In-Network Management. Rolf Stadler. Stockholm, Sweden

Transcription

1 To help protect your prvacy, owerot preveted ths exteral pcture from beg automatcally dowloaded. To dowload ad dsplay ths pcture, clck Optos the Message Bar, ad the clck Eable exteral cotet. I-Network Maagemet Rolf Stadler KTH Royal Isttute of Techology Stockholm, Swede 19th Iteratoal Coferece o Computer Commucato ad Networks ICCCN 2010 August 2 5, 2010, Zurch, Swtzerlad

2 Outle Nt Network kmaagemet I-Network Maagemet Case Study: Real-tme Motorg Wll t happe?

3 Maagemet Systems aalyze aalyze Maagemet System act observe act observe Network Maaged System Server Cluster

4 What s Network Maagemet? Network Maagemet refers to the actvtes, methods, procedures, ad tools that perta to the operato, admstrato, mateace ad provsog of etworked systems A. Clemm, Maagemet of Networks ad Networked Systems volves the followg fve tasks CAS. ault Maagemet Cofgurato Maagemet Accoutg Maagemet & User Admstrato erformace Maagemet Securty Maagemet defto from the telecom commuty, late 1980s. 4

5 Network Maagemet aradgms Maagemet Autoomc Maagemet OO Maagemet Maagemet olces MIB Maagemet Iformato Base TMN Telecommucato Maagemet Network 5

6 Network Maagemet Cofereces Yearly coferece sprg: IEEE/II IM Iteratoal Symposum o Itegrated Network Maagemet IEEE/II NOMS Network Operatos ad Maagemet Symposum Sgle-track evet fall: IEEE DSOM Dstrbuted Systems Operato ad Maagemet IEEE CNSM Coferece o Network ad Servce Maagemet

7 Network Maagemet Jourals IEEE Trasactos o Network ad Servce Maagemet TNSM sce 2007 Joural of Network ad Servce Maagemet JNSM sce 1993, publshed by Sprger IEEE Commucatos Magaze Seres o Network ad Servce Maagemet twce a year

8 Nt Network kmaagemet I-Network Maagemet Case Study: Real-tme Motorg Wll t happe?

9 Today s Maagemet Systems for Tradtoal Network Techologes aalyze Maagemet System act observe Maagemet tellgece outsde maaged system. Clear separato betwee maagemet system ad maaged system, by desg. Maaged System

10 Today s Maagemet Systems for Tradtoal Network Techologes 2 aalyze Maagemet System Maaged System Motorg ad cofgurato, geerally CAS fuctos, performed o a per-devce bass. Successful for - small umber of odes < low rate of chage - log reacto cycles <1 sec

11 I-Network Maagemet: Key Idea polces drectos exceptos otfcatos aradgm Shft Reduce teractos betwee maagemet ad maaged systems lace maagemet fuctos sde the maaged systems Delegate tasks to a self-orgazg maagemet plae Eablg cocepts: embeddg, decetralzato, t self-orgazato

12 I-Network Maagemet: Egeerg Aspects polces exceptos otfcatos self-orgazg maagemet plae maagemet ode Maagemet odes wth processg capabltes sde devce, blade, applace eer teracto through eghborhood cocept overlayoverlay Maagemet fuctos execute as dstrbuted algorthms o overlay ygraph; ca be voked o each ode; are part of a self-orgazg maagemet plae 12

13 The Drvers for I-Network Maagemet Lack of maagemet frastructure eergy-costrat evromet ---sesor etworks, MANETs, vehcular etworks Avodg bottleecks large-scale systems ---access etworks, data ceters, maaged ed-devces Shorte reacto tme -dyamc evromets -msso-crtcal etworks State ca be estmated ad acted upo sde the etwork - ault maagemet - Routg, resource allocato 13

