Last Modifield: 05/06/2002
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 RSPool Requirements And Architecture document|
|Done||Submit Reqts draft to IESG for consideration as an Informational RFC|
|Done||Initial draft of Binding Service document|
|Done||Initial draft of Client/server binding and Server Pool Management document|
|NOV 01||Submit Architecture draft to IESG for consideration as an Informational RFC|
|JAN 02||Submit drafts of Binding Service and Server Pool Management to IESG for consideration as Proposed Standard RFCs|
|RFC3237||I||Requirements for Reliable Server Pooling|
Reliable Server Pooling WG (rserpool) Monday, November 18 at 1530-1730 ================================= co-CHAIRs: Maureen Stillman <Maureen.Stillman@nokia.com> Lyndon Ong <firstname.lastname@example.org> Approximately 30 people attended this meeting. We discussed the services document draft-conrad-rserpool-service-02. This describes the different services that rserpool can offer to the application. There are currently eight services defined and some new services being worked on. It has been updated to allow TCP or SCTP for PU communication with the ENRP server and any transport protocol for the application i.e. PU-PE transport. Service descriptions may need to be further refined on the mailing list. The services document was accepted as a Rserpool WG item. We discussed the TCP mapping document draft-conrad-rserpool-tcpmapping-01. The TCP mapping is a shim layer that provides an SCTP-like encapsulation/framing header. The TCP mapping document was accepted as a Rserpool WG item. We discussed the Rserpool architecture draft-ietf-rserpool-arch-03.txt. Control channel and data channel need to be clearly defined in terms of what messages are sent on each channel associated with each service. Further discussion will continue on the list. We discussed issues concerning business cards and state sharing information in connection with ASAP. Work on the protocol is ongoing. We discussed issues concerning multicast and security in ENRP. Three alternatives can be considered -- use multicast at your own risk, make multicast secure or abandon multicast. Also, we need to investigate a mixed network multicast and unicast. Further discussion will follow on the mailing list. The security threat document draft-stillman-rserpool-threats-02 has been on hold for the last six months while Rserpool experienced several significant protocol changes. We need to reexamine the document in light of recent changes to see if any updates are required. Also, we need to revisit the security architecture for Rserpool. This task will be performed by the Rserpool security design team. The security threat document was accepted as a Rserpool WG item. We had a discussion with the members of the IPFix (IP Flow Information Export) WG concerning their possible use of Reliable Server Pooling. They are working on a standard to export router flow information in a standard way. The exporter sends information to one or more collectors. It is these collectors that could form a reliable server pool. We investigated the possibility of adding a new service to Reliable Server Pooling in order to meet their requirements. Further discussions will follow.