Just Cause 2 Multiplayer: Behind the scenes with gaming's greatest hack

Would be great to see some articles on their technical approach, I assume they have used techniques to reach those scales based upon the fact the average pair of players are too far away from each other to be visible

Re: Just Cause 2 Multiplayer: Behind the scenes with gaming's greatest hack

#5

Post by heretohelp » Mon, Sep 17, 2012, 1:49 PM UTC

robert00700 wrote: post #4

Would be great to see some articles on their technical approach, I assume they have used techniques to reach those scales based upon the fact the average pair of players are too far away from each other to be visible

I can just about guarantee you they're abusing lensing to make it viable. (Not that that's a bad thing, WoW is the same way.)

More impressive is the fact that the server can support 1,800 concurrent gaming-grade low latency clients regardless of lensing. That's really hard to do. These guys should be getting paid to implement low-latency protocols and servers.

Re: Just Cause 2 Multiplayer: Behind the scenes with gaming's greatest hack

#6

Post by rjzzleep » Mon, Sep 17, 2012, 2:10 PM UTC

robert00700 wrote: post #4

Would be great to see some articles on their technical approach, I assume they have used techniques to reach those scales based upon the fact the average pair of players are too far away from each other to be visible

i second that, immediately went to check if the source code is available, but sadly nothing.

Re: Just Cause 2 Multiplayer: Behind the scenes with gaming's greatest hack

#7

Post by incant » Mon, Sep 17, 2012, 2:17 PM UTC

About that 1800 players number. Based on posts by one of the developers, their server doesn't do any sort of calculation:

> Our server is basically 'dumb', it doesn't do anything in the sorts of processing bullet trajectory, player line of sight or any hit detection at all.

http://www.jc-mp.com/forums/index.php/topic,638.msg4783.html...

Unlike other games which run a full simulation on the server-side, their server (I presume) mostly routes messages between players. This means that the server trusts the client, which is rather poor design for a competitive multiplayer game. Once this is released, players will probably prefer a cheat-free game to a large-scale one.

This is, nevertheless, a fantastic mod. But these people have not yet solved the c10k-equivalent problem for massively multiplayer games.

Re: Just Cause 2 Multiplayer: Behind the scenes with gaming's greatest hack

#8

Post by joezydeco » Mon, Sep 17, 2012, 2:18 PM UTC

I can't stop cracking up watching these videos. It's like a 3D visualization of Reddit or 4chan.

"...in the last test players were killed 223,704 times, averaging out at 1.29 untimely ends per second."

Re: Just Cause 2 Multiplayer: Behind the scenes with gaming's greatest hack

#9

Post by jjrumi » Mon, Sep 17, 2012, 2:31 PM UTC

incant wrote: post #7

About that 1800 players number. Based on posts by one of the developers, their server doesn't do any sort of calculation: > Our server is basically 'dumb', it doesn't do anything in the sorts of processing bullet trajectory, player line of sight or any hit detection at all. http://www.jc-mp.com/forums/index.php/topic,638.msg4783.html... Unlike other games which run a full simulation on the server-side, their server (…

Could you elaborate on the c10k-equivalent problem for massively multiplayer games ?

Re: Just Cause 2 Multiplayer: Behind the scenes with gaming's greatest hack

#10

Post by Geee » Mon, Sep 17, 2012, 2:40 PM UTC

incant wrote: post #7

About that 1800 players number. Based on posts by one of the developers, their server doesn't do any sort of calculation: > Our server is basically 'dumb', it doesn't do anything in the sorts of processing bullet trajectory, player line of sight or any hit detection at all. http://www.jc-mp.com/forums/index.php/topic,638.msg4783.html... Unlike other games which run a full simulation on the server-side, their server (…

They could verify those things on other clients, instead of on the server. I think that's typical for pure P2P multiplayer games. They could use something like - every player sending their version of 'what happened' to the server which then decides the proper outcome.

Btw, is it required to simulate everything on the server side? I know it is the conventional way to prevent cheating, but how about just randomly sampling some of the actions to detect cheating, and ban that user?