WebFund 2013F Lecture 16

The audio from the lecture given on November 13, 2013 is here.

Notes

• Control flow graph
  • graph representation of program structure
  • you should know how things move in your program
    • graph is weird for web applications
      • no main => event driven
      • distributed
        • control flow goes between browser and one or more servers
      • RPC (RemoteProcedureCall)
        • sometimes when making a call? Actually making a call on something on the network
        • RPC's have fundamental security problems
        • always call by value (pass number along)
      • SOAP
        • effort to do RPC over the web
        • Problems?
          • Based on XML
            • very verbose
            • SOAP protocols based on XML are VERY verbose
      • REST
        • GET, POST, etc
• Databases
  • don't want to store everything just in a text file
    • multiple files is a pain
  • associative arrays are easier to get access to
  • concurrency
    • I want to change data structures all over the place
      • allow for concurrent updates without corrupting entire thing
  • durability
    • can change values incrementally
  • We will be using MongoDB
    • “document store”
      • it's like you are storing a collection of word documents
      • allows to to incrementally update parts of the document without corrupting everything
      • transactions
        • making changes to multiple durable data structures
          • changes are always consistent
            • all should happen or none should happen
            • atomic commits
        • documents are basically JSON objects