Post on 12-Apr-2018
transcript
7/21/2019 Baldoni Pub
1/74
MINEMA Summer School 1
Universit di Roma La Sapienza
Dipartimento di Informatica e Sistemistica
The Publish/SubscribeCommunication Paradigm and itsApplication to Mobile Systems
Roberto BaldoniDipartimento di Informatica e SistemisticaUniversit degli Studi di Roma La Sapienza
7/21/2019 Baldoni Pub
2/74
MINEMA Summer School
Universit di Roma La Sapienza
Dipartimento di Informatica e Sistemistica
Outline
Introduction
Basics of pub/sub communication systems Subscription models
Architectural models
Event Routing
Impact of mobility
7/21/2019 Baldoni Pub
3/74
MINEMA Summer School "
Universit di Roma La Sapienza
Dipartimento di Informatica e Sistemistica
Subscribersregister subscriptionscharacterizing information interests
Publisherspublish notifications withinteresting information
Middleware determines whichsubscriptions match which notifications
Middleware delivers notifications tomatching subscribers
Introduction: The Publish/Subscribe
Communication Style
Publisher SubscriberPublish/Subscribe Middleware
7/21/2019 Baldoni Pub
4/74
MINEMA Summer School #
Universit di Roma La Sapienza
Dipartimento di Informatica e Sistemistica
Inroduction The Publish/Subscribe
Paradigm Publish/Subscribe pub/sub!" a po#erful abstractionfor building distributed applications $essage%based& anonymous communication
Participants are decoupled
in space" no need to be connected or even 'no# each other in flo#" no need to be synchroni(ed
in time" no need to be up at the same time
)ood solution for highly dynamic& decentrali(edsystems e*g*& #ired environments #ith huge
numbers of publishers and subscribers& $A+E,s&P-P etc!
$any research issues& involving several researchareas e*g*& systems& soft#are eng*& databases etc!
7/21/2019 Baldoni Pub
5/74
MINEMA Summer School 5
Universit di Roma La Sapienza
Dipartimento di Informatica e Sistemistica
Introduction
.idely popular both in the industry and in theresearch
Industry solutions for pub/sub are almost centrali(ed
Research has mainy to face the scalability aspect
Applications
Stoc' information delivery
Auction system
Air traffic control
*etc
$any names for pub/sub systems" notification
service& data distribution service
7/21/2019 Baldoni Pub
6/74
MINEMA Summer School $
Universit di Roma La Sapienza
Dipartimento di Informatica e Sistemistica
Basic Interaction Model
S0
S-
S1
publisherssubscribers
2IB$3
2A4$E3
2A4$E3
subscription
IB$" %1&56
A4$E" 78&06
IB$" 7-&60
event
S0" IB$S-" A4$E
S1" A4$E
notification serviceIB$" %1&56
IB$" 0-&60
A4$E" 78&06
A4$E" 78&06
notification
7/21/2019 Baldoni Pub
7/74
MINEMA Summer School %
Universit di Roma La Sapienza
Dipartimento di Informatica e Sistemistica
istributed !oti"ication Ser#ice
S0
S-
S1
2IB$3
2A4$E3
2A4$E3
IB$" %1&56
A4$E" 78&06
IB$" 7-&60
notification serviceIB$" %1&56
IB$" 0-&60
A4$E" 78&06
A4$E" 78&06
Matching
9etermining the recipients for an event
Routing
9elivering a notification to all the recipients
S1" A4$E
S-" A4$E
S0" IB$
broker
7/21/2019 Baldoni Pub
8/74
MINEMA Summer School &
Universit di Roma La Sapienza
Dipartimento di Informatica e Sistemistica
Research ,opics
System architecture
Efficient routing algorithm
Reliable messaging sending the :oS issue!
Security Special application issues
$illions of users
$obile environment
P-P
Sensors net#or's*
7/21/2019 Baldoni Pub
9/74
MINEMA Summer School '
Universit di Roma La Sapienza
Dipartimento di Informatica e Sistemistica
Pub/Sub Systems
IBM )ryphon
Stanford SI;, and more
CUBoulder Siena
!rance thers ?$
7/21/2019 Baldoni Pub
10/74
MINEMA Summer School 1!
