Virtual Organizations Virtual Organizations in the Arigatoni Overlay in the Arigatoni Overlay

NetworkNetwork

Luigi LiquoriLuigi LiquoriINRIA, FranceINRIA, France

Luigi.Liquori@inria.fr

Raphael ChandRaphael ChandINRIA, FranceINRIA, France

Raphael.Chand@inria.fr

Michel CosnardMichel CosnardINRIA, France INRIA, France

Michel.Cosnard@inria.fr

Virtual Organizations in the Arigatoni Overlay Network — L. Liquori et al. 2

Talk OutlineTalk Outline

Context and Arigatoni Model

Arigatoni’s Intermittence Rewriting Semantics

(a bit of) Arigatoni’s Resource Discovery

Arigatoni’s Protocol Evaluation

Conclusion and what’s next

Virtual Organizations in the Arigatoni Overlay Network — L. Liquori et al. 3

Context: Global ComputingContext: Global Computing Global Computing Communication Paradigm:

computation via a seamless, geographically distributed, open-ended network of bounded resources owned by ”Individuals”

Examples Internet (IP graph, a.k.a. “the backbone”, sharing) Telephone Network (Overlay with QoS) GRID (computing power sharing) P2P (data sharing) VoIP (band sharing) Web services (“semantic infos” sharing)

Virtual Organizations in the Arigatoni Overlay Network — L. Liquori et al. 4

Context: Overlay NetworksContext: Overlay Networks Challenges

Virtual Organizations of Individuals Resource Discovery between Individuals (of course … Security, Scalability, Reliability, and tutti frutti …)

Virtual Organization (Colony) How individuals organize themselves to share resources

transparently How the organization evolves in time and in space transparently

Resource Discovery How single resources, offered by individuals, are discovered How changed states of resources are upgrated in routing tables

… The Arigaroni Overlay Network (©INRIA)

Virtual Organizations in the Arigatoni Overlay Network — L. Liquori et al. 5

Global Computers, Brokers, Routers Global Computers, Brokers, Routers Global Computers (GCU)

Device of any size (GSM, PDA, Laptop, …, Cluster of PCs, …) Discontinuous participation in the Virtual Organization (Colony) Partial/Zero knowledge of the current Virtual Organization Ask and provide services with variable guarantees Can work in Local Mode or in Global Mode Motto: Global Mode … ask to the Colony boss, and wait for the best

…if the Colony boss ask for something do your best … Global Brokers (GBU)

Colony’s leader, but just individual in a surrounding “SuperColony” Register/Unregister GCU in the own colony Send/Receive GCU’s queries Contact GCUs in its population or contact its direct SuperGBs Trust their population at any level of the negotiation (via e.g. PKI)

Global Routers (GRU) Send/Receive Packets via a protocol (GIP) between GCU and GBU

Virtual Organizations in the Arigatoni Overlay Network — L. Liquori et al. 6

Arigatoni Overlay Network TopologyArigatoni Overlay Network Topology Arigatoni, Overlay Network composed by Colonies and SubColonies Global Brokers (GBU) = Routing queries (un/register, resource discovery) Global Computers (GCU) = Ask/provides resources interchangeably Global Router (GRU) = Dispatch packets around the network Hierarchical tree structured organization Once the resource/s is/are negotiated, GCUs

communicate in P2P fashion

GB

GB1GBn… GCkGC1

…

Leader

Individuals

Colony

GB

Leader

Leader Leader

GCkGC1…GCkGC1

…

SubColonySubColony

… …

Virtual Organizations in the Arigatoni Overlay Network — L. Liquori et al. 7

Syntax: Colonies and CommunitiesSyntax: Colonies and Communities

Colony syntax

Community (Soup) syntax

Virtual Organizations in the Arigatoni Overlay Network — L. Liquori et al. 8

Syntax ExamplesSyntax Examples

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Cardelli and Gordon Ambients …Cardelli and Gordon Ambients … “In the early days of the Internet one

could rely on a flat name space given by IP addresses; knowing the IP address of a computer would very likely allow now to talk to that computer in some way. This is no longer the case: firewalls partition the Internet into administrative domains that are isolated from each other except for rigidly controlled pathways. System administrators enforce policies about what can move through firewalls and how [...]”

