Hey all, I''m not exactly a networking guru, but I''m learning more every day. And it seems to me the technology behind something like Half-Life''s Client / Server architecture really wouldn''t be much different from an MMORPG''s Client / Server architecture. Is the only difference the systems they''re designed to run on? Where as Half-Life will only support 32 max players because its target server is anyone with a decent connection and MMORPGs will support 1000s of players because they have uber-machines and uber-connections? I''m just curious is all =)

While MMORPG servers tend to have higher specifications, the server software tends to be very different. For the most part, MMORPG servers tend to be clustered; that is to say that for a given game world more than one machine will actually handle the load. For example, the first iteration of the UO system used four machines to handle each shard. (There''s an urban legend about a guy who managed to crash a shard by walking back and forth between server boundaries non-stop.) The fact that the machines are clustered leads to differences in code simply for handing players (and connections) back and forth between different servers. Add in database support as well as the fact that more calculations are handled server-side (clients are less trusted) and the differences add up.

There are of course differences between the design for a multiplayer game and a massive multiplayer game. If you want to support 100.000 users your design must be different. It''s not just Ueber machines as you call them. To scale a game that has a 32 user max to 32.000 concurrent users you''d have to have 1.000 servers, not a realistic option.

The Korean MMORPG Lineage 2 got 130.000 subscribers in its first week. Lineage 1 has three million subscribers and 300.000 concurrent users.

Basically in a multiplayer shooter the client must be updated about 10 times per second, or the game becomes useless. A MMORPG could get by with updates only every few seconds. The client would predict movement, handle eg. display of the inventory, maps etc. locally without requiring the server to send a complete list/map every time. You should be able to disconnect the network cable and reconnect 15 seconds later and keep on playing in the meantime, although you probably cannot attack, pick up, chat etc. and NPC''s would be frozen. But you would be able to walk.

You don't need (edit)REAL(end edit) clusters for an MMORPG. Very few of them (if any) use any kind of actual clustering. They don't even need high-end server hardware for the most part. You might put 50 cheap single CPU pentiums with 1GB of RAM hooked up to some storage array. Other than that, nothing out of the ordinary except for the big fat pipe you need for bandwidth.

There is no magic to making massively multiplayer games. The simpler the software and hardware setup, the more stable and scalable it is likely to be. If I recall, EverQuest zone servers run on PIII 500s with 512MB of RAM. You could run a seamless world using similar low end hardware. I believe Dark Age of Camelot uses dual processor systems, but I don't think you get your moneys worth out of it. (2 processor systems tend to be more than twice the price, with less than twice the performance increase)

(edit)
The design changes aren't as much in software as they are in creative design requirements. Most MMORPGs do not require real-time health/status updates like a shooter does. If you shield the technical stuff from the player with good creative design, you can get away with a lot of 'cheating' in the technical design.
(end edit)

Oh well, have fun, good luck.

f

[edited by - fingh on December 26, 2003 10:32:48 PM]

[edited by - fingh on December 26, 2003 10:34:28 PM]