Universit di Roma La Sapienza
Dipartimento di Informatica e Sistemistica
Subscription Models
Topic-Based [Oki et al. 93]:
%events are divided in topics%subscribers subscribe for a single
topic
Content-Based [Carzaniga et al2001]:%subscriptions are generic Cueries
S:
7/21/2019 Baldoni Pub
11/74
MINEMA Summer School 11
Universit di Roma La Sapienza
Dipartimento di Informatica e Sistemistica
Pub/Sub $ariants: Topic%based
Event space is divided in topics&
corresponding to logical channels
Participants subscribe for a topic and publish
on a topic
Receivers for an event are 'no#n a priori
4hannel G )roup
,herefore often eploit net#or'%level multicast )roup communication
7/21/2019 Baldoni Pub
12/74
MINEMA Summer School 1
Universit di Roma La Sapienza
Dipartimento di Informatica e Sistemistica
Content Based pub%sub: e#ent schema Subscriptions and events defined over an
n%dimensional event space %E*g* StockName = ACME andchange < -3)
Subscription" conFunction of constraints
eventsubscription
Content&ased
su&scriptionscan
include range
constraints
a0
a-
7/21/2019 Baldoni Pub
13/74
MINEMA Summer School 1"
Universit di Roma La Sapienza
Dipartimento di Informatica e Sistemistica
Pub/Sub $ariants: Content%based
Receivers are calculated for each event being
published
Eploiting multicast is not straighfor#ard
=o# are subscribers assigned to groupsH
2A4$E3& change %1
2A4$E3
A4$E&changeG%6
A4$E& change G %-
7/21/2019 Baldoni Pub
14/74
MINEMA Summer School 1#
Universit di Roma La Sapienza
Dipartimento di Informatica e Sistemistica
Topic #s& Content
,opic%based pub/sub
Recipients are 'no#n a%priori
$any efficient implementations eist" e*g* tib
7/21/2019 Baldoni Pub
15/74
MINEMA Summer School 15
Universit di Roma La Sapienza
Dipartimento di Informatica e Sistemistica
Architectural Model o" a pub/sub
Netor* Multicasting
+ro*er layer oerlay
Structure .erlay
7/21/2019 Baldoni Pub
16/74
MINEMA Summer School 1$
Universit di Roma La Sapienza
Dipartimento di Informatica e Sistemistica
Architectural Model o" a pub/sub
+et#or' $ulticasting se of multicast net#or'ing facilities also at data lin'
level!
Bro'er layer overlay
Based on transport level connections bet#een nodes
=ierarchical 9ecision tree from publisher to
subscribers!
ndirected Acyclic graph spanning all bro'ers Structured >verlay
9=, abstracting from physical nodes!
7/21/2019 Baldoni Pub
17/74
MINEMA Summer School 1%
Universit di Roma La Sapienza
Dipartimento di Informatica e Sistemistica
'$'!T #s S(BSC)IPTIO! )O(TI!*
Etreme solutions Sol 0 event flooding!
flooding of events in the notification event bo
each subscription stored only in one place #ithin
the notification event bo $atching operations eCual to the number of
bro'ers
Sol - subscription flooding!
each subscription stored at any place #ithin thenotification event bo
each event matched directly at the bro'er #herethe event enters the notification event bo
7/21/2019 Baldoni Pub
18/74
MINEMA Summer School 1&
Universit di Roma La Sapienza
Dipartimento di Informatica e Sistemistica
/onnectiity
0ro*ers u0lisherssu0scri0ers
Handling subscriptions
Identification of intermediate routing solutions
7/21/2019 Baldoni Pub
19/74
MINEMA Summer School 1'
Universit di Roma La Sapienza
Dipartimento di Informatica e Sistemistica
/onnectiity
0ro*ers u0lishers
Su0scrition 2artitioning (s)
s
su0scri0ers
Handling subscriptions: subscription partitioning i.e., where to stores
Identification of intermediate routing solutions
7/21/2019 Baldoni Pub
20/74
MINEMA Summer School !