Virtual Organizations in the Arigatoni Overlay Network — L. Liquori et al. 10

Arigatoni: Registration ModalitiesArigatoni: Registration Modalities

Registration of a GCU to the GBU leader of a colony belonging to the same current administrative domain of the GCU

Registration via remote tunneling of an GCU to another GBU leader of a colony belonging to a different administrative domain of the GCU

Summarizing, one GCU register to the GBU leader of the colony belonging to the same administrative domain in which it resides and to some other GBUs via tunneling

Virtual Organizations in the Arigatoni Overlay Network — L. Liquori et al. 11

Arigatoni: Unregistration ModalitiesArigatoni: Unregistration Modalities

Unregistration of a GCU when there are no pending services demanded or requested to the leader GBU of the colony it belongs. The colony accepts the unregistration only if the colony itself will not be corrupted

A GBU cannot unregister from its own colony (i.e. it cannot discharge itself). For fault tolerance purposes, a GBU can be faulty. In that case, the GCUs will unregister one after the other and the colony will “disappear”

Once a GCU has been disconnected from a colony belonging to any administrative domain, it can migrate in another colony belonging to any other administrative domain (“emigrant” model)

Virtual Organizations in the Arigatoni Overlay Network — L. Liquori et al. 12

Arigatoni Overlay Network@glanceArigatoni Overlay Network@glance

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GCU’s Registration UnregistrationGCU’s Registration Unregistration

A GCU join a Colony

A GCU leave a Colony

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COL’s Registration UnregistrationCOL’s Registration Unregistration Colony Registration

Colony Unregistration

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Colonies not in the Same DomainColonies not in the Same Domain Linking two Colonies

UnLinking two Colonies

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Contextual and CongruenceContextual and Congruence Morris like rules

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Join/Leave a Colony in a Different Join/Leave a Colony in a Different Administrative DomainAdministrative Domain Individual in IP1 knows “friends” inhabitant of the

colony in IP2. Then, via an explicit ssh the laptop can log into the desktop and send a global request to the “mother colony”. As such, the laptop works in its local mode while the desktop works in global mode. No ad hoc rewriting rules in the Arigatoni virtual organization

Individual in IP1 knows no inhabitant of the colony in IP2, but it knows the address of the leader of the colony. Via ssh-tunnel a virtual clone of the remote individual on behalf of the leader of the colony is created and registered. As such, the laptop works in local mode while the clone works in global mode. This mechanism is reminiscent of the Virtual Private Network technology (VPN). We need 4 Extra Rewriting Rules

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GCU not in the Same DomainGCU not in the Same Domain

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Colonies not in the Same DomainColonies not in the Same Domain

Virtual Organizations in the Arigatoni Overlay Network — L. Liquori et al. 20

Free Riders in Overlay NetworksFree Riders in Overlay Networks In economics and political science, free riders are

actors who consume more than their fair share of a resource, or shoulder less than a fair share of the costs of its production …The free rider problem is the question of how to prevent free riding from taking place, or at least limit its negative effects …

Because the notion of “fairness” is a subject of controversy, free riding is usually only considered to be an economic “problem” when it leads to the non-production or under- production of a public good, and thus to Pareto inefficiency, or when it leads to the excessive use of a common property resource.

[From Wikipedia].

Virtual Organizations in the Arigatoni Overlay Network — L. Liquori et al. 21

Arigatoni Rules to “Fire” Free Ridings Arigatoni Rules to “Fire” Free Ridings

Virtual Organizations in the Arigatoni Overlay Network — L. Liquori et al. 22

GC issues service request to the system via its GB leader

The GB finds “some” GCs able to serve the request using an O.O. lookup

Report “some” GCs that accepted to serve it

GC talks with the GCs in a P2P fashion

Simple Constraint Language + First-order Matching algos à la Nancy’s Rho-calculus

Arigatoni

[Type = CPU][Time < 10s][Type = CPU][Time < 10s]

[Type = CPU][Type < 20s][Type = CPU][Type < 20s]

[Type = CPU][Mem < 10M][Type = CPU][Mem < 10M]

[Type = CPU][Time > 5s][Type = CPU][Time > 5s]

Service RequestGCA

S’

