service‐centric networking with scaffold...principles of scaffold 1. service‐level naming...

Service‐centricnetworkingwithSCAFFOLD

MichaelJ.Freedman

PrincetonUniversity

withMatveyArye,PremGopalan,StevenKo,

ErikNordstrom,JenRexford,andDavidShue

Fromahost‐centricarchitecture

1960s


1960s1970s


1960s1970s

1990s

Toaservice‐centricarchitecture

1960s1970s

1990s

2000s


•  Userswantservices,agnosRcofactualhost/locaRon

•  Serviceoperatorsneed:replicaselecRon/loadbalancing,replicaregistraRon,livenessmonitoring,failover,migraRon,…

Hackstofakeservice‐centrismtoday

Layer4/7: DNSwithsmallTTLs HTTPredirects

Layer‐7switching

Layer3: IPaddressesandIPanycast

Inter/intrarouRngupdates

Layer2: VIP/DIPloadbalancers

VRRP,ARPspoofing

+Home‐brewedregistraRon,configuraRon,monitoring,…


•  Userswantservices,agnosRcofactualhost/locaRon

•  Serviceoperatorsneed:replicaselecRon/loadbalancing,replicaregistraRon,livenessmonitoring,failover,migraRon,…

•  Service‐levelanycastasbasicnetworkprimiRve

Twohigh‐levelquesRons

•  Moderatevision:Cannetworksupportaidself‐configuraRonforreplicatedservices?

•  Bigvision:Should“service‐centricnetworking”becomethenewthinwaistofInternet?

Namingasa“thinwaist”

•  Host‐centricdesign:TradiRonallyoneIPperNIC–  Loadbalancing,failover,andmobilitycomplicates–  Now:virtualIPs,virtualMACs,…

•  Content‐centricarchitecture:UniqueIDperdataobject–  DONA(Berkeley),CCN(PARC),…

•  SCAFFOLD:UniqueIDpergroupofprocesses–  EachmembermustindividuallyprovidefullgroupfuncRonality

–  Groupcanvaryinsize,distributedoverLANorWAN

Objectgranularitycanvarybyservice

=

SCAFFOLDObjectID

K-bit Admin Prefix Machine-readable ObjectID =

Google YouTube Service

FixedBit‐length

MemcachePar**on= Facebook Partition 243

= Comcast Mike’s Laptop

IZ–“Somewhereovertherainbow” = Google IZ – “Somewhere” video

SCAFFOLDas…

–  Cleanslatedesign

–  MulR‐datacenterarchitectureforsingleadministraRvedomain

•  Deployedoverlegacynetworks

•  Few/nomodificaRonstoapplicaRons

Target:SingleadministraRvedomain

•  Datacentermanagementmoreunified,simple,centralized

•  HostOSnet‐imagedandcanbefork‐liiupgraded

•  Alreadystrugglingtoprovidescalabilityandservice‐centrism

•  CloudcompuRnglessenimportanceoffixed,physicalhosts

X

DC 2 DC 1

Y

Backbone

Internet

X

YY

X

GoalsforService‐Centrism•  Handlingreplicatedservices

–  ControloverreplicaselecRonamonggroups

–  Controlofnetworkresourcessharedbetweengroups–  Handlingdynamicsamonggroupmembershipanddeployments

•  Handlingchurn–  Flexibility:Fromsessions,tohosts,todatacenters

–  Robustness:LargelyhidefromapplicaRons

–  Scalability:Localchangesshouldn’tneedtoupdateglobalinfo–  Scalability:Churnshouldn’trequireper‐clientstateinnetwork–  Efficiency:Wide‐areamigraRonshouldn’trequiretunneling

Clean-Slate Design

PrinciplesofSCAFFOLD1.  Service‐levelnamingexposedtonetwork

2.  AnycastwithflowaffinityasbasicprimiRve

3.  MigraRonandfailoverthroughaddressremapping–  AddressesboundtophysicallocaRons(aggregatable)

–  FlowsidenRfiedbyeachendpoint,notpairwise

–  Controlthroughin‐bandsignalling;statelessforwarders

4.  Minimizevisibilityofchurnforscalability–  Differentaddr’sfordifferentscopes(successiverefinement)

5.  Tighterhost‐networkintegraRon–  Allowinghosts/serviceinstancestodynamicallyupdatenetwork



SCAFFOLDaddress

ObjectID FlowID

(i)ResolveObjectIDtoaninstanceFlowLabel

(ii)RouteoninstanceFlowLabeltothedesRnaRon

Admin Prefix Object Name SS Label Host Label

(iii)SubsequentflowpacketsusesameFlowLabel

SocketID



SCAFFOLDaddress

ObjectID FlowID

Admin Prefix Object Name SS Label Host Label SocketID

SCAFFOLDaddress

DecoupledflowidenRfiers

Src FlowID Dst FlowID ObjectID Flow Labels SocketID ObjectID Flow Labels SocketID

