XSiena: The Content-Based Publish/Subscribe System

Introduction Matching and Routing Surviving Failure Summary 1 of 25 slides

XSiena: The Content-BasedPublish/Subscribe System

Zbigniew Jerzak

Technisches Universitat Dresden, Fakultat Informatik

Wednesday 30th September, 2009

XSiena: The Content-Based Publish/Subscribe System Zbigniew Jerzak


Outline

IntroductionEvolution of NetworkingIntroduction to Publish/Subscribe Systems

Matching and RoutingSelection and Delivery of Events

Surviving FailureSoft State Content-based Publish/Subscribe Systems

SummaryContributions of this Thesis and Dissemination



Telephone Systembased on: [Jac06]

I Almon B. Strowger (1891)

I Implications:I no transmission possible

prior to path set upI path setup costs dominate

transmission costsI high probability of failure

Figure 1: The Strowger Switch – source:US patent 447918



Telephone Systembased on: [Jac06]

I Almon B. Strowger (1891)

I Implications:I no transmission possible

prior to path set upI path setup costs dominate

transmission costsI high probability of failure

Figure 1: The Strowger Switch – source:US patent 447918



Packet Switching

I The ideas of packet andswitching [Bar64]

I TCP/IP [CK74]

I Implications:I no support for the N-to-M

communicationI data has a location not a

content

Figure 2: Donald Davies (left) and PaulBaran (right) – source: Making TheModern World: The Early Internet



Packet Switching

I The ideas of packet andswitching [Bar64]

I TCP/IP [CK74]

I Implications:I no support for the N-to-M

communicationI data has a location not a

content

Figure 2: Donald Davies (left) and PaulBaran (right) – source: Making TheModern World: The Early Internet



Content-Based Publish/Subscribe [RW97]

I No explicit addressing (data is the address)

I Decoupling: space, time and synchronization [EFGK03]

I Implications:I No duplication of data flowsI Dynamism and agility



Content-Based Publish/Subscribe [RW97]

I No explicit addressing (data is the address)

I Decoupling: space, time and synchronization [EFGK03]

I Implications:I No duplication of data flowsI Dynamism and agility



Publish/Subscribe Systems

I Instantiation of thecontent-based networking

I Concepts:I Publishers: produce dataI Subscribers: register for

dataI Events: dataI Brokers: network

































Subscriptions and Events

I Event: a set of values ani = avitemp︸︷︷︸an0

= 20︸︷︷︸av0

; press︸︷︷︸an1

= 1025︸︷︷︸av1

I Subscription: a conjunction of predicates pi ()

temp > 30︸︷︷︸p0()

AND press < 900︸︷︷︸p1()



Subscriptions and Events

I Event: a set of values ani = avitemp︸︷︷︸an0

= 20︸︷︷︸av0

; press︸︷︷︸an1

= 1025︸︷︷︸av1

I Subscription: a conjunction of predicates pi ()

temp > 30︸︷︷︸p0()

AND press < 900︸︷︷︸p1()



Content-Based Matching and Routing

I Two main routing schemes:I subscription-basedI advertisement-based















































































Matching and Routing Issues

I Problem: evaluate every subscription/advertisement withevery event at every broker

I Solution: reuse matching results [JF07, JF08]I Only one content-based match per event

1. Disseminate subscriptions

2. Match events against subscriptions in the 1st broker

3. Piggyback (and reuse) match results on the event



















Bloom Filter-Based Routing

1. Subscription routing

2. Event publication

3. Content-based matching

4. Match results encoding

5. Event forwarding

6. Encoding-based matching

7. Delivery








5. Event forwarding


7. Delivery








5. Event forwarding


7. Delivery








5. Event forwarding


7. Delivery








5. Event forwarding


7. Delivery








5. Event forwarding


7. Delivery








5. Event forwarding


7. Delivery








5. Event forwarding


7. Delivery








5. Event forwarding


7. Delivery



Matching with Bloom Filters [Blo70]

I Two phase approach:

1. Encode matching result for every predicate:

∀{ani ,avj}∈e,pk∈S : pk({ani , avj}) = 1 ⇒ bfe ← h(pk)

2. Check if matching predicates form a subscription

∀pk∈bfe ,si inS : si = {pk} ⇒ select si



Matching with Bloom Filters [Blo70]

I Two phase approach:

1. Encode matching result for every predicate:

∀{ani ,avj}∈e,pk∈S : pk({ani , avj}) = 1 ⇒ bfe ← h(pk)

2. Check if matching predicates form a subscription

∀pk∈bfe ,si inS : si = {pk} ⇒ select si



Result

0

200

400

600

800

1000

1200

2 4 6 8 10 12 14 16 18 20 400

410

420

430

440

450m

atch

tim

e [m

s]

avg b

its

/ ev

ent

number of filters (1000s)

match speed (counting)match speed (sbstree)

avg bits / event (counting)avg bits / event (sbstree)

Figure 3: Matching does not depend on the number of filters



The Need for the Soft State

I Problem: transient failures in a distributed systemI Solution: soft state

I can be lost without permanent disruption of systemfeatures [Cla88]

I broker crash =⇒ loss only of the state owned by it



Goal of the Soft State [JF09]







I Problem: existing approaches are not realisticI Solution: use a practical system model [CF99]:

I realistic assumptions about the type and frequency of failuresI implementation in a real, distributed environment (PlanetLab)



Our Approachbased on: [MJH+05]



























Challenges I

0.25

0.5

0.75

1

10-1

100

101

102

103

104

CD

F

rtt [ms]

LAN: inf.tu-dresden.deMAN: tu-dresden.de

WAN: tu-dresden->tu-berlin

Figure 4: Network latencies cannot be predicted, nor bounded!



