WebFund 2013F Lecture 19

The audio from the lecture given on November 25, 2013 is available here.

Notes

==Assignment 4 remarks

Before insert, do a lookup
1. If there, you have the document and edit that
Search for a special room called “start”
1. Start is not a room, it’s a room pointer
2. Can put description of a room in there
3. Could have everything linked to the start room
  1. Have all rooms exit to start
  2. Title won’t be start
JavaScript string replace
1. Don’t use a for-loop
  1. There are nice string manipulation routines in JavaScript
TA’s will be using their own custom database to test code
Look up how to do file uploads
1. Might do this in tutorial
2. Don’t have to do string checking, just have to check objects to make sure all fields are there and they aren’t undefined
3. Do all the exits refer to a room that actually exists?
  1. Not super important to do
4. Each room has name, title, description exits, has a start room
  1. Can say valid
Have to validate the data structure
1. Have to make sure you don’t import garbage
Don’t have to do this with AJAX

- To get style points, probably going to have to do something nice
  - Probably don’t want to have to press submit a million times
Always time costs when you distribute a system
How’s it going to fail?
- Anything from a database is expensive
Want a static webserver for front end
- Incoming requests first go through here, if it can handle it, it will hand it off and respond
- If it can’t, it will send it back
Gets don’t change server state, posts do
Gets can be cached
CDN
- Content Distribution Network
- Some combination between static servers and caching
Reading is never a problem
Searches are easy
Writes are what slow you down
- Cannot be automatically replicated
- Changed the state of part of your database, essentially your data structure
- This is what limits database scalability
Fred Brooks