prefix forwarding for publish/subscribe

Motivation Overview Routing Tree Forwarding Prefix Tree TO Evaluation Summary 1 of 28 slides

Prefix Forwarding for Publish/SubscribeDEBS 2007

Zbigniew Jerzak, Christof Fetzer

Dresden University of Technology

Friday 22nd June, 2007

{Zbigniew.Jerzak, Christof.Fetzer}@tu-dresden.de

Prefix Forwarding for Publish/Subscribe Zbigniew Jerzak, Christof Fetzer

Event forwarding in SIENA [CRW01]

0 5000 10000 15000 20000 25000

filter count

siena poset

Filter insertion in SIENA

0 5000 10000 15000 20000 25000

filter count

siena poset

Background

I Decoupled [EFGK03] communication...I ...between publishers and subscribers via routersI ...using filters (subscriptions)I ...and events (notification)I ...based on their content

Background

I Decoupled [EFGK03] communication...I ...between publishers and subscribers via routersI ...using filters (subscriptions)

I {movie=”star wars” AND price<15}I ...and events (notification)I ...based on their content

Background

I Decoupled [EFGK03] communication...I ...between publishers and subscribers via routersI ...using filters (subscriptions)I ...and events (notification)

I {movie=”indiana jones” format=”DVD” price=30}I ...based on their content

Background

Our Approach

Match event only once

Our Contributions

I New routing structure and algorithmsI Routing Tree (matching)I Forwarding Prefix Tree (forwarding)

I Content and forwarding decouplingI No false negatives

Outline – Subscribing

Outline – Publishing

Routing Tree

I stores filtersI used for event matching and forwarding

Routing Tree – Filter Insertion

Forwarding Prefix Tree

I Represents the prefixI Assigned by the Edge Router

Event Matching

Event Forwarding

The Problem

I Routing Trees are not deterministicI ...but we could fix it

I The whole system is non deterministicI ...and we want 0 false-positives

The Problem

I Routing Trees are not deterministicI ...but we could fix it

I The whole system is non deterministicI ...and we want 0 false-positives

Updating TO

Updating RT

I Push update from the TO the RTI Hey, and what about decoupling?

I TO maintains the content of the filtersI More precisely - insertion order

I Routers associate their view of network with received RT

TO serializes subscriptions

Updating RT

Evaluation Environment

I SIENA 1.5.4I Stochastic Simulation in Java (SSJ) libraryI AOL 500k User Session CollectionI Google stats collected on 28th May 2007I Large Graph Layout (LGL)

I SIENA 1.5.4I Stochastic Simulation in Java (SSJ) library

I umontreal.iro.lecuyer.randvar.*I umontreal.iro.lecuyer.rng.*

I AOL 500k User Session CollectionI Google stats collected on 28th May 2007I Large Graph Layout (LGL)

I SIENA 1.5.4I Stochastic Simulation in Java (SSJ) libraryI AOL 500k User Session Collection

I ∼20M web queriesI ∼650k usersI 3 months

I Google stats collected on 28th May 2007I Large Graph Layout (LGL)

Using AOL 500K – Subscriptions

I AOL log line:AnonID | Query | QueryTime | <ItemRank> | <ClickURL>

I Subscriptions:I {q Op.SS Query}I {q Op.PF Query}I LocalSubscriber≡AnonID

I Publications?

Using AOL 500K – Publications

P1(sub) =google results(sub)total indexed pages

1 f o r ( sub : a l l S u b s c r i p t i o n s ){2 i f (P1( sub)>Random . nextDoub le ( ) ){3 p u b l i c a t i o n s t r i n g+=sub . a t t r i b u t eV a l u e ( ) ;4 }5 }

Test Data

I 40k queries

0 10000 20000 30000 40000 50000 60000 70000 80000

query #

hits for query

Figure 1: 10 queries/user

0 5000 10000 15000 20000 25000 30000 35000 40000 45000hit

query #

hits for query

Figure 2: ≥ 4k queries/user

Routing Tree

Figure 3: RT – Op.SS, 10 q/u

Forwarding Prefix Tree (FPT)

1 2 3 4 5 6

FPT 10 queries (246 nodes)FPT >=4k queries (175 nodes)

Figure 4: FPT – Op.SS

Event forwarding in SIENA vs Prefix Tree

0 5000 10000 15000 20000 25000

filter count

prefix treesiena poset

Figure 5: Op.SS, 10 queries/userPrefix Forwarding for Publish/Subscribe Zbigniew Jerzak, Christof Fetzer

Filter storage in SIENA vs Prefix Tree

0 5000 10000 15000 20000 25000

filter count

prefix treesiena poset

Figure 6: Op.SS, 10 queries/userPrefix Forwarding for Publish/Subscribe Zbigniew Jerzak, Christof Fetzer

Summary

I Match only once per eventI Prefix to decouple content and routingI Tree Optimizer to handle indeterminism

Cool stuff to do

I RT deltasI Forwarding efficiencyI Autonomic configurationI FPT accuracy & false positivesI Publish/Subscribe Testing System

Thank You!http://wwwse.inf.tu-dresden.de/zib/

References

Antonio Carzaniga, David S. Rosenblum, and Alexander L. Wolf.Design and evaluation of a wide-area event notification service.ACM Trans. Comput. Syst., 19(3):332–383, 2001.

Patrick Th. Eugster, Pascal A. Felber, Rachid Guerraoui, and Anne-MarieKermarrec.The many faces of publish/subscribe.ACM Comput. Surv., 35(2):114–131, 2003.