[mannyv]

In most data architectures the DB is only the backing store, because no matter how fast your database is it's going to be slower than RAM.

Once you start caring about the performance the second thing you do is stick a cache layer of one sort or another in front of the database; the first thing should be making sure you have the correct indexes.

In any case, it sounds like a distributed cache problem. I wonder if you could just abuse redis for your game backend?

[justinlloyd]

You can use redis or memcached, but every MMO or online game I've been involved with, unless it was a "web game", has eschewed those for the most part. The game server maintains the state, knows all the objects in the universe, or at least its portion of the universe, and is responsible for retrieving and updating those objects. Even redis and memcached would be considered slow by comparison. Those game objects/world objects/MOBs may eventually be pushed out to a key-store server, but generally are not. The only portion of the database on any MMO I've worked on that has cared about "proper indexes" has been the area dealing with account retrieval. Traditional databases, at least on the non-web MMOs I've been involved with, when it comes to game state, are not normally used. RDBMS are used for boring things like account management, customer management, and so forth. Our database on the current (non-web) MMO uses a few more web technologies than I have in the past for this particular problem, but once the shard is loaded, and the user is connected, it is back to tradition, for the most part.

[machiaweliczny]

What protocols are used to stream updates to client? Or it’s simulation on client and state dump on fails?

[kylestlb]

may help to read the article, redis is mentioned