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The Big-O value of "friends of friends"

Pinball Wizard (161942) writes | more than 11 years ago

User Journal 6

is n^2 if I'm not mistaken(as users increase their friends by n friends, their friends of friends increases by n^2. Roughly, up until the point that you and all your friends are at the limit => 200^2 = 40,000 friends of friends) Slashdot calculates these friend of friend values many times over each page we load.

Perhaps this is the reason for the slowness. An n^2 algorithm is one of the most unscalable algorithms you can have.

Thoughts?

is n^2 if I'm not mistaken(as users increase their friends by n friends, their friends of friends increases by n^2. Roughly, up until the point that you and all your friends are at the limit => 200^2 = 40,000 friends of friends) Slashdot calculates these friend of friend values many times over each page we load.

Perhaps this is the reason for the slowness. An n^2 algorithm is one of the most unscalable algorithms you can have.

Thoughts?

6 comments

FoF (0)

Anonymous Coward | more than 11 years ago | (#5147408)

Thought: bad idea?

Thoughts? (1)

gmhowell (26755) | more than 11 years ago | (#5147621)

Yeah, CT and the gang are a bunch of fucktards. Would one meta/. story per quarter be so goddamned bad? We're doing it in journals, we do it on k5, why not just be honest and put it on the front page of /. where it belongs?

Cliff, sorry if you are reading this, but your compatriots show very little sense of community. Are there any other editors (let's not waste time pretending they are 'users') who participate in discussions?

How much will page views drop if the trolls can't game the system?

It's just more bloat. (1)

eugene ts wong (231154) | more than 11 years ago | (#5147686)

I don't appreciate seeing a bright green speck out of the corner of my eye. I want that green speck to mean that that guy is my friend. So this information really does prove to be useless. It's not so bad for that page when you want to decide to make him friend/neutral/foe. It's good to see what others think. It's useless for the regular pages. Many of these features lately have been useless. I don't understand why they would bother with these. I get the impression that there are many good unfulfilled feature requests, but they keep on making these lousy 1s.

All I see are larger pages that waste screen realestate, & take longer to load. It's all free, so I can't complain.

Most likely (1)

norwoodites (226775) | more than 11 years ago | (#5148459)

Mostly likely you cannot ever get to the limit because you end up with friends of friends being friends and such.

Re:Most likely (1)

FortKnox (169099) | more than 11 years ago | (#5150212)

Great point. It was I was going to say.

I think it would increase to a peak, then slow down and almost fall to zero because people would be adding friends that were already friends, or f-o-fs.

hmm... (2, Informative)

jeffy124 (453342) | more than 11 years ago | (#5148503)

recalculating every re-load is probably not the cause of the slowness. when they first implemented it, it did not appear to cause a slowdown.

my guess is that since people dont change friends/fans/etc very often (and that majority of users dont use the zoo or use it sparingly), they probably maintain a table for each user listing what user is to have what icons next to their usernames. If a username is not listed, use the default gray dot. only when a change gets made by a user do the tables get updated.

I think /.'s troubles (as many others have said) is due to their recent server move, where they may have less bandwidth or server capacity available.
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