After you have assimilated the full knowledge of that highly relevant article, you’re ready to move on to http://sol.gfxile.net/mmorpg.html.

If you want a system where a server going down means nothing goes down then you should be paying more for your developers+operations than your software because NO system has that out of a box. Even if it did, without users, you’re burning cash. That’s really not an option anymore for the next say, 5 years. If you *happen* to have a lot of funding then you’re 1 in a million and I’d recommend taking advantage of that and again, spending more on your developers, marketing, and game quality than on architecture. Architecture and systems designers (data layer) EXPECT critical scaling problem with operations because that’s their job; the people who will make a game worth being bought don’t work that way.

I think anyone who’s starting an MMO w/an rdbms knows it’ll be replaced and if they don’t then I doubt they’ll end up here.

Also, considering I have yet to register the full version (probably when I go “alpha extreme” next month) I’ve gotten great support from the developers in their forums on the freebie 20 user license.

There’s no way I’d be as far as I am today with this game if I had to write all that myself. I personally think SmartFox 2.0 is going to be a killer update.

Anyway–I’ll probably launch the public alpha in a month….but then again I’ve been saying that for a year now. :) Thank you SmartFox!

who knows it helps your MMO

Eric says that he’s getting ease of development out of a DB and he’s thought about the tradeoffs, which is all I can ask for! My rant’s targeted at people who just assume a DB is the way to go.

Project Darkstar is several years from being useful for development. It promises to eventually simplify multi-sub-server development, but I think it’s quite a way from being really helpful in that arena. (I’ll talk about more in a while, probably.) I am really happy to see it exist, but regardless of who you talk to, the .9 releases available now are single-server only, meaning their key feature is missing. You’d be better off with SmartFoxServer, just for its niceties like friends lists, IP bans, and other minutia.

My big concern is not throughput. It is spikes of latency and outright deadlock. WoW had an issue where mining would lock the user up, and they would have to log out. What I heard was it was a DB deadlock or a transaction on the row containing that rock that never completed. By being DB-centric and relying on the DB’s transactionality, the operation could never complete. Took a long time before they fixed it. You would also see pretty significant delays when scrolling through items the auction house.

Another example: What happens when you have to do DB maintenance? With a non-DB centric solution, you could keep running the game and only risk losing some game time if something crashed, as opposed to losing revenue (assuming you charge per minute), or ticking off the community if you closed the game.

I can think lots of reasons to not rely on the DB for synchronization and state transmission. I understand that Eric feels it is a matter of money and a continuum of “quality”, not a digital must/must-not. I can respect that. Just be aware of the risks/costs/consequences. It is nice that Eric or Sandra are the game designer. They “get” the trade off, and can design around it. I’m designing for those less tolerant, and who have money.

DB clustering (MySQL Cluster in my case) and ram based caching (Cluster does it, plus you can layer on more for each of the server machines in the non-DB cluster, either Hibernates 1st and 2nd level cache or memcached or what have you) makes a hell of a screaming machine.

As for 1 millisecond response times – lol. What do you think we’re making here, an MMOFPS? There’s very, VERY few MMOs that require that kind of speed.

As for 5000 users, no problem. Cluster will do 100k replicated transactions per second with around 5-10ms of latency with 4 nodes in the cluster. You want more, add more machines. There’s an upper limit of course, but it’s high.

Anyway, I’m not just some DB guy spouting. I’ve done many, many years of game work as well. Almost 2 decades worth now.