Last Modified: 2003-01-21
The WG will define architecture and requirements for management and access to server pools, including requirements from a variety of applications, building blocks and interfaces, different styles of pooling, security requirements and performance requirements, such as failover times and coping with heterogeneous latencies. This will be documented in an Informational RFC.
The working group will focus on supporting high availability and scalability of applications through the use of pools of servers. This requires both a way to keep track of what servers are in the pool and are able to receive requests and a way for the client to bind to a desired server.
The Working Group will NOT address:
1) reliable multicast protocols - the use of multicast for reliable server pooling is optional. Reliable multicast protocols will be developed by the RMT WG.
2) synchronization/consistency of data between server pool elements, e.g. shared memory
3) mechanisms for sharing state information between server pool elements
4) Transaction failover. If a server fails during processing of a transaction this transaction may be lost. Some services may provide a way to handle the failure, but this is not guaranteed.
The WG will address client access mechanisms for server pools, specifically:
1) An access mechanism that allows geographically dispersed servers in the pool
2) A client-server binding mechanism that allows dynamic assignment of client to servers based on load balancing or application specific assignment policies.
3) Support of automatic reconfiguration of the client/server binding in case of server failure or administrative changes.
To the extent that new protocols are necessary to support the requirements for server pooling, these will be documented in a Standards Track RFC on client access to a binding service (i.e. name space) protocol.
The WG will also address use of proxying to interwork existing client access mechanisms to any new binding service.
The WG will address server pool management and a distributed service to support client/server binding, including:
1) A scalable mechanism for tracking server pool membership (incl. registration)
2) A scalable protocol for performing node failure detection, reconfiguration and failover, and otherwise managing the server pool (supporting caching, membership, query, authentication, and security)
3) A distributed service to support binding of clients to servers, based on information specific to the server pool. Given that this service is essential to access the server pool, a high degree of availability is necessary.
4) A means for allowing flexible load assignment and balancing policies
The protocols and procedures for server pool management will be documented in a Standards Track RFC.
The WG will address:
- transport protocol(s) that would be supported (eg. UDP, SCTP, TCP)
- any new congestion management issues
- relationship to existing work such as URI resolution mechanisms
Rserpool will consult with other IETF working groups such as Reliable multicast, DNS extensions, AAA, URN, WREC and Sigtran as appropriate and will not duplicate any of these efforts.
|Done||Initial draft of Protocol Comparison|
|Done||Initial draft of Threat Analysis|
|Done||Initial draft of MIB|
|Done||Initial draft of Rserpool Services document|
|Done||Initial draft of Pool Management document|
|Done||Initial draft of Rserpool Architecture document|
|Done||Initial draft of Binding Service document|
|Done||Submit Requirements document to IESG for Informational RFC|
|Done||Submit Comparison document to IESG for Informational RFC|
|Done||Initial draft of Resrpool Requirements document|
|Done||Initial draft of TCP Mapping document|
|NOV 02||Initial draft of Applicability Statement|
|MAR 03||Submit Architecture draft to IESG for Informational RFC|
|MAR 03||Submit Services document to IESG for Informational RFC|
|MAY 03||Submit TCP mapping to IESG for Proposed Standard RFC|
|MAY 03||Submit Threat Analysis to IESG for Informational RFC|
|AUG 03||Submit Binding Service and Pool Management to IESG for Proposed Standard RFC|
|AUG 03||Submit Applicability Statement to IESG for Informational RFC|
|NOV 03||Submit MIB to IESG for Proposed Standard RFC|
|RFC3237||I||Requirements for Reliable Server Pooling|
IETF #56 Reliable Server Pooling WG (rserpool) Monday, March 17, 2003 15:30-17:30 CHAIRs: Lyndon Ong <email@example.com> Maureen Stillman <Maureen.Stillman@nokia.com> Approximately 35 people attend the meeting. We discussed the services document draft-conrad-rserpool-service-03.txt. This draft describes the different services that rserpool can offer to the application. Recent discussions have resulted in some changes. An updated draft will be released shortly after IETF #56. The WG was asked to carefully review this document for any services that need to be added or changed. Service descriptions may need to be further refined on the mailing list. Outstanding issues with the tcpmapping document draft-conrad-rserpool-tcpmapping-01.txt were presented. Under discussion was the initial TSN (0 explicitly?) and message retrieval. Due to some changes agreed to in the services document, a better alignment with services draft will be included in the next draft. We discussed an open issue in the ASAP protocol draft-ietf-rserpool-asap-06.txt, specifically the configuration of the control and data channels. The concern is that if we allow different transport protocols for the control and data channels, the result is too complex. The consensus was to require data and control to use the same transport protocol and in addition, to use of separate pools for different protocols. Otherwise registration is complex and we prefer to keep it simple. Recent changes and issues concerning ENRP protocol draft-ietf-rserpool-enrp-04.txt were raised. We have added a Server_Announce message to allow name servers to broadcast so that PU or PE can find the home server. There was a question on the traffic impacts on wireless devices as it may create too much traffic. A possible solution is to limit multicast to wire, unicast over the air. The heartbeat mechanism must not be multicast, as multicast is not transparently supported across domains. Discussion of this issue will continue on the mailing list. The security design team has meet and discussed the security sections in both ASAP and ENRP. In addition, the design team reviewed the threat document, draft-ietf-rserpool-threats-00.txt. The open issue discussed is a requirement to ensure that if security is requested between the PU and ENRP server, then the PU is guaranteed not only to talk to an authenticated ENRP server, but also is guaranteed integrity and authentication of the PE registration data. These threats are documented in the threat document. Secondly, securing the control channel is an open issue. Given the consensus to require data and control channel to use the same transport solutions to the problem will be simpler. This will be further discussed on the list. The design team will continue working and report its findings to the list. The chair reopened the membership to any interested person. The applicability statement draft-coene-rserpool-applic-01.txt presents several examples or models of how Rserpool could be deployed. The group discussed that it needs to be aligned or merged with services document. The minimalist model was based on an IPFIX WG request. We discussed three current implementations of Rserpool from Siemens/University of Essen, Motorola and Temple University. Siemens/Essen: Linux, FreeBSD, DarwinOS For more information about this implementation, see: http://tdrwww.exp-math.uni-essen.de/dreibholz/rserpool/ and http://www.sctp.de/rserpool.html. An introduction to design and implementation of our rsplib prototype is given in the paper at: http://tdrwww.exp-math.uni-essen.de/drei bholz/rserpool/#Research. Motorola has an internal implementation; uses open source SCTP from sctp.org; Linux/Solaris> Temple has Kame SCTP; planning stages; FreeBSD. At this time the documents are becoming more stable with the exception of resolving security issues. The security design team will continue to meet with the expectation of resolving the above issues by IETF #57.