. Information on the procedures with respect to rights in RFC documents can be found in BCP 78 and BCP 79. Copies of IPR disclosures made to the IETF Secretariat and any assurances of licenses to be made available, or the result of an attempt made to obtain a general license or permission for the use of such proprietary rights by implementers or users of this specification can be obtained from the IETF on-line IPR repository at http://www.ietf.org/ipr. The IETF invites any interested party to bring to its attention any copyrights, patents or patent applications, or other proprietary rights that may cover technology that may be required to implement this standard. Please address the information to the IETF at ietf-ipr@ietf.org. Dreibholz & Zhou Expires June 16, 2009 [Page 7]