Universit di Roma La Sapienza
Dipartimento di Informatica e Sistemistica
/onnectiity
0ro*ers u0lishers
Su0scrition 2artitioning (s)
s
su0scri0ers
Su0scrition 3outing
Handling subscriptions: subscription routing i.e., how to brings
there
Identification of intermediate routing solutions
7/21/2019 Baldoni Pub
21/74
MINEMA Summer School 1
Universit di Roma La Sapienza
Dipartimento di Informatica e Sistemistica
Su0scrition 3outing
Su0scrition 2artitioning (s)
/onnectiity
su0scri0ers 0ro*ers u0lishers
e
Handling events
Identification of intermediate routing solutions
7/21/2019 Baldoni Pub
22/74
MINEMA Summer School
Universit di Roma La Sapienza
Dipartimento di Informatica e Sistemistica
Su0scrition 3outing
Su0scrition 2artitioning (s)
/onnectiity
su0scri0ers 0ro*ers u0lishers
e
Eent 2artitioning (e)
Handling events: Event Partitioning i.e., where to match e
Identification of intermediate routing solutions
7/21/2019 Baldoni Pub
23/74
MINEMA Summer School "
Universit di Roma La Sapienza
Dipartimento di Informatica e Sistemistica
Su0scrition 3outing
Su0scrition 2artitioning (s)
/onnectiity
su0scri0ers 0ro*ers u0lishers
e
Eent 2artitioning (e)
Handling events: Event Routing i.e., How to bring e there
Eent 3outing
Identification of intermediate routing solutions
7/21/2019 Baldoni Pub
24/74
MINEMA Summer School #
Universit di Roma La Sapienza
Dipartimento di Informatica e Sistemistica
Matching (e)
Handling events: Event Matching i.e., define the set of recipients of e
Su0scrition 3outing
Su0scrition 2artitioning (s)
/onnectiity
Eent 3outing
su0scri0ers 0ro*ers u0lishers
e
Eent 2artitioning (e)
Eent 3outing
Identification of intermediate routing solutions
U i i di R S i
7/21/2019 Baldoni Pub
25/74
MINEMA Summer School 5
Universit di Roma La Sapienza
Dipartimento di Informatica e Sistemistica
Su0scrition 3outing
Su0scrition 2artitioning (s)
/onnectiity
Eent 3outing
su0scri0ers 0ro*ers u0lishers
Notification routing
e
Handling events: otification Routing i.e., bring e to the destinations
Eent 2artitioning (e)
Matching (e)
Eent 3outing
Identification of intermediate routing solutions
U i it di R L S i
7/21/2019 Baldoni Pub
26/74
MINEMA Summer School $
Universit di Roma La Sapienza
Dipartimento di Informatica e Sistemistica
Su0scrition 3outing
Su0scrition 2artitioning
Eent 3outing
Notification routing
Eent 2artitioning (e)
Matching
Identification of intermediate routing solutions
U i it di R L S i
7/21/2019 Baldoni Pub
27/74
MINEMA Summer School %
Universit di Roma La Sapienza
Dipartimento di Informatica e Sistemistica
Basic Techni+ues "or intermediate
routing solutions ;iltering%based Routing J4ar(aniga et al*
-880K
ndirected Acyclic graph spanning all the bro'ers
Rende(%Lous Routing
J.ang et al* -88-K based on dynamic partitioning
of the event space among a set of bro'ers
J4astro et al -88-K based on 9=,
Universit di Roma La Sapienza
7/21/2019 Baldoni Pub
28/74
MINEMA Summer School &
Universit di Roma La Sapienza
Dipartimento di Informatica e Sistemistica
,iltering based routing
Identifying as soon as possible events that arenot interesting for any subscriber and arrest their
diffusion
4reating 2diffusion paths3 that lead tosubscribers for the event
4onstruction of a diffusion path reCuires routing
info to be maintained at bro'ers
Routing information consists of a set of filtersaggregate of subscriptions! that are reachable
through that bro'er
Universit di Roma La Sapienza
7/21/2019 Baldoni Pub
29/74
MINEMA Summer School '
Universit di Roma La Sapienza
Dipartimento di Informatica e Sistemistica
,iltering based routing: Three main phases
Subscription for#arding" subscriptions filters!are propagated to every bro'er leaving state
along the path
$atching notification follo# bac'#ards! the
path set by subscriptions
Reducing subscription propagation
Avoiding subscription propagation #hen a filter
including the subscription has been alreadyfor#arded
Universit di Roma La Sapienza
7/21/2019 Baldoni Pub
30/74
MINEMA Summer School "!