14 ault Resoluto Tmes Excessve OS messages force US Telco to brg dow parts of ATM etwork: 26 hrs Outage several Mllo US$ Impact Re esoluto Tm me Bad redudacy mplemetato forces traffc through a 64kbt udersea cable: 4 hrs Outage several Mllo Impact Source: Csco LS black hole ssue forces Arle to groud all plaes: 20 mutes Outage Lack of memory a swtch several Mllo US$ Impact causes Itermtted outages o tradg floor Impact: 1 Mllo per 1 mute Iadequate QoS o GgE lk bookstore mpacts trasactos per secod: Mllos of US$ secods

15 Sde Thought: A Revval of Network rogrammg? Itatves : Actve Networkg: actve packets wth state ad code, customzed packet processg o routers; pursued by Iteret commuty rogrammable Networks: focus o terfaces, e.g., for coecto maagemet, QoS; pursued by broadbad commuty, stadardzato IEEE 1520 Impact: specalzed techologes programmable layer 4/7 swtches, tellget frewalls, lmted dustral mpact o adopto by major maufacturers; operators ad provders valued operatoal safety over flexblty 15

16 Nt Network kmaagemets I-Network Maagemet Case Study: Real-tme Motorg Wll t happe?

17 Motorg Aggregates Aggregate tw 1 t,..., w t Aggregato fuctos,w,., w j,...,w j,., w,... w l t w k t w t Local varables w j t Sum w 1 1,,...,, w, Average, Max, Quatle Dstctve Elemets {w 1,..., w } Heavy htters { } Hstogram {w 1,..., w }

18 Decetralzed Motorg Aggregate tw 1 t,..., w t t Aggregato rotocol w l t w t w k t w j t

19 Challeges Estmato of etwork states, stuato awareess, threshold detecto. Uderstadg ad cotrollg trade-offs betwee accuracy, overhead, robustess, depedecy o the system sze, dyamcty, to buld tuable ad self-tug systems Uderstadg the sematcs of mgt operatos o a large system uder chage Uderstadg the mpact of estmato errors o the effect of maagemet decsos

20 A-GA: rotocol desg goals rovde a maagemet applcato wth a cotuous estmate of a aggregate sum of local values for a gve accuracy. Tuable trade-off: accuracy vs. overhead -lowest overhead for a gve accuracy objectve Dyamc y adaptato to chages -chages to local values, topology, falures Scalablty -overhead crease wth system sze s sublear A. Gozalez reto, R. Stadler: A-GA: A Adaptve rotocol for Cotuous Network Motorg wth Accuracy Objectves, IEEE Trasactos o Network ad Servce Maagemet TNSM, Vol. 4, No. 1, Jue 2007 D. Jurca, R. Stadler, H-GA: Estmatg Hstograms of Local Varables wth Accuracy Objectves for Dstrbuted Real-Tme Motorg, IEEE Trasactos o Network ad Servce Maagemet TNSM, Vol. 7, No. 2, Jue

21 I-Network Aggregato usg Spag Trees Maagemet Stato artal Aggregate Local varable Global Aggregate 25 Root SumtSumw 1 t,..., w t hyscal Node Aggregatg Node Leaf Node w 7 t 21

22 A-GA: rotocol desg prcples Creatg ad matag spag tree -Spag tree o maagemet overlay -BS tree based o self-stablzg stablzg protocol by Dolev, Israel, Mora 90 Icremetal -etwork aggregato g o spag tree - Aggregate computed bottom-up o odes of tree -Result avalable at root ode lterg updates -Reduce protocol overhead by flterg updates whle observg error objectve -Compute flters usg a dstrbuted heurstc S. Dolev, A. Israel, ad S. Mora, Self-stablzato of dyamc systems assumg oly read/wrte atomcty. ACM Symposum o rcples of Dstrbuted Computg ODC '90, Quebec Cty, Quebec, Caada, August,