3.  MigraRonandfailoverthroughaddressremapping

4.  Minimizevisibilityofchurnforscalability

Who Where Which conversation

ObjectID Flow Labels SocketID

SCAFFOLDaddress

ManagemigraRon/failoverthroughin‐bandaddressremapping

Src FlowID Dst FlowID

Who Where Which conversation

ObjectID Flow Labels SocketID ObjectID Flow Labels SocketID

ObjectID SS8 : 30 SocketID SS10 : 40 : 20

(i) Localend‐pointchangeslocaRon,assignednewaddress

(ii) ExisRngconnecRonssignalnewaddresstoremoteend‐points

(iii) Remotenetworkstackupdated,applicaRonunaware

Minimizevisibilityofchurnthroughsuccessiverefinement

ObjectID SS4 : 50 SocketID SS10 : 40 : 20

Where

SS1040

20

5Wide‐Area

Minimizevisibilityofchurnthroughsuccessiverefinement

SS4

SS10

ArbitrarySubnet/AddressStructure

MulRplelevelsofrefinementWide‐Area

SRC LocalHost Safari Client SS 4 50 3

DST Google YouTube Svc SS 10 40 20 5 40

20

• Scalability: –Localchurnonlyupdateslocalstate –Addressesremainhierarchical

• Infohiding:Topologynotgloballyexposed

5

Network Controller

Label Router

Label Router

Label Router

Object Router

Host

RouRng

ResoluRon

Host

B 3 A 2

Ac*on NetworkControlMsg

netlinkup join(2)

netlinkdown leave(2)

bind(fd,A) register(A,2)

close(fd) unregister(A,2)

Integratedservice‐host‐networkmanagement

Network Controller

Label Router

Label Router

Label Router

Object Router

Host

RouRng

ResoluRon

Host

B 3 A 2

Ac*on NetworkControlMsg

netlinkup join(2)

netlinkdown leave(2)

bind(fd,A) register(A,2)

close(fd) unregister(A,2)

Integratedservice‐host‐networkmanagement

Self‐configuraRon+adapRvetochurn

Using SCAFFOLD:

Network‐levelprotocols

andnetworksupport

ApplicaRon’snetworkAPI

Today(IP/BSDsockets)

fd = open();

Datagram: sendto (IP:port, data)

Stream: connect (fd, IP:port) send (fd, data);

IP:ApplicaRonseesnetwork,networkdoesn’tseeappSCAFFOLD:Networkseesapp,appdoesn’tseenetwork

SCAFFOLD

fd = open();

Unbounddatagram: sendto (objectID, data)

Bounddatagram: connect (fd, objectID) send (fd, data);

SRC B 3 0

DST A 0 0

LR 1 LR 2

Object Router

OR

DATA

DATA

Label Router 1 Label Router 2

SRC A 2 0

DST B 0 0

SRC A 2 0

DST B 3 0

ObjectID Flow Label SocketID

sendto(B)

sendto(A)

B 4

B 3

A 2

A 2

B 3

B 4

UnboundFlows

3 p1

4 p2

bind(B)join

SRC B 3 0

DST A 2 0

LR 1 LR 2

Object Router

OR

DATA

DATA


SRC A 2 0

DST B 0 0

SRC A 2 0

DST B 3 0


sendto(B)

B 4

B 3

A 2

A 2

B 3

B 4

Half‐BoundFlows

3 p1

4 p2

sendto(A,flags)bind(B)join

LR 1 LR 2

Object Router

OR


SRC A 2 765

DST B 0 0

SRC A 2 765

DST B 3 0 SRC B 3 234

DST A 2 765

SYN

SYN

SYN/ACK

ACK

SRC A 2 765

DST B 3 234

connect(B)

ConnecRonBound

joinbind(B)listen()

B 3 A 2

BoundFlows

LR 1 LR 2

Object Router

OR


SRC A 2 765

DST B 0 0

SRC A 2 765

DST B 3 0

SYN

SYN

SYN/ACK

ACK

SRC A 2 765

DST B 3 234

connect(B)

ConnecRonBound

B 3 A 2

BoundFlows

• ApplicaRonsbindonobject‐levelnames• Networkforwardsonresolvedaddresses

SRC B 3 234

DST A 2 765

joinbind(B)listen()

