Xenrelay: An Efficient Data Transmitting Approach for Tracing Guest - PowerPoint PPT Presentation

Xenrelay: An Efficient Data Transmitting Approach for Tracing Guest Domain Hai Jin, We nzhi Cao, Pingpe ng Yuan, Xia Xie Cluste r and Gr id Computing L ab Se r vic e s Computing T e c hnique and Syste m L ab Huazhong Unive r sity of Sc ie nc e & T e c hnology 430074, Wuhan, China

Contents  Intr oduc tion  Re late d wor k  Xe nr e lay De sign and imple me ntation  E xpe r ime ntal r e sults  E xample of Xe nr e lay’s Value  Conc lusion

Introduction  Wide spr e ad vir tualization utilization motivate s de e pe r inve stigation of the pe r for manc e implic ations of vir tualization.  T r ac e analysis is an impor tant te c hnology  De signe r s of tr ac e tool r unning in vir tualization e nvir onme nt has to c onside r :  E a c h Doma in ha s its own a ddre ss spa c e  Sma ll size d tra c e da ta a nd fre que nt tra c e e ve nts  tra c e da ta be ha ndle d in use r spa c e

Introduction  Xe nr e lay  tra nsfe rs la rg e a mounts of da ta from the g ue st doma in ke rne l to the privile g e d doma in use r- spa c e  Sta tic sha re d me mory a nd two ma pping me thods  A non- notific a tion me c ha nism

Related work  Se ve r al pe r for manc e tools ar e imple me nte d in Xe n  Xe noprof  a syste m- wide statistic al pr ofiling toolkit  Xe nMon  pe r for manc e monitor ing tool  Xe nMon c olle c ts e ve nt log with Xe ntr ac e  Xe nr e lay is base d on r e layfs

Related work  Shar e d me mor y buffe r s  Xe nSoc ke t  Xwa y  Xe nL oop  T hose appr oac he s fall shor t of pr oviding tr ac e data tr ansmission  More hype rc a ll, more ove rhe a ds  He a d a nd othe r da ta for pa c king da ta  tra c e tool should not re ly on subsyste m

Xenrelay Overview  Main issue of Xe nr e lay  c re a te a c ha nne l throug h thre e la ye rs  c ontrol the da ta tra nsmission without loc k a nd notific a tion  Xe nr e lay c ontains:  re la y c ha nne l  API

Xenrelay Overview

Design and implementation  T r ansmitting at the high spe e d  Channe l de sign  c ha nne l buffe rs, buffe r position struc ture , c ha nne l informa tion struc ture  c ha nne l buffe r is a produc e r- c onsume r c irc ula r buffe r  bloc ks until the tra nsa c tion is c omple te  multiple xe d I/ O a nd Poll()

Design and implementation  Channe l imple me ntation  Alloc a te hig h- orde r a ddre ss  Ma p no- c onsiste d pa g e s into c onsiste d pa g e s  a g g re g a te buffe r po sitio n str uc tur e into a me mory pa g e  a ssig ns a n e xplic it size to da ta ite ms  Channe l bootstr ap and te ar down  Xe nStore me c ha nism

Design and implementation  Data r e lay  Doe s not split da ta  Doe s not pa rse the da ta Channel buffer Padding fill the buffer

Discussion  Ope r ation se que nc e  Ope n - > Conne c t - > Write - > Re a d - > Disc onne c t - > Close  Ope n - > Write - > Conne c t - > Re a d  be safe  e asy to make data ove r flow  Close - > Disc onne c t  me mor y le ak in gue st domain

Discussion  Data ove r flow  write fa ste r tha n re a d  suspe nds writing a nd c a use loss of ne w da ta  Re lay file  only the da ta in the e nd of file is va lid

Experimental testbed  E xpe r ime nt se tup  A se rve r- c la ss ma c hine  two Inte l Xe on E 5310 CPUs (1.6 GHz and four c or e s CPUs)  4GB Me mor y  500GB SAT A disk (r otation spe e d is 7200r ps)  Xe n ve rsion 3.3.1 a nd linux ke rne l ve rsion 2.6.18_X64  E a c h g ue st doma in ha s 1 VCPU, 512MB me mory a nd 10GB disk ima g e

Experimental testbed  Data tr ansmission sc e nar ios  Ne tfront- Ne tba c k  Xe nL oop  ne tpe r f’s T CP_ST RE AM te st  Xe nre la y  Move a fixe d size of data in r e lay c hanne l fr om DomU to Dom0 r e pe ate dly  100MB data in total

Experimental results  T hr oughput VS. me ssage size  In Xe nre la y, re a ding me ssa g e size = writing me ssa g e size

Experimental results  T hr oughput VS. r e ading me ssage size  writing me ssa g e size = 2 6 byte s  re a ding me ssa g e size >= writing me ssa g e size

Applications of Xenrelay (1)  Use Xe nr e lay to c r e ate a bloc k tr ac e toolkit  In g ue st doma in ke rne l, tra c e s I/ O e ve nts a nd use s Xe nre la y to tra nsfe r it  In privile g e d doma in ke rne l, tra c e s I/ O e ve nts a nd use s re la yfs to tra nsfe r it  T r ac e point  T r ac e data  de vic e numbe r, the e ve nt time sta mp, the sta rt se c tor numbe r, the numbe r of ha ndle bloc k, the e ve nt type a nd the ope ra tion type

U-Q2D : generic_make_request to elv_next_request U-T : elv_next_request to 0-T generic_make_request in dom0 0-Q2D : generic_make_request in dom0 to elv_next_request 0-D2C : block device U-Q2D handling request 0-T : blkback returning blkfront U-T 0-Q2D 0-D2C 19

Applications of Xenrelay (2)  e valuate typic al c ombinations of the I/ O sc he dule r s  Gue st Doma in Sc he dule T e st  Change gue st domain’s Sc he dule  F ix dr ive r domain’s Sc he dule and use Noop sc he dule  Drive r Doma in Sc he dule T e st  Change dr ive r domain’s Sc he dule  F ix gue st domain’s Sc he dule and use Noop sc he dule  A single 100MB file was r e ad

Applications of Xenrelay (3)  Re sult of tr ac ing  Gue st doma in sc he dule te st Noop schedule AS schedule U-Q2D : generic_make_request to elv_next_request U-T : elv_next_request to generic_make_request in dom0 0-Q2D : generic_make_request in dom0 to elv_next_request 0-D2C : block device handling request 0-T : blkback returning blkfront CFQ schedule

Applications of Xenrelay (4)  Re sult of tr ac ing – Dr ive r domain sc he dule te st Noop schedule AS schedule CFQ schedule

Applications of Xenrelay (5) • Me rg e b lo c k numb e r a nd size – Gue st do ma in sc he dule te st

Applications of Xenrelay (6) • Me rg e b lo c k numb e r a nd size – Driver do ma in sc he dule te st

Conclusion  Xe nr e lay is a unifie d, e ffic ie nt, and simple me c hanism for tr ansfe r r ing data  Xe nr e lay pr ovide s suppor ts for use r s who tr ac e subsyste ms to r e c or d and r e lay data

Thank you! Questions ?