Network Working Group                                       T. Dreibholz
Internet-Draft                              University of Duisburg-Essen
Intended status: Experimental                            January 5, 2010
Expires: July 9, 2010


                   Handle Resolution Option for ASAP
               draft-dreibholz-rserpool-asap-hropt-06.txt

Abstract

   This document describes the Handle Resolution option for the ASAP
   protocol.

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   include Simplified BSD License text as described in Section 4.e of
   the Trust Legal Provisions and are provided without warranty as
   described in the BSD License.


Table of Contents

   1.  Introduction  . . . . . . . . . . . . . . . . . . . . . . . . . 3
     1.1.  Scope . . . . . . . . . . . . . . . . . . . . . . . . . . . 3
     1.2.  Terminology . . . . . . . . . . . . . . . . . . . . . . . . 3
     1.3.  Conventions . . . . . . . . . . . . . . . . . . . . . . . . 3
   2.  Handle Resolution Option  . . . . . . . . . . . . . . . . . . . 3
     2.1.  Definition  . . . . . . . . . . . . . . . . . . . . . . . . 3
   3.  Reference Implementation  . . . . . . . . . . . . . . . . . . . 4
   4.  Security Considerations . . . . . . . . . . . . . . . . . . . . 4
   5.  IANA Considerations . . . . . . . . . . . . . . . . . . . . . . 4
   6.  Acknowledgments . . . . . . . . . . . . . . . . . . . . . . . . 5
   7.  References  . . . . . . . . . . . . . . . . . . . . . . . . . . 5
     7.1.  Normative References  . . . . . . . . . . . . . . . . . . . 5
     7.2.  Informative References  . . . . . . . . . . . . . . . . . . 5
   Author's Address  . . . . . . . . . . . . . . . . . . . . . . . . . 6






























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1.  Introduction

   Reliable Server Pooling defines protocols for providing highly
   available services.  The Aggregate Server Access Protocol (ASAP)
   provides session management and server selection for applications.
   Upon request for a server selection -- denoted as handle resolution
   -- an ENRP server returns a list of selected PE identities.  The
   number of PE identities to be returned is not specified by RSerPool.
   Furthermore the ASAP protocol does not contain a way for letting the
   requesting instance specify it.

   As shown in [Dre2006], [IJHIT2008], selecting too many entries does
   not make sense for the application, but on the other hand also result
   in significant processing and network overhead.  Furthermore, it has
   been shown in [LCN2005] that the number of requested elements is
   usually 1, but there are application cases where more PE identities
   have to be returned.  That is, there should be a possibility to
   specify the number of requested PE items upon a handle resolution.

1.1.  Scope

   The Handle Resolution option defined in this draft simply defines an
   option to let the PU-side specify the desired number of PE identities
   from the ENRP server.

1.2.  Terminology

   The terms are commonly identified in related work and can be found in
   the Aggregate Server Access Protocol and Endpoint Handlespace
   Redundancy Protocol Common Parameters document RFC 5354 [RFC5354].

1.3.  Conventions

   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].


2.  Handle Resolution Option

2.1.  Definition

   The Handle Resolution MAY be used once in an ASAP Handle Resolution
   message sent from a PU to an ENRP server.  It is defined as follows.







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      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 = 0x803f         |            Length=8            |
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
      |                             Items                             |
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+

   Items: 32 bits (unsigned integer)

   Contains the number of PE identities to be selected by the ENRP
   server.  Setting it to 0xffffffff denotes to obtain as many PE
   identities as possible.  A setting of 0 denotes to use the ENRP
   server's default value; this default MUST be used if there is no
   Handle Resolution option given.  The ENRP server SHOULD try to fulfil
   the request for the given number of items.

   Note, that the high-order bits of the type field are set to 10, which
   means "skip this parameter and continue processing" if this parameter
   type is not supported by the ENRP server.  This allows for
   interoperability with old implementations.


3.  Reference Implementation

   The RSerPool reference implementation RSPLIB can be found at
   [RSerPoolPage].  It supports the functionalities defined by
   [RFC5351], [RFC5352], [RFC5353], [RFC5354] and [RFC5356] as well as
   the options [I-D.dreibholz-rserpool-delay],
   [I-D.dreibholz-rserpool-enrp-takeover] and of course the option
   defined by this document.  An introduction to this implementation is
   provided in [Dre2006].


4.  Security Considerations

   Security considerations for RSerPool systems are described by
   [RFC5355].


5.  IANA Considerations

   This document does not require additional IANA actions beyond those
   already identified in the ENRP and ASAP protocol specifications.







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6.  Acknowledgments

   The author would like to thank Nihad Cosic, Dirk Hoffstadt, Michael
   Kohnen, Jobin Pulinthanath and Xing Zhou for their support.


7.  References

7.1.  Normative References

   [RFC2119]  Bradner, S., "Key words for use in RFCs to Indicate
              Requirement Levels", BCP 14, RFC 2119, March 1997.

   [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",
              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.

7.2.  Informative References

   [RSerPoolPage]
              Dreibholz, T., "Thomas Dreibholz's RSerPool Page",
              URL: http://tdrwww.iem.uni-due.de.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



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              Information Systems, URL: http://
              duepublico.uni-duisburg-essen.de/servlets/DerivateServlet/
              Derivate-16326/Dre2006-final.pdf, March 2007.

   [LCN2005]  Dreibholz, T. and E. Rathgeb, "On the Performance of
              Reliable Server Pooling Systems", Proceedings of the 30th
              IEEE Local Computer Networks Conference, November 2005.

   [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.

   [I-D.dreibholz-rserpool-enrp-takeover]
              Dreibholz, T. and X. Zhou, "Takeover Suggestion Flag for
              the ENRP Handle Update Message",
              draft-dreibholz-rserpool-enrp-takeover-01 (work in
              progress), January 2009.

   [I-D.dreibholz-rserpool-delay]
              Dreibholz, T. and X. Zhou, "Definition of a Delay
              Measurement Infrastructure and Delay-Sensitive  Least-Used
              Policy for Reliable Server Pooling",
              draft-dreibholz-rserpool-delay-03 (work in progress),
              January 2009.


Author's Address

   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/











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