Universit di Roma La Sapienza
Dipartimento di Informatica e Sistemistica
-
.
0
1
2
3
4
5
SI'!A,iltering%Based )outingSubscription ,orwarding
a
s1: price > 600
s1:as1:a
s1:1s1:1
s1:.s1:.
s1:-s1:-
s1:.s1:.
s1:3s1:3
s1:-s1:-
s1:1s1:1
s1:4s1:4
Universit di Roma La Sapienza
7/21/2019 Baldoni Pub
31/74
MINEMA Summer School "1
Universit di Roma La Sapienza
Dipartimento di Informatica e Sistemistica
-
.
0
2
3
4
5
SI'!A,iltering%Based )outingSubscription Merging
s1:1s1:1
s1:.s1:.
s1:3s1:3
s1:-s1:-
s1:1s1:1
s2: price > 700
b
s1:-s1:-
s1:.s1:.
s1:4s1:4
s1:1
s.:4
s1:1s.:4
s1:.
s.:0
s1:.s.:0
s1:4
s.:b
s1:4
s.:b
a
s1co#ers s2
1
s1co#ers s2
s1:as1:as1:a
s.:.
s1:a
s.:.slitter
slitter
Universit di Roma La Sapienza
7/21/2019 Baldoni Pub
32/74
MINEMA Summer School "
Universit di Roma La Sapienza
Dipartimento di Informatica e Sistemistica
-
.
0
1
2
3
4
5
SI'!A,iltering%Based )outing!oti"ication eli#ery
b
s1:1
s.:4
s1:1s.:4
s1:.s1:.
s1:3s1:3
s1:-s1:-
s1:1s1:1s1:-s1:-
s1:.
s.:0
s1:.s.:0
a s1:as.:.
s1:a
s.:.
s1:4
s.:b
s1:4
s.:b
n1matches s1n1matches s2
n1:
price = 8
Universit di Roma La Sapienza
7/21/2019 Baldoni Pub
33/74
MINEMA Summer School ""
Universit di Roma La Sapienza
Dipartimento di Informatica e Sistemistica
,iltering based routing
,radeoff bet#een subscription redundancyand subscription flooding
,he more the bro'ers a#are of anysubscription the earlier notifications that donot match any subscription are filtered out
,radeoff bet#een epressiveness of
subscription language and scalability Epressiveness compleity brings to flood filters
7/21/2019 Baldoni Pub
34/74
MINEMA Summer School "#
Universit di Roma La Sapienza
Dipartimento di Informatica e Sistemistica
)ende6 $ous )outing
Each event of the event space is o#ned by one or morereliability reasons! bro'ers
,hree functions"
S+!" -+ rende(%vous nodes of !
E+e!" -+ rende(%vous nodes of e! Ife S+! thenS+! E+e! intersection rule!
