On Line Markets for Distributed Object Services: The MAJIC System Lior Levy, Liad Blumrosen and Noam Nisan The Hebrew University, Jerusalem Presented by Liad Blumrosen

26th March 2001USITS '012 Outline Motivation A blueprint The MAJIC system Experimental Results Conclusions

26th March 2001USITS '013 Economic systems Many distributed resources on the Internet CPU Memory Hardware Data The resources belong to different organizations Resources owners must have motivation to share them with others This leads to economic systems –payments for services –E.g. Spawn, Popcorn, SuperWeb

26th March 2001USITS '014 Distributed objects paradigm Computers on a network encapsulate their sharable resources in well defined interfaces Other computers can use these resources by Remote Procedure Calls (RPC) –basis of CORBA, DCOM, JAVA RMI

26th March 2001USITS '015 We propose a general architecture for augmenting distributed-object systems with payments Combining the paradigms Distributed objects paradigms Economic paradigm Our architecture The architecture is easily inter-operable with the current leading technologies

26th March 2001USITS '016 Market Motivating Example: printer service A laptop is looking for a printer in a network Market.getPrinter()4$ 3$ 6$ Printer1.getPrice() Printer3.getPrice() Printer2.getPrice() Printer 2 3$

26th March 2001USITS '017 Motivating Example: printer service A laptop is looking for a printer in a network Printer 2 3$ Printer2.print( page ) Printer2.pay( 3$ )

26th March 2001USITS '018 Service parameters The printer service is an example of a Service Type –E.g. memory storage, database services, compression algorithms Each Service Type has a set of parameters defining its parameter space –For example: printing quality, printing speed, paper size, printer’s location A service provider can supply the service in a subset of this parameter space –“I can only print A4 or Letter page sizes”

26th March 2001USITS '019 Handling service parameters The problem: market fragmentation due to multi-parameter services –eliminating competition and flexibility The solution: work in a single market, and take parameters into account during resource assignment.

26th March 2001USITS '0110 Parameters specification Utility function –Buyer’s benefit from receiving a service at a certain point in the parameter space Parameters search engine –Input: a seller’s quote function (“catalog”) –Output: the desired point in the parameter space Service Users - “buyers” Quote function –Price for providing a service for each point in the parameter space –equivalent to a “catalog” Service providers - “sellers”

26th March 2001USITS '0111 The market mechanism The market place Players send functions encapsulated in objects ! Params search engine Utility function printer 1 printer 2 printer 3 Quote 1 Quote 2 Quote 3 params 1 params 2 params 3

26th March 2001USITS '0112 The market mechanism The market place printer 1 printer 2 printer 3 4$ 3$ 6$ utilities Quote 1 Quote 2 Quote 3 params 1 params 2 params 3 quotes 2$ 3$ 2$ Params search engine Utility function

26th March 2001USITS '0113 The market place The market mechanism printer 1 printer 2 printer 3 utilities 4$ 3$ 7$ Buyer’s surplus 4$ 1$ 2$ The printer that provides maximal surplus 2$ 3$ 2$ quotes Quote 1 Quote 2 Quote 3 params 1 params 2 params 3

26th March 2001USITS '0114 The market place The market mechanism printer 1 printer 2 printer 3 utilities 7$ Buyer’s surplus 4$ 3$ quotes Quote 1 params 1 Printing on printer 1 paying 3$ to printer 1

26th March 2001USITS '0115 Vickrey pricing Untruthful sellers lead to inefficient allocations We introduce the “2nd price auction for distributed objects” –generalizes Vickrey’s 2nd price auction Theorem: Our architecture is Incentive Compatible for sellers (I.e. sellers’ best strategy is to declare the truth) Proved using game theoretic notions from Mechanism Design and Auctions Theory

26th March 2001USITS '0116 Load balancing as a by product Completion time 1 sec Price per page 1$ 2$ The clients wants the printing to be completed ASAP Their utility decreases in 1$ with every second of delay. 2 sec 3 sec 2 sec According to a theorem and experimental results,the load balancing basically works

26th March 2001USITS '0117 The system is built on top of Sun’s JINI TM distributed system It implements the blueprint described earlier Built in the Hebrew University, Israel The MAJIC system Multiparameter Auctions for JIni Components Economic mechanismJINI Platform MAJIC System

26th March 2001USITS '0118 JINI TM Overview “The Lookup Service” request “Lookup”: Match a service that satisfies the request JINI Client Proxy 1 Proxy 2 Proxy 3 Proxy 2 JINI Services Method invocation “ Discovery & Join ” : Registration

26th March 2001USITS '0119 The MAJIC market The market is an extension of the Lookup service –uses economic mechanism to perform the Lookup protocol The seller is a JINI service provider –Upon registration, submits a quote object to the market The buyer is a JINI client –Submits a request, containing utility and parameter search engine objects

26th March 2001USITS '0120 The MAJIC system “The Lookup Service” Client Request Utility function Search engine Market assigns the seller that brings the best surplus to the buyer Proxy 1Quote 1 Proxy 2Quote 2 Proxy 3Quote 3 Proxy 2 Services Contract The market performs online auction as described earlier

26th March 2001USITS '0121 The MAJIC system “The Lookup Service” Client Proxy 2Quote 2 Proxy 2 Services The client invokes the service using its proxy The client pays according to the contract.

26th March 2001USITS '0122 Experimental Results System performance –Measured by the market response time to clients requests –About 15% average overhead per request in a high load scenario

26th March 2001USITS '0123 Experimental Results (cont.) Economic efficiency –Clients preferences affect the market assignments as expected –Example: Assignment of high quality printers to buyers that prefer it the most

26th March 2001USITS '0124 Experimental Results (cont.) Load balancing –Clients’ utility decreases as service’s load increases –Leads to a load- balancing effect.

26th March 2001USITS '0125 Conclusions We have introduced a blueprint for an infrastructure that performs on line auctions for distributed object services. Aspects that distinguish our work from previous systems: –A general-purpose architecture (not dedicated to a single resource). –Handling a multi-parameter space in a non trivial way.

26th March 2001USITS '0126 For more details, see the MAJIC homepage: