Reliable Server Pooling Policies
RFC 5356

Network Working Group                                       T. Dreibholz
Request for Comments: 5356                  University of Duisburg-Essen
Category: Experimental                                         M. Tuexen
                                      Muenster Univ. of Applied Sciences
                                                          September 2008

                    Reliable Server Pooling Policies

Status of This Memo

   This memo defines an Experimental Protocol for the Internet
   community.  It does not specify an Internet standard of any kind.
   Discussion and suggestions for improvement are requested.
   Distribution of this memo is unlimited.

Abstract

   This document describes server pool policies for Reliable Server
   Pooling (RSerPool) including considerations for implementing them at
   Endpoint Handlespace Redundancy Protocol (ENRP) servers and pool
   users.

Table of Contents

   1. Introduction ....................................................3
   2. Conventions .....................................................3
   3. Terminology and Definitions .....................................3
      3.1. Load .......................................................3
      3.2. Weight .....................................................3
   4. Non-Adaptive Policies ...........................................4
      4.1. Round Robin Policy .........................................4
           4.1.1. Description .........................................4
           4.1.2. ENRP Server Considerations ..........................4
           4.1.3. Pool User Considerations ............................4
           4.1.4. Pool Member Selection Policy Parameter ..............4
      4.2. Weighted Round Robin Policy ................................5
           4.2.1. Description .........................................5
           4.2.2. ENRP Server Considerations ..........................5
           4.2.3. Pool User Considerations ............................5
           4.2.4. Pool Member Selection Policy Parameter ..............5
      4.3. Random Policy ..............................................5
           4.3.1. Description .........................................5
           4.3.2. ENRP Server Considerations ..........................6
           4.3.3. Pool User Considerations ............................6
           4.3.4. Pool Member Selection Policy Parameter ..............6
      4.4. Weighted Random Policy .....................................6
           4.4.1. Description .........................................6

Dreibholz & Tuexen            Experimental                      [Page 1]
RFC 5356                   RSerPool Policies              September 2008

           4.4.2. ENRP Server Considerations ..........................6
           4.4.3. Pool User Considerations ............................6
           4.4.4. Pool Member Selection Policy Parameter ..............7
      4.5. Priority Policy ............................................7
           4.5.1. Description .........................................7
           4.5.2. ENRP Server Considerations ..........................7
           4.5.3. Pool Element Considerations .........................7
           4.5.4. Pool Member Selection Policy Parameter ..............7
   5. Adaptive Policies ...............................................8
      5.1. Least Used Policy ..........................................8
           5.1.1. Description .........................................8
           5.1.2. ENRP Server Considerations ..........................8
           5.1.3. Pool User Considerations ............................8
           5.1.4. Pool Member Selection Policy Parameter ..............8
      5.2. Least Used with Degradation Policy .........................9
           5.2.1. Description .........................................9
           5.2.2. ENRP Server Considerations ..........................9
           5.2.3. Pool User Considerations ............................9
           5.2.4. Pool Member Selection Policy Parameter ..............9
      5.3. Priority Least Used Policy ................................10
           5.3.1. Description ........................................10
           5.3.2. ENRP Server Considerations .........................10
           5.3.3. Pool User Considerations ...........................10
           5.3.4. Pool Member Selection Policy Parameter .............10
      5.4. Randomized Least Used Policy ..............................11
           5.4.1. Description ........................................11
           5.4.2. ENRP Server Considerations .........................11
           5.4.3. Pool User Considerations ...........................11
           5.4.4. Pool Member Selection Policy Parameter .............11