Riderwood Computer Club - Advantages and Disadvantages of Cloud Computing

Transcription

1 9/16/2014 Lost in the Cloud Marvin Zelkowitz Professor Emeritus, Computer Science University of Maryland College Park, Maryland Computer Club August 2014 Riderwood Computer Club 1 Plato visits Google s headquarters You google whenever you want to know anything at all, Plato repeated, any subject, big or small. So all of knowledge is concentrated right here at the Googleplex, and those who work here are privy to all knowledge. This is so extraordinary it almost strains credulity, that knowledge could be localized in this way. Well, as you ll learn on your tour, his guide says the knowledge isn t actually at the Googleplex. This is just corporate headquarters. Where is it then? he asked. Where s the knowledge? It isn t anywhere in particular. It s in the cloud. From Plato at the Googleplex: Why Philosophy Won't Go Away by Rebecca Goldstein. Riderwood Computer Club 2 1

2 Simple answer: Cloud computing is? Connecting to some computer on the Internet, as in visiting a webpage But it is more than that. The big difference is in being large Riderwood Computer Club 3 Why large? Think of saving money? Methods: Problems with each method: Riderwood Computer Club 4 2

3 Advantages of banks Relative safety for money especially for large amounts. Legal protections on using credit cards and on bank fraud. Accessible often anywhere in world (e.g., ATMs). Piggy banks and mattresses offer none of these features. Riderwood Computer Club 5 So, cloud computing is An evolution in how we view computers and the way we access information The technology is a mixture of the Internet we have always had (Really? Only since 1990) with some new concepts The concept is still evolving for the last 4 or 5 years. We still do not know where it will end up. This is an era (Ugh! Again!) of great change. Why do I say we don t know where it will end up? Riderwood Computer Club 6 3

4 Analogy with Medicine When a treatment works, there is only 1 option: Childhood diseases amoxicillin (Ignore for now effects of disease resistant bacteria. That is another talk) When a treatment doesn t work, there are many options: Cancer surgery, radiation, chemotherapy, laetrile, reflexology, herbal medicines, alternative therapies. (Some work, Some work sometimes, some don t work at all) Same is true with computer technology Riderwood Computer Club 7 Computer models - Compilers Almost every compiler (e.g., Java, C, C++) has a similar structure Riderwood Computer Club 8 4

5 But for Cloud computing Riderwood Computer Club 9 So for cloud computing The concept is rapidly evolving No one has the right (accepted? dominant? approved?) idea of how to represent the cloud But all models have a common aspect Use the vast resources of the Internet to allow for the user to access this vast store of information and technology easily without knowing the details of its structure In order to better understand where the cloud concept came from, we need to go over the evolution of computer technology for the past 50 years in about 10 minutes Riderwood Computer Club 10 5

6 Computing 1950s Single large mainframe. User used entire machine. Hollerith (i.e., IBM) cards used for data entry Think of the big computers with spinning tape drives from old B grade Sci-Fi movies of the 50s Riderwood Computer Club 11 Computing 1960s Single large mainframe. Machine faster. Teletypewriter or CRT terminal used for data entry. Riderwood Computer Club 12 6

7 Computing Early 1970s Single large mainframe. Machine faster. Excess machine capacity. Connect multiple CRTs to a time sharing system so each user could use machine while another user waited. First use of sharing resources among multiple users. Riderwood Computer Club 13 Computing Late 1970s Cheaper minicomputers are starting to replace mainframes. Mainframes used as file backup systems for large databases. Riderwood Computer Club 14 7

8 Computing 1981 First PCs appear on scene. Standalone systems. Apple II is from 1976, IBM PC from IBM gave legitimacy to PC market. Visicalc, then Lotus 1-2-3, gave it its first killer app. Riderwood Computer Club 15 Computing Early 1980s Replace dumb terminals with PCs as smart terminals. Development of client-server model of computation. Have 3 layers of systems: PCs with data owned by user Minicomputer as central office repository and corporate programs Large mainframe offsite for large corporate databases Riderwood Computer Club 16 8

9 Client-server computing Growth of multitier systems led to concept of powerful machine providing brute computing power with local PC providing a thin client to manage presentation and data entry and output. Example: To search a 1,000,000 record database, no need to move each record to PC. Let search be conducted on mainframe with only results passed back to PC. This basic model is behind today s web browser technology. Riderwood Computer Club 17 Networking Users at one location use the resources at another location ARPANET pioneered this concept in 1970s. Private networks (e.g., Compuserve, AOL, prodigy in 1980s) Provide reliable communications by having multiple routes from source to destination; Initially needed explicit destination address. Early work (in mid-1980s) on machine independent protocols (Usenet, August 18, Archie, 2014 Veronica, Gopher) Riderwood Computer Club 18 9

10 Networking 1990s ARPANET became the Internet by mid-1980s. Network backbone now run by ISPs (Internet Service Providers). Users directly on network. First browsers and html files around (At CERN) Start of web as a commercial tool for the masses. Rapid growth of websites and URLs in early to mid-1990s. Growth and importance of search engines Altavista, Yahoo, Ask, Google, Bing, as gateways to find relevant sites. Riderwood Computer Club 19 Networking 2000 Millions of sites. Each company had a portal (specific URL) that users went to in order to access services at that site: Look up information Buy products Provide computing capabilities In only 10 years ( ) had gone from no computers to where everyone needed (or at least wanted) one. In 20 years ( ) had gone from no networking to a need for everyone to be on the net. Riderwood Computer Club 20 10