SRC A 2 765

DST B 3 234

Label Router 1

SupporRngMobilityandMigraRon

Label Router 3

SRC B 3 234

DST A 2 765

Object Router Label Router 2

RSYN

RSYN/ACK

ACK

LR 3

SRC B 3 234

DST A 4 765

ConnecRonMigrated

LR 1 LR 2

OR

SRC A ? 765

DST B 3 234

SRC A 4 765

DST B 3 234

B 3 A 2 A 4

Label Router 1

SupporRngFailoverandLoadShedding


LR 1 LR 2

OR A 2

FAIL

B 3

B 5

ACK

RSYN

RSYN/ACK

SRC A 2 765

DST B 3 234

SRC A 2 765

DST B 0 0

SRC A 2 765

DST B 5 529

Label Router 1

SupporRngFailoverandLoadShedding


LR 1 LR 2

OR A 2

FAIL

B 3

B 5 ACK

RSYN

RSYN/ACK

SRC A 2 765

DST B 3 234

SRC A 2 765

DST B 0 0

SRC A 2 765

DST B 5 529

• Decoupledid’senablein‐bandmigraRonandrecovery

• Flowaffinitywithoutper‐flowstateinthenetwork

Extentofchanges

 Changein‐networksupport

 Changethepacketformat

 Changesocketlayer+stack

Hdr ObjID SS | … | Host SockID

Label Router

Object Router

Network Controller

Yet:

 Canrunontopoflegacynetworks(IPandEthernet) Few/easy/nochangestoapplicaRons

Backwards Compatibility

HidephysicallocaRonfromapp

Today(IP/BSDsockets)

fd = open();

Datagram: sendto (IP:port, data)

Stream: connect (fd, IP:port) send (fd, data);

SCAFFOLD

fd = open();

Unbounddatagram: sendto (objectID, data)

Bounddatagram: connect (fd, objectID) send (fd, data);

CurrentapplicaRons–iperf,TFTP,PowerDNS

SCAFFOLDnetworkstack

Network interfaces

Application Scafd IPC

user

kernel

Network interfaces

Application

Scafd IPpackets

LinuxsocketsinterfacePacketsocket

OperaRngacrosslegacynetworks

SS4

SS10

ArbitrarySubnet/AddressStructure

Wide‐Area

SRC LocalHost Safari Client SS 4 50 3

DST Google YouTube Svc SS 10 40 20 5

4020

5

Label Router

Label Router

Label Router

Label Router

Label Router

Label Router

(Anycasted)IPAddress/Prefix

1.1.1.1 2.2.2.2

3.3.3.3 1.1/16

1.1.1/24 1.1.1.1

RouRngoverlegacynetworks

Ethernet

IPv4

TransportPort:16bobjID

Addr:8bSS|8bHost|16bsock

Ethernet

IPv4

SCAFFOLD

1.1.1.1


2.2.2.2

Current InDevelopment

In‐Networksupport

Object Router

Label Router

ModifiedOpenFlowsoiwareswitchforproporRonalsplitrouRng/resoluRon

‐ NOXapplicaRon:topology,host,objectmanagementNetwork

Controller

‐Network

Controller

Label Router

Label Router

Label Router

Object Router

Host Host

“Evaluation”

Demos

•  LoadShedding:– Callclose()onconnecRons– SubsequentpacketsgetFAIL,thenreconnect

•  Clientmobility

TFTPtransferwithClientMobility

ClientLeaves ClientReconnects(RSYN)

TFTPtransferwithFailover

Server1(FAIL) Server2(FAIL)

<100msblip

Currentthroughput

CurrentimplementaRonisbothuser/kernelspace.Ongoingdevelopmenttoeither/or.

Service‐centricnetworking

•  Moderatevision:Cannetworksupportaidself‐configuraRonforreplicatedservices?

•  Bigvision:Should“service‐centricnetworking”becomethenewthinwaistofInternet?

SCAFFOLDrethinks:1.  NamingexposedtonetworkandapplicaRons2.  Extentofhost‐networkintegraRon3.  Roleofdumb/statelessnetworkvs.end‐hosts

Service‐centricnetworkingwithSCAFFOLD

MichaelJ.Freedman

PrincetonUniversity

withMatveyArye,PremGopalan,StevenKo,

ErikNordstrom,JenRexford,andDavidShue

LatencyofAPIcalls

Networkvs.stacklatency

RelatedWork

NewArch i3 LNA DONA LISP HIP CCN SCAFFOLD

Paradigm Object Object Object Host Host Content Object

Layer 3O 4 3/4 3 4 3/4 3/4

Anycast Hash Res Prox No No Mcast Res

Resolution DHT EB Routed EB Rdz DDiff SRefine

Migration Yes Yes Yes* Yes Yes Yes* Yes

Failover Yes Yes Yes No No Yes Yes

RelatedWork

SCAFFOLD SPAIN PortLand VL2

Topology Arbitrary Arbitrary Fat-tree Fat-tree

Multipath Any Many ECMP ECMP

Migration Yes Yes* Yes* Yes*

Failover Yes No No No

Traffic Engineering Arbitrary Oblivious Oblivious Oblivious

Server Selection Yes No* No* No*

Use CoTS? No Yes No Yes

End-host Mod Yes Yes No Yes

service‐centric networking with scaffold...principles of scaffold 1. service‐level naming...

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