Resorce Maagemet Model of Data Storage Systems Oreted o Clod Comptg Elea Kaa, Yry Korolev Sat Petersbrg Electrotechcal Uversty "LETI" (ETU), Sat Petersbrg, Rssa {leaaa, yryg}@gmalcom Abstract Ths artcle represets a resorce maagemet model of data storage systems oreted o Clod Comptg The model presets a sgle terface provdg a ser wth a optmal resorce set o the bass of the specfed reqremets I INTRODUCTION At the preset tme oe of IT areas, called Clod Comptg (CC), s beg achevg a pea of t's evolto It cased by evolto of spport techologes le teret, telecommcatos, data store systems, formato protecto systems ad tegrated platforms - they became so matre, that ca provde relable fodato for global formato systems bldg ad o the other had are able to garatee creasg eeds relablty, moblty ad effcecy of formato frastrctre The qatty of Clod provders s creasg At the same tme the qatty of the terfaces gve by provders for access to resorces of the clod s growg as well I spte of the accessblty of ope terfaces, there s o possblty to get the resorces from varos Clod sg the form terface of teracto There was a dea to create a possblty of the fed access a certa terface to Clod resorces whch wold help all spplers to provde the resorces wth the mmm rs ad garateed stablty It wold allow clets to move stacs of appedces from oe clod to aother, avodg solato ad ths to ct dow expeses Specfcty of sg data store systems for CC dffers from both tradtoal server systems ad data ceters It meas, that ds capacty CC systems s provded o call for some tme ad the retred Reqred data store relablty, eergy cosmpto, data repar speed case of a crash, access rate ad some other parameters are ma effcecy characterstcs of sch systems The artcle presets a resorce maagemet model of data storage systems whch ma target s esrg effectve vrtal resorces formg ad provdg a access to them from ay termal The drect clsters teracto both betwee each other ad wth vrtal resorces wll be descrbed frther The clsters cosst of physcal hosts The developed model advatage s the possblty to provde a sgle resorces access terface whch esres the reqred Q-factors II PROBLEM DEFINITION I ths artcle the ma object of cosderato s a clod strctre allowg ser to retreve access to the vrtal resorces o demad Let s say the ser to the exteral evromet eeds to retreve resorces wth pre-defed qalty parameters ad the cost ot ---------------------------------------------------------------------- 54 ----------------------------------------------------------------------
more tha the pre-defed oe The tas cossts the sgle terface descrpto whch s redered by a resorce access clod strctre III RESOURCE MANAGEMENT MODEL DESCRIPTION It s cosdered that the term "clod" came from tradtoal graphc depcto of the World Wde Web as a small clod Sch a pctre s sed to demostrate a etwor topology that has a Iteret segmet [2] Coseqetly a clod ca be maged as a set of dfferet types objects coected wth each other ad formg a arbtrary topology A object ca cosst of oe or several odes Clod strctre s fractal becase both separate odes ad embedded clods ca be cosdered as clod elemets Sch a strctre s preseted graphcally the fg1: Fg1 Cocept strctre Represetg a clod as some objects wth detcal characterstcs ad the terface of access wold allow s to abstract from the teral devce of these objects ad represet each of them as a blac box The ser does ot have ecessty to th of how the resorce wth certa qalty characterstcs has bee provded What s mportat s the fact of the resorce allocato I order to have a opportty to provde a fed access terface, a specal part for teracto both wth a ser ad other objects shold be detached Let s call t a resorce maager (Clod Maager) The resorce maager (CM) provdes a ser wth 3 terfaces of object resorces retrevg: 1 Bloc (bloc resorces provso) Bloced resorce presetato Ds emlato s sed ad reqests are exected throgh, for stace, SCSI protocol 2 Object (DB or BLOB) Resorce s provded as a object 3 Fle (NFS, CIFS) Resorced are preseted as a fle system based o POSIX stadards The resorce maager gves access to operatos targeted at resorces retrevg wth certa qalty rates The operatos ca be splt to the followg grops: 1 Qc access to resorces 2 Operatos for provdg relablty 3 Qc formato recovery 4 Eergy cosmpto redcto (E) targeted at the cost optmzato Clod Maager has ecessary meas of resorce maagemet whch sally cosst of the processor wth eogh memory ad the blt- operatg system CM ses the same geeral terfaces of bloc level as sal IDE / SCSI dss, represetg the eclosed composte objects as vrtal dss ---------------------------------------------------------------------- 55 ----------------------------------------------------------------------
