Further Improvement-sub story needed

[Ray1988]

• use story id instead story name
  • story structure {id: str, impression: int, read:in}
• counting events will be invoke by batch
  • e.g. [{ storyid: 121212, impression:100, read: 1}, {storyid: 121311, impression: 20, read: 2} ...]
  • a user's client report the story 121212, has been show up 100 times, but only been read once. need to add up those counts.
  • We might ensure those client report will be sent at least every hour. So an offline client won't spike the read count for that day it become online
• top story mean top n story (n >=100)
• also need to record impression, impression is important, since read/impression ratio is a factor to show how good a story is.
  • need to query this counts
  • given a set of story ids, get their impression and reads. We may need to get the data in hours, days, ... or total.