Simulation for Cache Mesh Design Lund, Tuesday 8 June 1999 TERENA-NORDUnet Networking Conference Nicolas Saillard

Why simulating Cache Meshes ? A need to design a caching architecture that works well A need to choose between a lot of different materials and configurations Difficulty in testing these different solutions on a real network, one solution is simulation.

A simulation environment (Application to sizing a cache mesh) Network Elements Client (random process: Zipf-like law) Server (Mean File Size = 13 KB) Cache (LRU stack) Measurements (Hit Rate) A cost-benefit function ( Hit Rate, Cache size)

A graphical and dynamic tool

How to size a single cache ?

How to size a Parent Cache ? Server Parameters : Child cache size Amount of unique data requested Parent cache Size Use of cooperation protocol (ICP) ? Parent Cache CB CA Child Caches Client A Client B

A cost-benefit analysis

Further work Simulator abilities ( CARP, cache-digest ) Latency measurments Cost-benefit functions ( material, human and bandwidth cost ) Take into account traffic increase Be able to define an optimal caching solution