Internet DRAFT - draft-dreibholz-rserpool-applic-distcomp
draft-dreibholz-rserpool-applic-distcomp
Network Working Group T. Dreibholz
Internet-Draft University of Duisburg-Essen
Intended status: Informational January 01, 2012
Expires: July 4, 2012
Applicability of Reliable Server Pooling for Real-Time Distributed
Computing
draft-dreibholz-rserpool-applic-distcomp-12.txt
Abstract
This document describes the applicability of the Reliable Server
Pooling architecture to manage real-time distributed computing pools
and access the resources of such pools.
Status of this Memo
This Internet-Draft is submitted in full conformance with the
provisions of BCP 78 and BCP 79.
Internet-Drafts are working documents of the Internet Engineering
Task Force (IETF). Note that other groups may also distribute
working documents as Internet-Drafts. The list of current Internet-
Drafts is at http://datatracker.ietf.org/drafts/current/.
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."
This Internet-Draft will expire on July 4, 2012.
Copyright Notice
Copyright (c) 2012 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
(http://trustee.ietf.org/license-info) in effect on the date of
publication of this document. Please review these documents
carefully, as they describe your rights and restrictions with respect
to this document. Code Components extracted from this document must
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 Simplified BSD License.
Dreibholz Expires July 4, 2012 [Page 1]
Internet-Draft RSerPool for Distributed Computing January 2012
This document may contain material from IETF Documents or IETF
Contributions published or made publicly available before November
10, 2008. The person(s) controlling the copyright in some of this
material may not have granted the IETF Trust the right to allow
modifications of such material outside the IETF Standards Process.
Without obtaining an adequate license from the person(s) controlling
the copyright in such materials, this document may not be modified
outside the IETF Standards Process, and derivative works of it may
not be created outside the IETF Standards Process, except to format
it for publication as an RFC or to translate it into languages other
than English.
Table of Contents
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . . 3
1.1. Scope . . . . . . . . . . . . . . . . . . . . . . . . . . . 3
1.2. Terminology . . . . . . . . . . . . . . . . . . . . . . . . 3
2. Distributed Computing using RSerPool . . . . . . . . . . . . . 3
2.1. Requirements . . . . . . . . . . . . . . . . . . . . . . . 3
2.2. Architecture . . . . . . . . . . . . . . . . . . . . . . . 4
2.3. Limitations . . . . . . . . . . . . . . . . . . . . . . . . 5
3. Reference Implementation . . . . . . . . . . . . . . . . . . . 5
4. Security Considerations . . . . . . . . . . . . . . . . . . . . 5
5. IANA Considerations . . . . . . . . . . . . . . . . . . . . . . 6
6. References . . . . . . . . . . . . . . . . . . . . . . . . . . 6
6.1. Normative References . . . . . . . . . . . . . . . . . . . 6
6.2. Informative References . . . . . . . . . . . . . . . . . . 7
Author's Address . . . . . . . . . . . . . . . . . . . . . . . . . 8
Dreibholz Expires July 4, 2012 [Page 2]
Internet-Draft RSerPool for Distributed Computing January 2012
1. Introduction
Reliable Server Pooling defines protocols for providing highly
available services. The services are located in a pool of redundant
servers and if a server fails, another server will take over. The
only requirement put on these servers belonging to the pool is that
if state is maintained by the server, this state must be transferred
to the other server taking over.
The goal is to provide server-based redundancy. Transport and
network level redundancy are handled by the transport and network
layer protocols.
The application may choose to distribute its traffic over the servers
of the pool conforming to a certain policy.
1.1. Scope
The scope of this document is to explain the way of using Reliable
Server Pooling mechanisms to manage and access pools of Distributed
Computing resources.
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 [RFC5354].
2. Distributed Computing using RSerPool
2.1. Requirements
The application scenario for Distributed Computing is defined as
follows:
o Clients generate large computation jobs. Jobs have to be
processed by servers as soon as possible (real-time), i.e. unlike
concepts like SETI@home [SETIatHome], it is not possible to let
clients fetch a job, process it later and may be some day upload
the result.
o Jobs may be partitionable, i.e. they can be split up to smaller
pieces which can be processed independently and the processing
results can be concatenated to the processing result of the
complete job. Jobs have to be processed by servers.
