1. 1 Vasant Tendulkar, Joe Pletcher, Ashwin Shashidharan, Ryan Snyder, Kevin Butler, William Enck 2012 Annual Computer Security Applications Conference

2. Introduction Approach overview Browser resource limitations Designing and scheduling jobs Evaluation Discussion 2

3. Pay-per-use computation EC2 Cloud-based Web browsers JavaScript executes on the server Arbitrary general-purpose computation within cloud- based browsers Browser MapReduce(BMR) Mapper.js Reducer.js 3

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5. Cloud browsers have articial limitations Mappers cannot use local storage to communicate intermediate results Bit.ly Encode URLs up to 2022 characters in length Rate-limits requests to 99 per IP address per minute Job scheduling 5

6. Benchmarks Computation Elapsed Time Memory Cloud browsers Amazon Silk Cloud Browse Opera Mini Puffin 6

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10. Map and reduce abstraction Scheduling jobs Example applications Word Count Distributed Grep Distributed Sort 10

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13. To effectively use cloud browser an URL shortening service resource Assume Input is divided into a large number of equally sized files Mapper scheduling Reducer scheduling 13

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15. Master determines M n, the number of mappers to spawn M f, the number of input files to pass to each mapper 15 Assumes f s is several times smaller than b s

16. Rate limiting of URL shortening services Bit.ly Encode URLs up to 2022 characters in length, Us = 2022 Rate-limits requests to 99 per IP address per minute, Un = 99 16

17. Application spefic bucket in bucket sort Partition in word count 17

18. Word Count http://foo.com/?word1=5&word2=7&... Distributed Grep http://foo.com/?bar1.txt=45&bar1.txt=48&bar2.txt=34 Distributed Sort TeraSort http://foo.com/?key1=file1&key2=file2&key3=file3 18

19. Experiment setup Word Count 100 most downloaded books from www.gutenberg.com/ebooks/ Distributed Grep IRC logs for the #debian channel Distributed Sort Hadoop teragen A 10 character key and an 88 character value 19

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22. Recommendations for Cloud Browser Providers Rate limits on authenticated user Enhancing BMR Using multiple cloud browser Combination of URL shortening services 22

23. THE END 23