S1

S2

S3

GCB GCC

Glance of Resource Discovery Protocol Glance of Resource Discovery Protocol I2CS, Neuchatel, June 06, LENSI2CS, Neuchatel, June 06, LENS

Virtual Organizations in the Arigatoni Overlay Network — L. Liquori et al. 23

Glance of Resource Discovery Protocol Glance of Resource Discovery Protocol I2CS, Neuchatel, June 06, LNCSI2CS, Neuchatel, June 06, LNCS

S = [Type = CPU] & [Time > 10s]

Selective intra-colony search mode

uses less resources

can lead to poor delay

Exhaustive search mode

uses more resources

can improve delay

A

C

E

D

F G H

GC1

GC2

[Type = CPU][Time < 200][Type = CPU][Time < 200]

S2

[Type = MEM][Capa < 20][Type = MEM][Capa < 20]

[Type = CPU][Time < 20][Type = CPU][Time < 20]

S1

GC3

S3

[Type = CPU][Time > 10][Type = CPU][Time > 10]

Selective intra-colony searchExhaustive intra-colony search

B

Virtual Organizations in the Arigatoni Overlay Network — L. Liquori et al. 24

Experimental EvaluationExperimental Evaluation

Sample Topology GeorgiaTech-ITM (transit-stub)

Virtual Organizations in the Arigatoni Overlay Network — L. Liquori et al. 25

The Rationale of the SimulationThe Rationale of the Simulation We start with a fully connected topology The rationale is apply a number of rewriting

rules de/connecting GCU/GBU from the topology and then do the experiment

We study the impact of the disconnections using a variable [0..100]%

Virtual Organizations in the Arigatoni Overlay Network — L. Liquori et al. 26

Average Acceptation RatioAverage Acceptation Ratio

a

Virtual Organizations in the Arigatoni Overlay Network — L. Liquori et al. 27

Service Acceptation RatioService Acceptation Ratio b

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Standard Deviation of Accept RateStandard Deviation of Accept Rate

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Real Example in a Grid ArenaReal Example in a Grid Arena

Virtual Organizations in the Arigatoni Overlay Network — L. Liquori et al. 30

In Fine…In Fine… Arigatoni: Lightweight Overlay Network for dynamic

Resource Discovery. Achievements Intermittence

Generality

Asynchronicity

Scalability

Current, future work More functionalities (service instances, conjunctions)

Statistical model of the framework

Protoimplementation,deployment (PlanetLab,G5000)

Virtual Organizations in the Arigatoni Overlay Network — L. Liquori et al. 31

Questions?Questions?

Virtual Organizations in the Arigatoni Overlay Network — L. Liquori et al. 32

Resource Discovery ProtocolResource Discovery Protocol Routing tables maintained at each GB

⇒ set of services registered in each Colony Always search in own colony first: encapsulation

Local colony of GCs Other sub-colonies in Colony Other Colonies via the GB leader = OO delegation-

based Service request for service S’

Search GCs in local colony that accept to serve S’ Search in other sub-colonies If none are found, delegate to the leader GB …

Looks much like “method lookup” in OO languages…

Virtual Organizations in the Arigatoni Overlay Network — L. Liquori et al. 33

Context: Overlay NetworksContext: Overlay Networks

Physical Network

Overlay Network

AA

BB

CC

Focus on the application layer

Focus on the application layer

Treat multiple hops through IP network as one hop in an overlay network

Treat multiple hops through IP network as one hop in an overlay network

Virtual Organizations in the Arigatoni Overlay Network — L. Liquori et al. 34

Resource Discovery ProtocolResource Discovery Protocol

Virtual Organizations in the Arigatoni Overlay Network — L. Liquori et al. 35

Resource Discovery Protocol (Sketch)Resource Discovery Protocol (Sketch)

Type=CPUTime>10Type=CPUTime>10

Type=MEMCapa < 20Type=MEMCapa < 20

S3

GC3

A

C

B

E

D

F G H

GC1

GC2

Type =CPUTime<200Type =CPUTime<200

S2

Type=CPUTime < 20Type=CPUTime < 20

S1

Encapsulation of resources in colonies

Always search in colony first

Delegate if no GCs are found

⇒ prevents super brokers from begin overloaded