$ain characteristics"
4ontrolled subscriptions distribution
4ontrolled matching Better load balance
Universit di Roma La Sapienza
7/21/2019 Baldoni Pub
35/74
MINEMA Summer School "5
Universit di Roma La Sapienza
Dipartimento di Informatica e Sistemistica
Rendezvous-based routing
Each node is responsible for a partition of the event space Storing subscriptions& matching events
M
e
Probem" difficult to define mapping functions #hen the set of
nodes changes over time
M
M
M
M
eM
Universit di Roma La Sapienza
7/21/2019 Baldoni Pub
36/74
MINEMA Summer School "$
p
Dipartimento di Informatica e Sistemistica
)ende6%$ous routing based on 7T
A matching publisher D subscriber must come up #iththe same hash 'eys based on the content
4istri0ute ash 6a0le
0uc*ets
istri0ute u0lish7su0scri0e system
Universit di Roma La Sapienza
7/21/2019 Baldoni Pub
37/74
MINEMA Summer School "%
p
Dipartimento di Informatica e Sistemistica
A matching publisher D subscriber must come up #iththe same hash 'eys based on the content
su0scri0er
home noe
4istri0ute ash 6a0le
0uc*ets
su0scrition
)ende6%$ous routing based on 7T
Universit di Roma La Sapienza
7/21/2019 Baldoni Pub
38/74
MINEMA Summer School "&
p
Dipartimento di Informatica e Sistemistica
A matching publisher D subscriber must come up #iththe same hash 'eys based on the content
u0lishersu0scri0er
home noe
4istri0ute ash 6a0le
0uc*ets
u0lication
su0scrition
)ende6%$ous routing based on 7T
Universit di Roma La Sapienza
7/21/2019 Baldoni Pub
39/74
MINEMA Summer School "'
Dipartimento di Informatica e Sistemistica
A matching publisher D subscriber must come up #iththe same hash 'eys based on the content
u0lishersu0scri0er
4istri0ute ash 6a0le
0uc*ets
su0scrition u0lication
home noe
)ende6%$ous routing based on 7T
Universit di Roma La Sapienza
7/21/2019 Baldoni Pub
40/74
MINEMA Summer School #!
Dipartimento di Informatica e Sistemistica
A matching publisher D subscriber must come up #iththe same hash 'eys based on the content
u0lishersu0scri0er
4istri0ute ash 6a0le
0uc*ets
su0scrition
u0lication
home noe
)ende6%$ous routing based on 7T
Universit di Roma La Sapienza
7/21/2019 Baldoni Pub
41/74
MINEMA Summer School #1
Dipartimento di Informatica e Sistemistica
)ende6%$ous routing 8Baldoni et al .994
D!"
'nmapping
#$%pub&sub
Subs a'mapping
'ppication
sub! pub! notify!
send! Foin!delivery! leave!
unsub!
Event space is
mapped into
the universe of
'eys fied!
>verlay
maintains
consistency of
+ mapping
Stateess mapping"%9oes not depend on
eecution history
subscriptions& node Foins
and leaves!
Universit di Roma La Sapienza
7/21/2019 Baldoni Pub
42/74
MINEMA Summer School #
Dipartimento di Informatica e Sistemistica
)ende6 $ous )outing
Problem" bottlenec'at hash buc'et nodes
Structuring subscribers as a multicast diffusion tree
Restrictions on the subscription language"
$apping bet#een multidimensional multi%typed subscriptions tothe uni or bi%dimensional space of a structured overlay is not
straightfor#ard e*g*& string manipulation!
Strong points" =andle inherently dynamic changes in the overlay
Universit di Roma La Sapienza
Di ti t di I f ti Si t i ti
7/21/2019 Baldoni Pub
43/74
MINEMA Summer School #"
Dipartimento di Informatica e Sistemistica
Summary o" routing
;iltering based routing"
>rder of hundreds of bro'ers
$anaged environment Rende(%vous routing based on 9=,
>rder of thousands of nodes
nmanaged environment
Universit di Roma La Sapienza
Di ti t di I f ti Si t i ti
7/21/2019 Baldoni Pub
44/74
MINEMA Summer School ##
Dipartimento di Informatica e Sistemistica
A "ew pub/sub systems
Universit di Roma La Sapienza
Di ti t di I f ti Si t i ti
7/21/2019 Baldoni Pub
45/74
MINEMA Summer School #5
Dipartimento di Informatica e Sistemistica
Pub/Sub Sysems: Tib/)$ 8O;i et al
9- ,opic Based
,#o level hierarchical architecture of bro'ers
deamons! on ,4P/IP Event routing is reali(ed through one diffusion
tree per subFect
Each bro'er 'no#s the entire net#or'
topology and current subscription
configuration
Universit di Roma La Sapienza
Dipartimento di Informatica e Sistemistica
7/21/2019 Baldoni Pub
46/74
MINEMA Summer School #$
Dipartimento di Informatica e Sistemistica
Pub/Sub systems: *ryphon 8IBM 99
4ontent based
=ierarchical tree from publishers to
subscribers ;iltering%based routing
$apping content%based to net#or' level
multicast
Universit di Roma La Sapienza
Dipartimento di Informatica e Sistemistica
7/21/2019 Baldoni Pub
47/74
MINEMA Summer School #%
Dipartimento di Informatica e Sistemistica
Pub/Sub Systems: SC)IB' 8Castro et al&
9. ,opic Based
Based on 9=, Pastry!
