Lecture Notes in Computer Science 6462 CommencedPublicationin1973 FoundingandFormerSeriesEditors: GerhardGoos,JurisHartmanis,andJanvanLeeuwen EditorialBoard DavidHutchison LancasterUniversity,UK TakeoKanade CarnegieMellonUniversity,Pittsburgh,PA,USA JosefKittler UniversityofSurrey,Guildford,UK JonM.Kleinberg CornellUniversity,Ithaca,NY,USA AlfredKobsa UniversityofCalifornia,Irvine,CA,USA FriedemannMattern ETHZurich,Switzerland JohnC.Mitchell StanfordUniversity,CA,USA MoniNaor WeizmannInstituteofScience,Rehovot,Israel OscarNierstrasz UniversityofBern,Switzerland C.PanduRangan IndianInstituteofTechnology,Madras,India BernhardSteffen TUDortmundUniversity,Germany MadhuSudan MicrosoftResearch,Cambridge,MA,USA DemetriTerzopoulos UniversityofCalifornia,LosAngeles,CA,USA DougTygar UniversityofCalifornia,Berkeley,CA,USA GerhardWeikum MaxPlanckInstituteforInformatics,Saarbruecken,Germany Kai Sachs Ilia Petrov Pablo Guerrero (Eds.) From Active Data Management to Event-Based Systems and More Papers in Honor of Alejandro Buchmann on the Occasion of His 60th Birthday 1 3 VolumeEditors KaiSachs IliaPetrov PabloGuerrero TechnischeUniversitätDarmstadt,FBInformatik/DVS Hochschulstraße10,64289Darmstadt,Germany E-mail:[email protected],[email protected] [email protected] The illustration appearing on the cover of this book is the work of Jean Bacon. PermissiontoreproducethisillustrationhasbeenobtainedfromJeanBacon. LibraryofCongressControlNumber:2010938789 CRSubjectClassification(1998):C.2,H.4,D.2,H.3,I.2,C.2.4 LNCSSublibrary:SL3–InformationSystemsandApplication,incl.Internet/Web andHCI ISSN 0302-9743 ISBN-10 3-642-17225-3SpringerBerlinHeidelbergNewYork ISBN-13 978-3-642-17225-0SpringerBerlinHeidelbergNewYork Thisworkissubjecttocopyright.Allrightsarereserved,whetherthewholeorpartofthematerialis concerned,specificallytherightsoftranslation,reprinting,re-useofillustrations,recitation,broadcasting, reproductiononmicrofilmsorinanyotherway,andstorageindatabanks.Duplicationofthispublication orpartsthereofispermittedonlyundertheprovisionsoftheGermanCopyrightLawofSeptember9,1965, initscurrentversion,andpermissionforusemustalwaysbeobtainedfromSpringer.Violationsareliable toprosecutionundertheGermanCopyrightLaw. springer.com ©Springer-VerlagBerlinHeidelberg2010 PrintedinGermany Typesetting:Camera-readybyauthor,dataconversionbyScientificPublishingServices,Chennai,India Printedonacid-freepaper 06/3180 Alejandro Buchmann Preface “I think there is something wrong with your arithmetic ... Alex and I are about the same age, and he and I cannot be getting close to 60.” Hector Garcia-Molina Datamanagementhasevolvedovertheyearsfrombeingstrictlyassociatedwith database systems, through active databases, to being a topic that has grown beyond the scope of a single field encompassing multiple aspects: distributed systems, event-driven systems, and peer-to-peer and streaming systems. The presentcollectionofworks,sheddinglightonvariousfacetsofdatamanagement, is dedicated to Prof. Alejandro Buchmann on the occasion of his 60th birthday. His scientific path looks back on more than 30 years of successful academic life andhighimpactresearch.Withthis bookwe celebrateProf.Buchmann’svision and achievements. The works presented here cover many different topics: database systems, event-based systems, distributed systems, peer-to-peer systems, etc. All these are areas in which Prof. Buchmann and his group were active and provided relevant researchcontributions over the years. The area of data management, streams and XML spans contributions from Theo H¨arder et al. on XML processing and key concepts implemented in XTC; from M. Tamer O¨zsu et al. on mining streaming data; from Thomas Kudraß on activedatabasesystems;andfromFrischbierandPetrovondataintensivecloud applications. The field of event processing is covered through contributions from many leading researchers such as K. Mani Chandy on extending the boundaries of sense-and-respond applications to the Web and the Cloud; from Jean Bacon, Ken Moody et al. on spatio-temporal composite event languages; from Opher Etzionet al.onspatialperspectivesineventprocessing;andfromGeroMu¨hl et al. offering insights on underlying design principles implemented in Rebeca. The fields of quality of service and real-time systems are represented by contributions from Krithi Ramamritham et al. on safety partition kernel for integratedreal-timesystems;fromAnnikaHinzeetal.onanonymousmobileser- vicecollaboration;andfromDimkaKarastoyanovaonscientificexperimentsand services. The area of peer-to-peer concepts and systems contains contributions from Gerhard Weikum offering an overview and in-depth insights on peer-to-peer web search; from Max Lehn et al. on benchmarking peer-to-peer systems; and from Christof Leng et al. on building an SQL query processor for peer-to-peer networks. VIII Preface The field ofpervasive computing is coveredby interesting contributionsfrom FriedemannMatternetal.onInternetofThingsandRFID;fromBettinaKemme at al. around group communication for mobile devices through SMSs; and from Daniel Jacobi et al. on an approach to declaratively constraining the nodes participating in a sensor network query. Another active researcharea of Prof.Buchmann