11 Networking status No real structure to Internet services Wild west mentality of using web services. Each company had its own model of computing Huge amounts of processing power and data storage Initial thoughts of how to manage these resources The cloud grew out of this turmoil Model of the Internet Pre-cloud era Cloud era Riderwood Computer Club 21 Cloud today When you go to a website, you often don t go to a specific machine. E.g., Google.com takes you to a gateway near where you are. (e.g., If in another country very hard to get to the Google search site of your home portal.) The same is true for most large organizations and popular websites What is the goal of cloud computing and where is it likely to be in the next 5-10 years? Provide a common interface for user computational needs Provide CPU and storage access User programs and user access can be distributed on Internet. No need for users to synchronize diverse machines Riderwood Computer Club 22 11

12 Resources needed by a cloud user Computer with browser. No other software needed. (Google Chromebook) Can access data and programs from anywhere in the world with any computer on the Internet. Only software needed to be updated is browser. You have no idea where the actual programs and data reside. The PC then becomes a data appliance. Use browser to access most programs. Have a few simple programs for local actions: print, some local file storage, skype Riderwood Computer Club 23 Example: Moses uses Facebook Riderwood Computer Club 24 12

13 Example: Moses uses Facebook Amazon CNN News Yahoo answers YouTube Skype telephone Google groups Google maps Twitter Google translate Craigslist Google search Facebook events Gmail Nothing beside a web browser was required to accomplish this. So why do you need a computer? Riderwood Computer Club 25 Enabling technologies What allows all this to happen? Multiple sources (smart phones, Laptops, PC, tablets) Inexpensive memory Terabytes for only a few dollars. (1.5M books, 1M songs.) Bandwidth 15 Mbps to 25 Mbps becoming standard Processing power Up to 1 teraflops on a single multicore CPU Economies of scale Thousands of CPUs in a server farm give petaflopsof performance Maintaining software No software distribution/upgrade problem Only a single version to maintain (vs. Macs, Win7, Vista, Win8, Linux, Solaris, Android, ) Inhibitors August CIA 18, 2014 of security - Confidentiality, Riderwood Computer Integrity, Club Availability 26 13

14 Economies of scale CPU speed no longer doubling every 2 years (End of Moore s Law) Instead industry has moved to multicore cpus Multicore CPUs can process up to 1 teraflops, but home machines do not know how to utilize multiple cores well. (Cannot parallelize programs to use multiple cores) But a server farm of thousands of multicore cpuscan effectively process thousands of users on the same task efficiently. Achieve much higher cpu utilization. Riderwood Computer Club 27 Security issues Trustworthiness and security are the areas that few companies have adequately addressed in their rush to jump on the cloud bandwagon. Confidentiality How do we ensure that no one else can access our data? How many credit card numbers have been stolen from various financial institutions recently? Do we want to make all of our data as vulnerable? If we store trade secrets in the cloud, can we ensure that our competitors cannot access it? Integrity Can we be sure that the data we put in is the same as the data we extract? One advantage of the cloud is that files will in general be more reliably backed up than what most users do today. Availability Can we access our data when we need it 24x7? What happens if our cloud service goes bankrupt? What assurance do we have that we can access, download or move the data to another service? Riderwood Computer Club 28 14

15 Security issue examples 1. Protecting data: Setup:You have confidential data and you receive a summons to produce that data. If you held data: You have choice to comply or go to court to contest that summons. If cloud has data: Third party cloud organization more likely to comply and less likely to contest summons. Result: You have given up some rights to try and protect your data. 2. Moving data: If you move to a new service, will you be able to move your data there as well? (e.g., recovering when moving to a new server) It is likely that much user data will move to the cloud before legal issues such as these are resolved. Riderwood Computer Club 29 Future computing Social media Communication Financial services File storage Internet Search Word processing Video Photography Games Most of these will probably be subscription services Riderwood Computer Club 30 15

16 Software as a service SaaS is a concept where web browser becomes the thin client (i.e., use of HTTP-like protocols). Services are designed around many client companies For example, TurboTax is a specific application Google drive can provide database services for multiple clients Dropbox, One drive, Google Drive, provide data storage No longer own software, but subscribe to it. Pricing usually recurring subscription. Growth of HTTPS (Secure HTTP) viewed as providing good-enough security for most applications. Riderwood Computer Club 31 Conclusions both good and bad The cloud is here and not likely to go away. Era of owning software (even though you legally only license it) may change. Growth of renting software applications. Greater stability in quality (fewer versions to maintain, backups more automatic). Security and trustworthiness not really worked out. There undoubtedly will be some colossal failures before this is resolved. Increasing ease of use for many applications. Companies selling hardware may suffer no need to continually buy new PCs if your current browser can keep up with transmission speeds. Riderwood Computer Club 32 16

17 Lost in the Cloud Marvin Zelkowitz Professor Emeritus, Computer Science University of Maryland College Park, Maryland Computer Club August 2014 Riderwood Computer Club 33 17