A question on system resources

[Daeftan]

There have been some great posts on read and write times, but I am interested in how the use of imbedded SQL commands use server resources when compared with the internal DB or logging.

In my particular application, I do not care how long it takes for data to be written to the DB/log/file since I do not intend to use it for any realtime purpose within the game. Nonetheless, the easiest option for me is to run NWNX4 and have it transmit data directly to a hosted mySQL server; however, if it comes at a large expensive of game server resources I am reluctant to do it. A more messy option is to have the game server log to its own DB or file and then periodically pass the file off server and parse it into the DB.

Does anyone have any helpful thoughts about this?

[Gryphyn]

[Grumalg]

Gryphon's advice is correct and excellent for having a very light ram footprint. This approach will be useful to those who want to run more than one instance of nw server on a single machine.

But if ram isn't an issue to you, you can get better performance with larger caches set up in MySQL. Especially when the DB engine runs for long periods.

If your data and index caches can hold the entire data and indexes for your DB it will typically already have data/index present in cache and thus run at ram speeds and access the HD rarely. Even when writing to the DB, it will write to the cache and return to you and do the actually HD write when it feels it has spare time (which will be most of the time at the light loads a PW represents to MySQL).

If the DB engine is rarely shut down and the computer rarely rebooted you will be essentially running the DB in a ramdisk after it's been running a while. Data/index space in the caches is reused by flushing things that haven't been used for the longest time when caches fill up. Thus, when the caches are big enough, nothing ever gets flushed from them. It does have to rebuild the contents of the caches from the HD over time as things are first referenced each time the DB engine is restarted though...

I suspect that many people useing NWN2/NWNX4 will be wanting 3gb or more ram just so they can get to the 2gb process limit in NWN2 and still have room for the OS. Since the OS doesn't chew a gb, that will leave a goodly amount of space for big caches if you want to use them.

--- Grumalg ---

[Daeftan]

Thanks guys. Very useful comments.

Speaking of I/O - it is my impression that this is the major bottle neck in a semi-full to full server. I feel like I can appreciate this even in my home test network where I run one NWN2 server and then two game clients on different machines. After the server load, the processor demands of the server seem low, while the network traffic seems high.

Does any one have hard numbers on the data traffic of the server-to-client as the number of players/DMs scale up?

[Gryphyn]