Cloud Storage: File Hosting and Synchronisation 2.0 - Vis

11Cloud Storage: File Hostingand Synchronisation 2.0Matthias Geel – The Rainmaker«One Cloud to rule them all,One Cloud to find them,One Cloud to bring them alland in the database bind them»- Lord of the Resources(Un)fortunately, we are not quite there yet,but the cloud(s) are everywhere. For those ofyou who have managed to remain oblivious tothe cloud hype, here the most important pointsin a nutshell. Similar to other buzzwords such asWeb 2.0 and HTML 5, the “Cloud” is merely anumbrella term used to describe a diverse rangeof technologies, architectures and approachesthat are closely related to the world of distributedcomputing, clusters and grids. It is actuallyvery simple. Connect a few computers to a clusterand perform some voodoo that allows you toadd and remove computers at will. Add a layerthat allows you to automagically (sic!) distributethe workload of running applications over thephysical hardware. Voilà, scalable infrastructure.Offer a web interface to access those applications.Boom! Cloud computing. Add an array ofstorage devices that can be extended at runtime.Boom! Cloud storage. Virtualizeyour infrastructure so that youcan sell storage and computingresources in manageable pieces.Boom! Cloud infrastructure provider.Buy, rent or host your own cloudinfrastructure and provide a usefulservice on top of it. Boom! Cloudservice provider. It is that simple.In this article however, we focus on a particulartype of cloud service, namely cloud storagesolutions for end-users. These services basicallycombine file hosting and synchronisation withcloud storage. So who are those cloud storageproviders and what can they offer us?The CompetitorsThe area of cloud storage services has generatedquite some attention recently with severalmajor vendors having overhauled their servicesin the last couple of months. While we canchoose from dozens of cloud storage providerstoday, this article concentrates on the three majorplayers: Dropbox, Microsoft's Skydrive andGoogle Drive.Dropbox, Inc. is a startup company foundedin 2007 by Drew Houston and Arash Ferdowsi,two former MIT students. Accordingto Dropbox, the service iscurrently being used by over 50million people, making them oneof the largest competitors in thebusiness of cloud storage. Microsoftwas also part of the game earlyon and made their file hosting

12solution Microsoft SkyDrive available in mostcountries in spring 2008. While the service wasinitially only accessible as a web application, Microsofthas just released desktop applicationsfor Windows and Mac OS X in April 2012 to allowthe synchronisation of files across devices. Interestingly,Google only recently entered the marketwith its own product Google Drive in April2012. It is basically an extension of Google Docsand it stands to reason that the two productswill be merged at some point.The PromisesCloud storage services aimto provide effective solutionsto synchronise personal resources(e.g. documents,photos, music, arbitrary filesetc.) and/or personal settings(e.g. application preferences,browser history, save games etc.) across manydevices, to access personal data from anywhereand to easily share data with friends, co-workersand the world.Platform IntegrationA crucial feature of any cloud storage solutionis how well the client applications integratethemselves with the underlying platform. Dropbox,SkyDrive and Google Drive offer desktopapplications for Microsoft Windows and Mac OSX that integrates with the file system in someway. But desktop integration can also be takena step further by exploiting various extensionmechanisms the underlying operating systemsoffer. Microsoft Windows for example allows applicationsto register so-called Windows ShellExtensions handlers that hook into many facilitiesprovided by the Windows Shell. Using thosehooks, the desktop versions can offer a tighterintegration with the Windows platform by extendingthe context menu with custom entries,providing icon overlays to indicate the synchronisationstatus or by adding custom propertysheets to display service-specific properties. OnMac OS X, the clients integrate with the Finderapplication.The synchronisation itself is automaticallycarried out by a background service anddoes not involve any user interaction.For that reason, the desktop applicationsrely on the operating systemto be notified when files are beingcreated, changed or deletedin order to propagatethose changes to the cloudstorage service.In contrast, files are usuallynot automatically synchronisedon mobile platforms, mainly due to storageconstraints of those devices and also to limitthe bandwidth needed by the cloud storageapplication. Instead, the users have to manuallyselect the files they want to download andstore offline. As a result, users might not alwaysbe aware of the latest version of a file they havedownloaded earlier.Privacy and Security ConcernsBefore you start using a cloud storage service,you should ask yourself a few questions.First, who can access the data? Well, the cloudstorage vendors mentioned in this article canand do access your uploaded data, but insistto do so only to provide you with the service.Moreover, since those companies are locatedin the United States and therefore required tocomply with their law and regulations (includ-