is performance engineering, whichisrepresentedbyapaperintroducingthenovelQPME2.0toolbySamuel Kounevetal.anda workloadcharacterizationforeventnotificationmiddleware from Stefan Appel et al. We are grateful to all those world-class researchers, colleagues and friends who, with their works, joined us in honoring a truly remarkable figure: as a visionary and a distinguished personality, as a professor and a leading faculty member,asanacademicpeer andfellowresearcher,as supervisorandmentor— Alex Buchmann. September 2010 Kai Sachs Ilia Petrov Pablo Guerrero Joint Celebration of the 60th Birthday of Alejandro P. Buchmann, Sorin A. Huss, and Christoph Walther on November 19th, 2010 Honourable Colleague, Dear Alex, Let me first send my congratulations to you as well as to Sorin Huss and Christoph Walther. You jointly celebrate your 60th birthdays this year. I wish you all the best for your future work at TU Darmstadt! Alex, we have survived many battles and wars in the overlap time of our periods of servicein the department’s headquarters.In the former period, I was yourDeputyStudies,inthelatterperiod,youwereoneofmyDeputies General. I remember well our meetings in your office (yours is more comfortable than mine),wherewefrequentlydebatedthemosturgentchallengesoftheday.These meetingsalwaystookmuchmoretimethanplanned(iftheywereplannedatall). And each time, I left your office a bit smarter than before, and more confident that we would eventually cope with all of the trouble. And we did. A few months ago,you retired; no, not from your position as professor,but fromthattreadmilltheycall“Dekanat”.Soyoumademoretimeforresearch.By the way,research:yourbreadthandwealthofresearchinterests,whichyoupur- sue together with yourresearchgroup,are impressing.So is yoursocialnetwork in science and beyond. You three guys are true institutions of the department (I am tempted to speak of dinosaurs, however, in an absolutely positive sense). You have seen colleaguescomeandgo.Due toyourexperienceandyourlong time ofservicein the department, you have become critical nodes of the department’s corporate memory network. Your experience has been decisive during many discussions, typically (yet not exclusively) for the better. Ishouldmentionthateachofyouthreeguysisequippedwithaspecific kind of spirit. Your humorous comments, always to the point, made many meetings amongstcolleaguesreallyenjoyablefortheaudience(well,themeetingchairdid notalwaysenjoythem,butthat’sfine). Youhavealwayscombinedpassionwith reason, spirit with analysis, vision with rationality. X Preface Onbehalfofthecolleagues,thedepartment,andTUDarmstadt,Ihopethat youthreeguyscontinueto haveagreattime togetherwith allofusandaneven longer chain of success stories than ever. Happy Birthday! September 2010 Karsten Weihe Dean of the Department of Computer Science, TU Darmstadt Laudation for Alejandro Buchmann I was delighted to be asked to write a laudation for my colleague Alejandro Buchmann.Notbecausewearewellacquaintedorhaveworkedtogetherclosely, neither is the case,regrettably,but becausehe is,for me,a perfectexample ofa scientistcomingfromabroadandbecomingsuccessfullyintegratedherewithout losing his own cultural identity, and in the process enriching our culture and making a lasting contribution to scientific and academic life in this country. AlejandroBuchmannbeganhisacademiccareerinhisnativecountryMexico, studyingnotcomputerscience,inthosedaysthatwasnotyetpossibleinMexico, but chemistry! He worked briefly as a chemist for Hoechst, but then decided to continue his studies, obtaining his Master of Science degree from the University of Texas in Austin. But, like other engineers, he soon became fascinated with our blossoming computersciencediscipline.AftersuccessfullycompletinghisdoctorateinAustin, Texas, he worked mainly in the field of computer science, which is where his major accomplishments lie. And for TU Darmstadt it was definitely a happy development when he accepted the offer of a C4 professorshipthere in 1991. I do not wish, at this point, to go into his numerous academic and scientific achievementsandthemanyhonoursaccordedhim.Hisuniversitycolleaguesand partners can do a much better job of that. Instead, I would like to draw atten- tion to the wayhe has usedhis internationalnetworkof contacts and his innate capacityforenthusiasmto buildandconsolidatecloseties andcooperationwith his home country and other countries across Latin America. We all know that buildinginternationaltiesandcooperationrequiresagreatdealofcommitment, and in particular a proper appreciation of the many and sometimes consider- able differences between countries in terms of education and training. And who has been able to make better use of such knowledge and understanding for the countries of Latin America than Alejandro Buchmann? To my regret, I have personally only once had the opportunity to witness him “in action” here: committed, emotional, eminently competent and highly professional! In this role Alejandro Buchmann has become an ambassador for Germancomputerscience,andforhisachievementsinthiscapacitytheGerman computer science community and its representative body, the Gesellschaft fu¨r Informatik (GI), is greatly indebted to him.