Developers Corner

A lot of the performance problems in MMOs appear DB related, is there a particular favorite DB in use for MMOs? id assumed it would be Oracle but looking at Funcoms site AoC would appear to be using SQL server. Anyone any experience of the DB side of MMOs?

I’m currently working as DBA so I’m really curious to know that too.
Oracle RAC seems to be a good choice, but… you never know. There’s also IBM db2.

/bump

Yes same, I have over 16 years oracle experience and it would seem such an obvious choice for something like an MMO.

My professional experience is in web programming using PHP and MySQL, which is also my choice for my MORG.

MYSQL may be ok for a prototype but in terms of scaleability, performance, backuo and recovery its a non starter for something like an MMO. How many concurrent accounts/users can you manage on MYSQL?

Originally posted by Thoth-Amon

MYSQL may be ok for a prototype but in terms of scaleability, performance, backuo and recovery its a non starter for something like an MMO. How many concurrent accounts/users can you manage on MYSQL?

Its good enough for my game. It will handle my server needs of 1024 simultaneous players. 

I never use MySQL servers, I cane be mistaking though, but it doesn't seem to work that good on Linux... And everyone knows (or should know!) that Windows is by no means stable enough to host anything but websites.

Apache all the way for me. :}

Well, I'm using sqlite for my prototype database :) For production I have been using postgresql. For me the backend doesn't matter all that much. For most mmorpg's it's not really the database that limits connections though, I would say the application layer is the real bottleneck. Especially if you are going to have fancy things like player/player collision detection. Mysql seems to be good enough for second life, which honestly has more complex database needs than most games. Although scale-wise obviously WoW has the biggest demands on its database. Google has such large demands that they don't use SQL at all, using their own persisted filesystem, with very structured canned queries. It might be worth looking into similar alternatives.

If you've got the cash of course, you might as well shop the bigger options, a la oracle et all. I think a lot of games use Microsoft sql server, as loath as I would be to use a microsoft product on the server side. But they get by with it :)

For most games I feel that sql is a bit wasted. It is mostly used as a way to save stuff in case the server fails or has to be taken down, with little use while the game is running, which hopefully is what your server spends the most time doing. Even the fastest access to the database is not going to be as fast as caching everything in memory. You want to use the database wisely, hitting it as infrequently as possible, for instance grabbing a lot of data with a single select statement instead of grabbing things one at a time.

i think WoW is running on ORACLE RACs.

I would go for oracle also - i just love stored procedures :D

I always found it impressive that DAoC ran (or still runs) on MySQL.

Excerpt from the Gamasutra Post Mortem by Matt Firor:

"5. The joys of open source software and stability. Long ago, during the development of our early titles, we decided to use Linux wherever possible as our server back-end OS, and we kept to this same practice when creating Dark Age of Camelot. We have extensive Linux experience in-house, and it made sense for us to stay with a platform that we knew could handle the task and also was, well, free.

Because running Camelot would require a considerable amount of data management, we initially planned on using Oracle to store account and character information. However, Oracle's quoted license fee of more than $900,000 quickly removed them from contention. Once we got over our shock and amusement at Oracle's pricing, we turned to a Linux-based freeware solution, MySQL, to manage Camelot's data storage, which so far has worked admirably.

Everyone developing games should at least investigate open source solutions for their servers. It's saved us a pile of money and has been stable and reliable. In fact, prior to Camelot's launch, it was axiomatic that MMORPGs were unstable and prone to crashing during their first month or so. From the outset, we were determined to buck this trend. We co-located our servers directly at UUNET, on the network backbone, which ensured a wide network pipe to the Internet. With this Internet connection, we can increase our band-width with just a few hours' notice to UUNET.

With the combination of reliable server code and a stable Internet connection- all running on open source software - Camelot went live on October 9, 2001, with virtually no problems. That first night, the game went down for about an hour and a half due to a database configuration problem, but since then, the game has been remarkably solid and stable. As of this writing, it hasn't been down due to server error for more than a few minutes ever since the first night."

Source: http://www.gamasutra.com/features/20020213/firor_pfv.htm


So that's pretty impressive for what must've been MySQL 3 or earlier back then. No views, no stored procedures; all querying written on a higher tier of code.

It's additionally impressive considering Camelot Herald queried the database as well, for all the realm rank standings, keep statuses, etc.

Pretty inspiring given they dodged a million dollar invoice from Oracle and everything worked out absolutely fine.