13ing the DMCA Act), they may be forced to discloseyour data to US law enforcement agencies.The most effective way to prevent that is to followMicrosoft advice as written in their servicesagreement: “If you don't agree, don't use theservice. Thanks.” However, a slightly more pragmaticapproach might be to use an additionaltool like TrueCrypt to encrypt the files locallybefore they are being uploaded.Second, and equally important, is the questionof who owns the data? At least Dropboxand SkyDrive clearly state in their respectiveservice agreements that “you retain full ownershipto your stuff ” (Dropbox) and that “we don'tclaim ownership of the content you provide onthe service” (Microsoft). However, the situationwith Google Drive is a little bit more complex.After they unified their terms of services and privacypolicies in March 2012, the same rules alsoapply to Google Drive. Not surprisingly, thosepolicies are formulated in a very broad sense. Onthe one hand, “you retain ownership of any intellectualproperty rights”, whereas on the otherhand “you give Google a worldwide license touse, host, store, reproduce, modify, create derivativeworks, communicate, publish, publiclyperform, publicly display and distribute suchcontent.” However, both Dropbox and SkyDrivehave similar terms thatbasically give them theright to use your contentto the extent necessaryto provide the service.As with all terms of service and privacy policies,these statements are subject to interpretationand there have been several heated debatesabout what these statements allow theservice provider to do. In any case, it is advisableto read the corresponding terms of service andprivacy policy before deciding whether to usea particular cloud storage service. Luckily, mostof them are rather short and there has been atrend to use a language which can be understoodwithout a law degree.Open Challenges and OpportunitiesOne immediate problem is interoperability.Since there is no common interface for consumer-orientedcloud storage services, each vendorhas to offer its own client applications for allsupported platforms. As a consequence, it is currentlynot possible to share data from one servicewith another, other than manually copyingthe files back and forth. A related challenge is thequestion of how cloud storage services interactwith third-party applications. On the desktop,the situation is straightforward. Modern operatingsystems abstract the individual file systemsby providing a single API to access the data in afile system agnostic way. It is therefore able offerfacilities such as common file open and filesave dialogs that can be used by all applicationsbuilt on top of that operating system. And sincethe cloud storage applications integrate withthe file systems, they can be used immediatelyby all existing desktop applications. However,such a layer is completely missing in the currentarchitecture of theweb. Instead, the prevalentpractice is, that third-partyweb applications need touse a vendor-specific APIfor every service they want to connect to. Onepossible solution might be the development ofa meta cloud service that abstracts the concretecloud storage services from the actual applicationsand mediates all request through a unifiedAPI.

14Another interesting question is also whethercloud storage solutions can partly solve theproblem of “information fragmentation”. Informationfragmentation describes the fact thatwe use an increasing number of different devices,applications and services to create, shareand distribute personal information. Whetherwe upload a video on Facebook, edit images onthe go using our tablet, use Google Docs to createdocuments or use our smartphone to take apicture, more and more personal data is spreadacross several different devices and shared withnumerous online services. This makes it increasinglydifficult for people to keep track of theirpersonal information and to be able to controlwho can access which resource. It is thereforelikely that we will see a consolidation of serviceproviders and applications in the future. A fewsigns of that development are already noticeabletoday with Google starting to consolidateand interconnect their services and Facebookexpanding their portfolio with the latest acquisitionof Instagram and a partnership with Spotify.But the journey has just begun and the onecloud to rule them all does not exist yet. Thereare still plenty of challenges to be solved and alot of opportunities that await you, my fellowstudent. Take them and become rich. That is theplan.AnzeigeIcherzeugeEnergie.Von Windpark bis Fitnesscenter: Als Mitarbeitende/r der BKW-Gruppe fliesst Ihre Energie an vielen Orten. Und mit klimafreundlichem Strom aus Wasser, Wind, Sonne, Kernkraft und Biomasse lassen Sie täglich mehr als eine Million Menschendaran teil haben – unterstützt von 2’800 kompetenten Kolleginnen und Kollegen.Wir entwickeln und realisieren die Energieinfrastruktur von heute und morgen. Bei Ihrem Berufseinstieg in der BKW entdeckenSie Ihr eigenes Energiepotenzial und werden zum Fachspezialisten und Projektprofi, zum Beispiel als Teil unseresEngagements in der Windkraft. Für junge Ingenieurinnen und Ingenieure gibt es bei uns viel zu tun! Bewerben Sie sichjetzt – Informationen und Einstiegsmöglichkeiten finden Sie auf der zentralen Stellenbörse unserer Webseite:www.bkw-fmb.ch/karriere