23 Local Adaptve lters Local varable or partal aggregate g Last update value lter wdth lter Exceeded: 1 Trggers a update to paret 2 lter s shfted tme Local flter o a ode Cotrols the maagemet overhead by flterg updates Drops updates wth small chage to partal aggregate erodcally adapts to the dyamcs of etwork evromet 23

24 roblem ormalzato d flter wdths to motor aggregate for a gve accuracy objectve, wth mmal overhead Overhead: max processg load ω over all maagemet processes Accuracy objectve: average error Mmze { } Max ω s.t. E[ E root ] ε percetle error Mmze Max { ω } Max ω st s.t. p E root >γ θ maxmum error Mmze { } Max ω s.t. E root κ 24

25 A Dstrbuted Heurstc The global problem s mapped oto a local problem for each ode { } Mmze ω π Max s.t. π E E out ε Attempts to mmze the maxmum processg load over all odes by mmzg the load wth each ode s eghborhood lter computato: decetralzed ad asychroous Each ode depedetly rus a cotrol cycle: every τ secods { request model varables from chldre compute ew flters ad accuracy objectves for chldre } compute model varables for local ode 25

26 A Stochastc Model for the Motorg rocess Model based o dscrete-tme Markov chas It relates for each ode - the error of ts partal aggregate - evoluto of the partal aggregate - the rate of updates seds - the wdth of the local l flter It permts to compute for each ode - the dstrbuto of estmato error - the protocol overhead Updates to paret G Node state λ S out E out Update rate Step szes Estmato Error lter wdth ω Update rate processg load Updates from chldre S E Step szes Estmato Error 26

27 Stochastc Model: leaf ode otherwse X X j Estmatg step sze MLE Evoluto of local varable X Trasto Matrx. 0 otherwse < < + 0 0, j j j j X X j X t > + + s z s G z X d s s z Step Sze otherwse s z d G z X s S d d d z out Estmato Error Maagemet O erhead 0 otherwse. 0 1 S λ out G E 27 Maagemet Overhead 0 1 out S λ

28 Stochastc Model: aggregatg ode Step Sze: > + s k s G k S s Iput Output Δ Δ c c c c out s S s S γ > + s k d G k S s k s G k S s S d d d k s k out 0 Estmato Error: c out E E out G E E + c γ otherwse 0 c λ ω Maagemet Overhead: c γ 0 1 Δ S λ. c γ λ ω 0 1 Δ out S λ Trasto Matrx: 0, j j j j S t 28 Trasto Matrx: < < + 0 j j S S t

29 Model-based Motorg Error Objectve Estmato Error Estmato model varables Optmzato roblem Stochastc Model of Motorg rocess 0,035 0,03 0,025 0,02 0,015 0,01 0, Overhead 3 2,5 Updates/sec 2 1,5 1 0,5 0 ode 1 ode 2 ode 3 ode 4 ode 5 ode 6 ode 7 Step Szes lter Wdths Measured Estmated Aggregate Estmato x t Measuremets local varables Tree-based aggregato

30 Tradeoff: Accuracy vs Overhead ε 0 ARC Upda ates/sec ε 2 ε 5 T m A-GA ε 10 ε 15 ε Avg Error Overhead decreases mootocally Overhead depeds o the chages of the aggregate, ot o ts value. A-GA outperforms a rate-cotrol scheme ARC 30

31 Robustess mato Error Est Tme 175 Max xmum Load U Updates/sec Node A fals Ed of Traset Tme 175 Estmato error: several spkes durg sub-secod traset perod Overhead: sgle peak wth a log traset 31

32 A-GA rototype Lab testbed at KTH 16 motorg odes 16 Csco 2600 Seres routers Smartbts 6000 traffc geerator A-GA mplemeted Java Maagemet Stato Aggregato o Tree Node 1 Node 2 Node 3 Node 4 Node 5 Node 6 Node 7 hyscal Network 32

