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        Arimaa >> Site Discussion >> Timeouts
        
(Message started by: Fritzlein on Jan 3^rd, 2011, 2:36pm)

Title: Timeouts
Post by Fritzlein on Jan 3^rd, 2011, 2:36pm

In my last three attempts to play, my bot opponent timed out twice and I timed out once when I was disconnected and couldn't get the board to refresh. Since I have plenty of experience of better times, I'm not going anywhere, but I can imagine that a similar experience would alienate most newcomers. Can anything be done to prevent the server from overloading?

Title: Re: Timeouts
Post by DonEsteban on Jan 3^rd, 2011, 4:52pm

I experienced the same. The whole site seems sluggish today. Maybe it's just a temporary problem (I hope)?

Title: Re: Timeouts
Post by rbarreira on Jan 3^rd, 2011, 6:11pm

Opfor2009CC was using 26.6% of the server's memory when your game against it timed out.

At this moment a running instance of Clueless2008CC is using 37.9% of server memory:

http://arimaa.com/logs/20110104/00/0201

With values like these it's not hard for the server to run out of memory and start thrashing and swapping which can easily cause running programs to grind to a halt.

Title: Re: Timeouts
Post by Hippo on Jan 4^th, 2011, 1:40pm

Having bots server independent on gameroom server could help with this problem ... at least HvH games would not be interrupted by bot's behaviour. But having many players climbing the ladder would overload the bot's server as well.
So further investsments to hardware would be probably required ...

Title: Re: Timeouts
Post by omar on Jan 4^th, 2011, 6:50pm

Yes, more than CPU load the memory consumption seems to be causing the problem. I'll look into adding more memory to the server.

The bots will be disabled during the event games, so hopefully they do not cause any problems for the tournament.

Title: Re: Timeouts
Post by Fritzlein on Jan 4^th, 2011, 7:34pm

on 01/04/11 at 18:50:29, omar wrote:

The bots will be disabled during the event games, so hopefully they do not cause any problems for the tournament.

How exactly does disabling work? I am guessing that you don't interrupt HvB and BvB games that are in progress before the tournament games starts, but if so, then what happens if the server is already sluggish? If my tournament game had been scheduled yesterday, I would have had trouble even logging in to take a seat and start.

Title: Re: Timeouts
Post by omar on Jan 4^th, 2011, 11:14pm

Yes, games in progress are not disturbed. Here is how it works: 30 minutes before the start of a rated, non-postal, event game and during such a game starting of bots is disabled. Except bots rated less than 1500 are allowed to be started since they don't use much resources and only new players usually play them.

Title: Re: Timeouts
Post by Fritzlein on Jan 4^th, 2011, 11:46pm

Thanks for providing the exact details!

Title: Re: Timeouts
Post by rbarreira on Jan 5^th, 2011, 9:40am

I'm taking a guess here that some of these bots which use a lot of memory are using the same configuration that they used when they played the computer championship. At least this would explain why some bots are using a big portion of the server's memory.

Since it seems that misconfiguration of bots can lead to excessive memory usage, maybe some bot developers wouldn't mind providing an alternative configuration file for lower CPU and memory usage when they submit their bots for the computer championship, if that is at all possible for the bot in question (i.e. not as an absolute requirement for submitting a bot)

In this way, Omar could simply replace the bot's configuration file with this one when setting up the bots for public play after the WCC / Arimaa Challenge games are over.

Personally I wouldn't mind doing that, assuming my intution is correct here. Maybe Omar could suggest an approximate value to shoot for in this configuration. Something like 1 CPU and memory consumption at around 100-200 MB for example.

Title: Re: Timeouts
Post by omar on Jan 5^th, 2011, 11:46am

GnoBot and clueless are coded to require about 1 GB of RAM. If bots provide a configuration parameter to allow lowering this it would be great. Actually clueless does provide a way to lower the RAM usage, but eventually crashes if I set it to less than 900MB. Also if a bot uses multiple CPUs it would be good to provide a parameter which limits the number of CPUs it uses.