Dreibholz Expires July 4, 2012 [Page 3]
Internet-Draft RSerPool for Distributed Computing January 2012
o Servers may be unreliable; i.e. user computers may be temporarily
added to the pool of computing resources and may be revoked when
they are used again by their owners. Furthermore, they may simply
disappear because of broken network connections (modems, etc.) or
power turned off.
o The processing power of servers in a pool of computing resources
may be very heterogeneous, i.e. a few supercomputers and many low-
end user PCs.
Maintaining a Distributed Computing pool for the scenario described
above arises the following requirements to the pool management:
o It must be possible to manage large server pools, e.g. up to some
hundreds or even thousands of servers.
o Due to heterogeneous processing resources within a pool, it must
be possible to use appropriate server selection procedures to
meaningfully utilize the available resources.
o It must be possible to dynamically add and remove servers.
o Servers may be unreliable, especially when the servers are
represented by user PCs. Failover mechanisms are required to
continue an interrupted computation session.
2.2. Architecture
All requirements for pool and session management of the Distributed
Computing scenario defined in the previous section can be fulfilled
by the Reliable Server Pooling architecture:
o An efficient implementation of the handlespace management
structures allows pools to contain thousands of elements.
Handlespace management structures have been proposed, implemented
and analyzed in [IJHIT2008], [Dre2006].
o RSerPool allows to specify server selection rules by pool member
selection policies [RFC5356]. A set of adaptive and non-adaptive
policies is already defined. To fulfill the requirements of new
applications, it is also possible to define new policies.
Research has already been made on the subject of load distribution
efficiency of pool policies in Distributed Computing scenarios:
see [Dre2006], [IJAIT2009], [LCN2005], [Tencon2005],
[Euromicro2007] for details.
o Dynamic addition and removal of PEs is a feature of RSerPool
[RFC5352].
Dreibholz Expires July 4, 2012 [Page 4]
Internet-Draft RSerPool for Distributed Computing January 2012
o The control/data channel concept [RFC5351] of RSerPool realizes a
session layer. That is, RSerPool already handles the main task of
maintaining and monitoring connections between PUs and PEs; the
only task of the application layer to provide full failover
functionality is to realize an application-dependent failover
procedure. By the usage of client-based state synchronization
[IJAIT2009], [LCN2002] in the form of ASAP Cookies, a failover may
be fully transparent to the PU while only a state restoration is
necessary on the PE side. A demo application [RSerPoolPage] using
the RSerPool session layer in a Distributed Computing application
is described in [Infocom2005].
2.3. Limitations
Applying RSerPool for distributed computing applications, the duties
of the RSerPool architecture are still limited to the management of
pools and independent sessions only. It is in particular a non-goal
to provide functionalities like data synchronization among sessions,
user authentication, accounting or the support for more than one
administrative domain. Such functionalities are considered to be
application-specific and are therefore out of the scope of RSerPool.
3. Reference Implementation
The RSerPool reference implementation RSPLIB, including example
Distributed Computing applications, can be found at [RSerPoolPage].
It supports the functionalities defined by [RFC5351], [RFC5352],
[RFC5353], [RFC5354] and [RFC5355] as well as the options
[I-D.dreibholz-rserpool-asap-hropt],
[I-D.dreibholz-rserpool-enrp-takeover] and
[I-D.dreibholz-rserpool-delay]. An introduction to this
implementation is provided in [Dre2006].
4. Security Considerations
The protocols used in the Reliable Server Pooling architecture only
try to increase the availability of the servers in the network.
RSerPool protocols do not contain any protocol mechanisms which are
directly related to user message authentication, integrity and
confidentiality functions. For such features, it depends on the
IPSEC protocols or on Transport Layer Security (TLS) protocols for
its own security and on the architecture and/or security features of
its user protocols.