33 rototype: Maagemet Stato Iterface Select Aggregato ucto Select Accuracy Objectve Select Root Node Evoluto of the Aggregate True Value ad A-GA Estmato Overhead Dstrbuto ad Evoluto Show Aggregato Tree Real-tme Estmato of Error Dstrbuto ad Trade-off 33

34 rototype: Error Estmato by A-GA vs Actual Error 0, ,08 Measured Error Error Estmated by A-GA 0,06 0,04 0,02 Absolute Avg Error 0, Error 30 Accurate estmato of the error dstrbuto Maxmum error >> average error oe order of magtude 34

35 Gossp vs. Tree-based Aggregato

36 Computg aggregates through gosspg ush Syopses [Kempe et al. 03] The protocol computes AVERAGE of the local varables x. After each roud a ew estmate of the aggregate s computed as s /w. Expoetal covergece o coected graphs rotocol Ivarats: s x,, r, r, w r r Roud 0 { 1. s x ; 2. w 1; 3. sed s, to self } w Roud r + 1 { * * 1. Let { sw, } be all pars set to durg roud r * 2. s s w ; l l l l l * w l 3. choose shares α 0 for all odes j, j such that α j, j 1 4. for all j sed α * s, α * w to each j }, j, j D. Kempe, A. Dobra, ad J. Gehrke, Gossp-based computato of aggregate formato, roc. 44th Aual IEEE Symposum oudatos Computer Scece OCS, Oct

37 The G-GA protocol 5. for all j Neghbors { a. rs, j, rw, j rs, j, rw, j + rs m, rw m acks m, ackw m Roud 0 { morg : m j 1. s b. acks, j, ackw, j srs, j, srw, j + x ; 2. w 1 ; s m, w m morg : m j 3. L {} ; c. f detected_falurej { 4. for each ode j rs, 0,0. s, w s, w + rs,, rw,, j rw, j ; j j 5. for each ode j srs. rs, j, rw, j srs, j, srw, j 0,0, j, srw, j 0,0 ; 6. sed s,,0,0,0,0. L L \ j w to self; 7. for all j sed 0,0,0,0,0,0 to j } } Roud r+1 { } 1. Let M be all messages receved 6. for all j L { by durg roud r a. choose α, j 0 such that j α, j 1 2. s s m + xr, x 1, m M r ; w w m m M b. choose β, j 0 such that 3. for all j acks, j, ackw, j 0,0 j β, j 1 ad β, 0 4. L L org M c. srs, j, srw, j β, j α, s x, β, j α, w 1 d. sed α, js, α, jw, srs, j, srw, j, acks, j, ackw, j to j e. rs, rw rs + +α s, rw + α w } }, j, j, j, j, j, j

38 Accuracy vs. Overhead gossp- ad tree-based aggregato protocol GA ad G-GA 654 ode etwork GoCast overlay, coectvty 10 aggregato: AVERAGE UT trace 4 rouds/sec o falures. Wuhb, M. Dam, R. Stadler, A. Clemm Robust Motorg of Network-wde Aggregates through Gosspg, IEEE Trasactos o Network ad Servce Maagemet TNSM, Vol. 6, No. 2, Jue 2009.

39 Accuracy vs. alure Rate gossp- ad tree-based aggregato protocol GA ad G-GA 654 ode etwork GoCast overlay, coectvty 10 aggregato: AVERAGE UT trace 4 rouds/sec odes fal radomly, recover after 10 sec Tree-based aggregato outperforms gossp-based aggregato!

40 Nt Network kmaagemets I-Network Maagemet Case Study: Real-tme Motorg Wll t happe?

41 I-Network Maagemet Why t wll happe Compared to 5-10 years ago: New actors Google, Amazo, Mcrosoft, Apple New drvers data ceter etworkg, cloud computg, Advaces dstrbuted computg gossp protocols, algorthms for vrtual topologes, uderstadg protocols o dyamc topologes Eablers of etwork programmablty maufacturers Juper, Csco provde ope terfaces Opelow allows for programmable cotrol ad maagemet plaes 41