Rende(%vous event routing A random identifier is assigned to each topic
,he pastry node #ith the identifier closest to
the one of the topic becomes responsible forthat topic
Universit di Roma La Sapienza
Dipartimento di Informatica e Sistemistica
7/21/2019 Baldoni Pub
48/74
MINEMA Summer School #&
Dipartimento di Informatica e Sistemistica
M'*7OOT
4ontent Based
Based on Structured >verlay 4A+
$apping the subscription language and theevent space to 4A+ space
Subscription and event Routing eploit 4A+
routing algorithms
Universit di Roma La Sapienza
Dipartimento di Informatica e Sistemistica
7/21/2019 Baldoni Pub
49/74
MINEMA Summer School #'
Dipartimento di Informatica e Sistemistica
Mobile 'n#ironment
Universit di Roma La Sapienza
Dipartimento di Informatica e Sistemistica
7/21/2019 Baldoni Pub
50/74
MINEMA Summer School 5!
Dipartimento di Informatica e Sistemistica
Potential Ad#antages o" Pub/Sub "or
Mobile
7/21/2019 Baldoni Pub
51/74
MINEMA Summer School 51
Dipartimento di Informatica e Sistemistica
Impact o" mobility: In"ormation%Centric
Mobile
7/21/2019 Baldoni Pub
52/74
MINEMA Summer School 5
Dipartimento di Informatica e Sistemistica
Scenarios o" mobility
>ne%hop mobile net#or'
4entrali(ed vs distributed
dispatcher
NE9I -880& =uang -880
$ulti%hop mobile net#or'
$A+E,!
+o #ired infrastructure ;reCuent changes in
topology -88- no#!
Universit di Roma La Sapienza
Dipartimento di Informatica e Sistemistica
7/21/2019 Baldoni Pub
53/74
MINEMA Summer School 5"
pa t e to d o at ca e S ste st ca
One%hop wireless networ;
Problems in distributedpub/sub architecturesJ=uang -880K" failures&message losses anddisconnections
Important issues in areplicated pub%subJ=uang -880K"
>rderedness 4onsistency
4ompleteness
Universit di Roma La Sapienza
Dipartimento di Informatica e Sistemistica
7/21/2019 Baldoni Pub
54/74
MINEMA Summer School 5#
p
Mobile ad%hoc networ;: issues
4ostantly changing topology nicast is epensive #hile broadcast is cheap
4ommunication is less 2reliable3 than in #iredsystems due to disconnections driven by
mobility or volountary!
Effects on ho# to design a middle#are for
pub/sub e*g*& to improve performance of theevent dispatching system reducing thecompleity of epressiveness!