The RSerPool architecture allows the use of different transport
protocols for its application and control data exchange. These
Dreibholz Expires July 4, 2012 [Page 5]
Internet-Draft RSerPool for Distributed Computing January 2012
transport protocols may have mechanisms for reducing the risk of
blind denial-of-service attacks and/or masquerade attacks. If such
measures are required by the applications, then it is advised to
check the SCTP (see [RFC4960]) applicability statement [RFC3257] for
guidance on this issue.
5. IANA Considerations
This document introduces no additional considerations for IANA.
6. References
6.1. Normative References
[RFC3257] Coene, L., "Stream Control Transmission Protocol
Applicability Statement", RFC 3257, April 2002.
[RFC4960] Stewart, R., "Stream Control Transmission Protocol",
RFC 4960, September 2007.
[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.
[I-D.dreibholz-rserpool-asap-hropt]
Dreibholz Expires July 4, 2012 [Page 6]
Internet-Draft RSerPool for Distributed Computing January 2012
Dreibholz, T., "Handle Resolution Option for ASAP",
draft-dreibholz-rserpool-asap-hropt-09 (work in progress),
July 2011.
[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-08 (work in progress),
July 2011.
[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-06 (work in
progress), July 2011.
6.2. Informative References
[Dre2006] Dreibholz, T., "Reliable Server Pooling - Evaluation,
Optimization and Extension of a Novel IETF Architecture",
March 2007.
[Euromicro2007]
Dreibholz, T., Zhou, X., and E. Rathgeb, "A Performance
Evaluation of RSerPool Server Selection Policies in
Varying Heterogeneous Capacity Scenarios", Proceedings of
the 33rd IEEE EuroMirco Conference on Software Engineering
and Advanced Applications, Pages 157-164, ISBN 0-7695-
2977-1, DOI 10.1109/EUROMICRO.2007.9, August 2007.
[IJAIT2009]
Dreibholz, T. and E. Rathgeb, "Overview and Evaluation of
the Server Redundancy and Session Failover Mechanisms in
the Reliable Server Pooling Framework", International
Journal on Advances in Internet Technology (IJAIT), Volume
2, Number 1, Pages 1-14, ISSN 1942-2652, June 2009.
[IJHIT2008]
Dreibholz, T. and E. Rathgeb, "An Evaluation of the Pool
Maintenance Overhead in Reliable Server Pooling Systems",
SERSC International Journal on Hybrid Information
Technology (IJHIT), Volume 1, Number 2, Pages 17-32,
ISSN 1738-9968, April 2008.
[Infocom2005]
Dreibholz, T. and E. Rathgeb, "An Application
Demonstration of the Reliable Server Pooling Framework",
Dreibholz Expires July 4, 2012 [Page 7]
Internet-Draft RSerPool for Distributed Computing January 2012
Proceedings of the 24th IEEE INFOCOM , March 2005.
[LCN2002] Dreibholz, T., "An Efficient Approach for State Sharing in
Server Pools", Proceedings of the 27th IEEE Local Computer
Networks Conference (LCN), Pages 348-349, ISBN 0-7695-
1591-6, DOI 10.1109/LCN.2002.1181806, November 2002.
[LCN2005] Dreibholz, T. and E. Rathgeb, "On the Performance of
Reliable Server Pooling Systems", Proceedings of the IEEE
Conference on Local Computer Networks (LCN) 30th
Anniversary, Pages 200-208, ISBN 0-7695-2421-4,
DOI 10.1109/LCN.2005.98, November 2005.
[RSerPoolPage]
Dreibholz, T., "Thomas Dreibholz's RSerPool Page", 2011.
[SETIatHome]
SETI Project, "SETI@home: Search for Extraterrestrial
Intelligence at home", 2010.
[Tencon2005]
Dreibholz, T. and E. Rathgeb, "The Performance of Reliable
Server Pooling Systems in Different Server Capacity
Scenarios", Proceedings of the IEEE TENCON, ISBN 0-7803-
9312-0, DOI 10.1109/TENCON.2005.300939, November 2005.
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/
Dreibholz Expires July 4, 2012 [Page 8]