The vrtal ds s the geeralzed abstracto of the data storage devce He behaves as a sal bloc devce, bt has o correspodg physcal ds Istead, t s coected to exstg bloc devces Coecto of the vrtal ds meas that all pt-otpt qres wll be drected to a vrtal ds whch wll redrect them to the basc devces The cocept of vrtal dss allows to spport a wde rage of dverse platforms, ad also gves the chace to rese the exstg fle systems ad techology of operatg systems Clod Maager ca be costrcted o the bass of exstg systems wth lttle chages OS Here, the operatos of fle system over sal fles wll be ept M coects the servce formato provded to the ser wth pt/coclso operatos va the vrtal address bloc of clster The vrtal address bloc s a bloc of addresses otsde of possbltes of physcal clster The dea of sage of vrtal address blocs s based o the followg observato: as a rle, the potetal of bloc devces s mch less tha the maxmm vale whch the operatg system ca spport Ths, t s possble to se the addtoal addresses of blocs otsde of capacty of physcal clster as vrtal addresses of blocs [5] Commo ser ad clod strctre tercoecto scheme s preseted fg 2 Fg 2 Strctre tercoecto scheme The model cossts of two ma ettes: 1 U a ser who eed to be provded wth the resorces wth the garateed qalty 2 Clod objects cldg CM ad maaged resorces These resorces ca be formed by a certa clster or jst the same composte object Whe the ser U reqests the partclar resorce, he eeds certa ds capacty ad certa qalty rates sch as resorce provso speed S, relablty R ad recovery tme Tr Aother mportat qalty rate s resorce provso cost The ma tas of the CM s the optmzato of cost fcto to provde resorces wth gve characterstcs P f(v, S, R, T, r E) The parameters of the optmzato fcto are jst those dcators of qalty whch the ser eeds Gve: odes cot the clster, m - ested clods cot So, let's bld a optmzato fcto for dstrbto data storage heterogeeos evromet: 1 The volme provded by object V = V m O(V ) = 0 = 0 + + [R, R, 0, where V R 0 + volme of a sgle physcal host the clster; V ] rage of volmes for all objects belog to the embedded clod; O overhead cased by a formato dstrbto; V se-reqested resorces ---------------------------------------------------------------------- 56 ----------------------------------------------------------------------
V m S, S + S max, where S 0 R = 0 V + + access speed to the formato of a sgle physcal ode () the clster; S [R,R ], 0 rage of veloctes for all objects belog to the ested clod; S K access speed to the embedded clod or physcal clster; S max maxmm object's speed 2 The speed resorce allocato = 1 S = + S m 3 Relablty of resorce allocato R = 1 ( 1 R ), where 0 R 1 probablty of = 0 = 0 falre of a sgle physcal ode () a clster () T = max, where 4 The data recovery tme r T r + Tr R recovery tme of a sgle physcal ode () a clster () Recovery tme s especally mportat at the orgazato of bsess processes where stablty of system ca deped o the refsal of data allocato 5 Eergy cosmed by the object E = E O, where m = 0 = 0 E R + eergy cosmpto of tae separately physcal ode the clster belog to both ma ad embedded clods O beeft from sg algorthms for power maagemet optmzato Eergy s a vale that fleces bascally oly o the cost of resorces allocato The ma tas of the model s recepto of the form relable terface of resorces allocato by creato the Clod Maager The tas of Clod Maager s to choose the set of odes a clod (each of whch has characterstcs V, S, T r, R, E ) whch ca meet reqremets of the ser V, S, T r, R, E Ths problem ca be redced to a mltdmesoal apsac problem [1]: There are hosts, wth weghts: [V1,, V ] N volme; [S1,, S ] N speed;,, T ] N respose tme; [Tr1 r [R1,, R ] N relablty; [E1,, E ] N eergy; ad tlzato cost [p1,, p ] N ; ad ser reqremets V, S, T r, R, E The challege s to fd a set of odes that the volme set s ot less tha the amot reqested by ser, the access speed s ot less tha reqred, provde the ecessary respose tme, relablty ad eergy cosmpto V V, S S,Tr Tr,R R,E E, P m I addto, problems of optmal decso search appear O (V ) I other words, oe of ma goals s to fd a optmal algorthm of ds resorces maagemet (algorthms of formato dstrbto ad dplcato) The other goal s to fd a optmal algorthm of eergy maagemet O I case whe t s eeded to maage hge amots of data wth dfferet reqremets, metadata ca help to express sch reqremets sch a way that clod maagers cold dfferetate ther processg order to meet ser reqremets I case of sg moble ---------------------------------------------------------------------- 57 ----------------------------------------------------------------------
storage techology, t s eeded to stadardze metadata wtch wll be terpreted by a clod maager le resorce characterstcs Qalty level, ser costrats, geographcal ad etwor posto shold be clded to the stadard Usg of metadata wll lead to creasg of relablty level ad eve devce, storg reqred resorce, damaged, t s possble to fd the bacp of t after aalyss of metadata stored o other devces IV CONCLUSION Hgh qalty ad hgh resorce avalablty are ma reqremets, wtch ser eeds from Clod-provders Fractal resorce maagemet model for data store systems s preseted Some of t's ma characterstcs are formalzed The fed access terface provded by Clod Maager wll gve a opportty to coect clods wth each other ad, ths, get fed access to all clods from all clod-provders Ftre model evolto sggests developmet of ds resorces maagemet algorthms cldg dsc memory reservato procedres, power spply maagemet for eergy cosmpto mmzato, formato dstrbto ad dplcato algorthms for the effectve data access provso from ay access pot REFERENCES [1] S Arora, D Karger, ad M Karps Polyomal Tme Approxmato Schemes for Dese Istaces of N P-Hard Problems Proceedgs of the Twety Seveth Aal Symposm o the Theory of Comptg, ACM, 1995 [2] M Armbrst, A Fox, R Grffth, etc, Above the Clods: A Bereley Vew of Clod Comptg Electrcal Egeerg ad Compter Sceces Uversty of Calfora at Bereley, 2009 [3] S Mcrosystems, Itrodcto to Clod Comptg Archtectre, 2009 [4] J Strass, C Lesews-Laas, J Mazzola Palsa Devce Trasparecy: a New Model for Moble StorageMassachsetts Isttte of Techology 2009 [5] Xaoa Ma, A L Narasmha Reddy, MVSS: Mlt-Vew Storage System Departmet of Electrcal Egeerg Texas ---------------------------------------------------------------------- 58 ----------------------------------------------------------------------