Universit di Roma La Sapienza
Dipartimento di Informatica e Sistemistica
7/21/2019 Baldoni Pub
55/74
MINEMA Summer School 55
p
,re+uent =uestions
9o #e really need comple subscription
languages for pub/sun over $A+E,sH
.hat is the right $A+E, modelHH Reconfiguration and a long period of stability or
;reCuent reconfigurations and short period of
stability
Partition or not partitionHHH
Allo#ing partitions means a lot of memory on boardOO
Universit di Roma La Sapienza
Dipartimento di Informatica e Sistemistica
7/21/2019 Baldoni Pub
56/74
MINEMA Summer School 5$
Architectural Model "or Mobile ad%
hoc networ;s
MA/
3outing 2u07su0
MA/
2S-3outing
Alication
Alication
MA/
Alication2u07su0
8uang et al !!,
+aloni et al !!5,
+ahemi et al !!59
8Mottola et al !!5,
+acon et al !!59
8Anceaume et al !!,
2icco et al !!"9
Universit di Roma La Sapienza
Dipartimento di Informatica e Sistemistica
7/21/2019 Baldoni Pub
57/74
MINEMA Summer School 5%
Topological )econ"iguration
MA/
3outing
Alication
/+ 2u07su0
82icco et al !!"9
!ssumption: the unerlying tree is *et connectean loo-free 0y some algorithm
SIENA is the target /+-2u07Su0 System
"arget: rearrange route traerse 0y eents
in resonse to changes in the toology of the
netor* of isatchers (0ro*ers)
Searation of concerns 0eteen connectiity layer
an eent isatching layer
Universit di Roma La Sapienza
Dipartimento di Informatica e Sistemistica
7/21/2019 Baldoni Pub
58/74
MINEMA Summer School 5&
Topological )econ"iguration
MA/
3outing
Alication
/+ 2u07su0
82icco et al !!"9
A+ lin* 0rea*age
/4 lin* formation
.riginal toology of the
eent isatching layer
Universit di Roma La Sapienza
Dipartimento di Informatica e Sistemistica
7/21/2019 Baldoni Pub
59/74
MINEMA Summer School 5'
Topological )econ"iguration
MA/
3outing
Alication
/+ 2u07su0
82icco et al !!"9
#trawman approach:
A an + trigger unsu0scritions
in their su0trees immeiately after
lin* 0rea*age
/ an 4 trigger su0scritions
immeiately hen lin* aears
Proposed approach:after lin* 0rea*age, A an +
elay the triggerring of
unsu0scritions in their su0trees/ an 4 trigger su0scritions
immeiately hen lin* aears
Rationale:
Su0scritions ersist longer on the tree an uon reconnection
su0scritions roagate only till the first slitter (e;ecuting the filter
merging)
Universit di Roma La Sapienza
Dipartimento di Informatica e Sistemistica
7/21/2019 Baldoni Pub
60/74
MINEMA Summer School $!
Topological )econ"iguration
Retrofitting reliability events lost duringreconfiguration! through gossip%based algorithms
.hat about partitioning or isolationHH
JAnceaume et al* -88-K assumes the net#or' doesnot partition for a time long enough to maintain the9A)
+e# approaches" Semi%deterministic routing 4ostaet al -886!
,rading subscription diffusion for better reaction totopology changes
Similar to RP in $A+E,
MA/
3outing
Alication
/+ 2u07su0
82icco et al !!"9
Universit di Roma La Sapienza
Dipartimento di Informatica e Sistemistica
7/21/2019 Baldoni Pub
61/74
MINEMA Summer School $1
Integration Approach
MA/
2S-3outing
Alication
8Mottola et al !!59
!ssumption: the unerlying tree is *et connecte
an loo-free 0y MA.4 their istance from bstrictly increase an their
istance to bstrictly ecrease>
2. bian bi+1are a?acent each other
4o not rely on a ositioning serice (a 0eacon
message is sufficient to estimate the istance
0eteen to a?acent noes)
6he aroach is fully istri0ute (each rocess
ecie autonomously if relaying the message)
Universit di Roma La Sapienza
Dipartimento di Informatica e Sistemistica
7/21/2019 Baldoni Pub
65/74
MINEMA Summer School $5
Broadcast%based approach
/+ 2u07su0
MA/
Alication
8+aloni et al !!59
+asic 0eaconing Algorithm:Each 0ro*er erioically sens a 0eacon containing
its filterA 0ro*er receiing 0eacons from a?acent 0ro*ers
form a hint ta0le