Challenges I

0.25

0.5

0.75

1

100

101

102

103

104

105

CD

F

request processing time [µs]

Lab PCPlanetLab node

Figure 4: Request processing times cannot be predicted, nor bounded!



Challenges II



Challenges II



Challenges II



Challenges II



Challenges II



Challenges II



Challenges II



Challenges II



Challenges II



Challenges II



Solution

Use upper bound on message propagation delayto estimate the link uncertainty

I Link uncertainty:I a measure of the link latency variationI calculated using upper bound on propagation delay [JFF07]I [ubmax − ubmin]window

Extend the advertisement/subscription validityusing calculated link uncertainty



Solution






Solution






Extending the Lease Time















Result

0

20

40

60

80

100

1 10 100

tota

l ti

me w

ith

ou

t ad

vert

isem

en

t [%

]

time [s]

uoit.ca - extuoit.ca - noext

hiit.fi - exthiit.fi - noext

Figure 5: Decreased total time without advertisement



Summary

I Content-based matching in the application layer [JF07, JF08]

I Fail-aware soft state system [JFF07, JF09]

I Contributed to StreamMine [FBFJ]

I XSiena: http://wwwse.inf.tu-dresden.de/xsiena/


http://wwwse.inf.tu-dresden.de/xsiena/


Thank You!



References I

Paul Baran.

On distributed communications networks.IEEE Transactions on Communications Systems, 12(1):1–9, March 1964.

Burton H. Bloom.

Space/time trade-offs in hash coding with allowable errors.Communications of the ACM, 13(7):422–426, 1970.

Flaviu Cristian and Christof Fetzer.

The timed asynchronous distributed system model.IEEE Transactions on Parallel and Distributed Systems, 10(6):642–657, June 1999.

Vinton G. Cerf and Robert E. Kahn.

A protocol for packet network intercommunication.IEEE Transactions on Communications, 22(5):637–648, May 1974.

D. Clark.

The design philosophy of the DARPA internet protocols.In SIGCOMM ’88: Symposium proceedings on Communications architectures and protocols, pages 106–114,New York, NY, USA, 1988. ACM.

Patrick Th. Eugster, Pascal A. Felber, Rachid Guerraoui, and Anne-Marie Kermarrec.

The many faces of publish/subscribe.ACM Comput. Surv., 35(2):114–131, 2003.



References II

Christof Fetzer, Andrey Brito, Robert Fach, and Zbigniew Jerzak.

To appear in: Handbook of Research on Advanced Distributed Event-Based Systems, Publish/Subscribeand Message Filtering Technologies, chapter StreamMine.IGI Global.

Van Jacobson.

A new way to look at networking.In Google Tech Talk, August 2006.

Zbigniew Jerzak and Christof Fetzer.

Prefix forwarding for publish/subscribe.In Hans-Arno Jacobsen, Gero Muhl, and Michael A. Jaeger, editors, DEBS ’07: Proceedings of the 2007Inaugural International Conference on Distributed Event-Based Systems, volume 233 of ACM InternationalConference Proceeding Series, pages 238–249, Toronto, Ontario, Canada, June 2007. ACM.


Bloom filter based routing for content-based publish/subscribe.In Roberto Baldoni, editor, DEBS ’08: Proceedings of the second international conference on Distributedevent-based systems, volume 332 of ACM International Conference Proceeding Series, pages 71–81, Rome,Italy, July 2008. ACM.


Soft state in publish/subscribe.In DEBS ’09: Proceedings of the third international conference on Distributed Event-Based Systems,Nashville, TN, USA, July 2009. ACM.



References III

Zbigniew Jerzak, Robert Fach, and Christof Fetzer.

Fail-aware publish/subscribe.In NCA ’07: Proceedings of the Sixth IEEE International Symposium on Network Computing andApplications, pages 113–125, Cambridge, MA, USA, July 2007. IEEE Computer Society.

Gero Muhl, Michael A. Jaeger, Klaus Herrmann, Torben Weis, Andreas Ulbrich, and Ludger Fiege.

Self-stabilizing publish/subscribe systems: Algorithms and evaluation.In Euro-Par 2005 Parallel Processing, volume 3648/2005, pages 664–674. Springer Berlin / Heidelberg,2005.

David S. Rosenblum and Alexander L. Wolf.

A design framework for internet-scale event observation and notification.In Mehdi Jazayeri and Helmut Schauer, editors, 6th European Software Engineering Conference Held Jointlywith the 5th ACM SIGSOFT Symposium on Foundations of Software Engineering, volume 1301 of LectureNotes in Computer Science, pages 344–360, Zurich, Switzerland, September 1997. ACM.


Technology

XSiena: The Content-Based Publish/Subscribe System