6he hint ta0le contains for each ro the last time
the 0eacon has 0een receie from a gien 0ro*er>
6his ermits a 0ro*er to etermine ho many
0eacons hae 0een misse from another 0ro*er> 6hisalue is set to:
if the to 0ro*ers neer come in contact! if they are currently aiacent
Universit di Roma La Sapienza
Dipartimento di Informatica e Sistemistica
7/21/2019 Baldoni Pub
66/74
MINEMA Summer School $$
Broadcast%based approach+asic @escreasing istance Algorithm: each eent carries a estination list (the @estimate list of 0ro*ers
intereste to that eent)
3eceiing an eent e, a 0ro*er bgoes in the @ready to forward
state for e if:
(i) 0 is aare of some 0ro*er not mentione in the estination listan matchnig the eent or
(ii) for some 0ro*er bcontaine in the estination list hose
hint is greater than the one store at b
If @ready to forward state for e, bscheules the actualforaring of eith a elay roortional to the loest hint
alica0le from the reiou stes
4uring the elay if breceies efrom some other neigh0ors it
ros the foraring
Universit di Roma La Sapienza
Dipartimento di Informatica e Sistemistica
7/21/2019 Baldoni Pub
67/74
MINEMA Summer School $%
Broadcast%based approach
/+ 2u07su0
MA/
Alication
8+aloni et al !!59
Universit di Roma La Sapienza
Dipartimento di Informatica e Sistemistica
7/21/2019 Baldoni Pub
68/74
MINEMA Summer School $&
Comparison
,opological reconfiguration +ot suitable for freCuent topology changes too
much overhead for updating the filter information!
not suitable for partition or isolation too much
overhead! this means no disconnected #or'Al#ay need cooperations among bro'ers
Broadcast%based Suitable for freCuent topology changes
4an adapt to partitions and isolations Epoit the broadcast nature of the environment
+odes do not need to cooperate
Universit di Roma La Sapienza
Dipartimento di Informatica e Sistemistica
7/21/2019 Baldoni Pub
69/74
MINEMA Summer School $'
)esearch irections "or pub/sub on MA!'Ts
Alications
3eference imlementations
3eal eloyments
/ature funamental ro0lemsose 0y ynamic 0ehaior
Please stop doing papers
on algorithms & sim
+utBmost imortant
Cos efinition an enforcement
2roerties of sarse netor*s
Universit di Roma La Sapienza
Dipartimento di Informatica e Sistemistica
7/21/2019 Baldoni Pub
70/74
MINEMA Summer School %!
ynamic istributed Systems
4ommon problems among implementingpub/sub on mobile ad%hoc net#or's and
reali(ing pub/sub on a structured overlay or
on a dense sensor net#or'
Similar techniCues have been used
9ynamic behavior becomes crucial in modern
distributed systems
It #ould be interested to studying general
solutions to such a common problem
Universit di Roma La Sapienza
Dipartimento di Informatica e Sistemistica
7/21/2019 Baldoni Pub
71/74
MINEMA Summer School %1
Than;s
Roberto Beraldi& )ianpaolo 4ugola& Antonino Lirgillito& RomanLitemberg& $ariangela 4ontenti& 4arlo $archetti& Sara ,ucci
Piergiovanni&
7/21/2019 Baldoni Pub
72/74
MINEMA Summer School %
A "ew re"erencesPaolo 4osta& $atteo $igliavacca& )ian Pietro Picco& )ianpaolo 4ugola" Epidemic Algorithms for Reliable 4ontent%Based Publish%Subscribe" An Evaluation* I494S -88@" 66-%60
Paolo 4osta& $atteo $igliavacca& )ian Pietro Picco& )ianpaolo 4ugola" Introducing reliability in content%basedpublish%subscribe through epidemic algorithms* 9EBS -881
)ian Pietro Picco& )ianpaolo 4ugola& Amy hio& Nune -886
P* 4osta * )*P* Picco& Semi Probabilistic content based%pub%subscribe ,o appear in Proceedings of the -6thInternational 4onference on 9istributed 4omputing Systems I494S U86!& 4olumbus& >hio& Nune -886
Universit di Roma La Sapienza
Dipartimento di Informatica e Sistemistica
7/21/2019 Baldoni Pub
73/74
MINEMA Summer School %"
Other re"erences
Universit di Roma La Sapienza
Dipartimento di Informatica e Sistemistica
7/21/2019 Baldoni Pub
74/74
Other re"erences