[erlang-questions] Re: 20k messages in 4s but want to go faster!

Joel Reymont <>
Fri Jul 10 22:17:12 CEST 2009


On Jul 10, 2009, at 9:07 PM, Jim Morris wrote:

> I am wondering if you are not including in
> your timing the process death and processing of the DOWN message as
> well, which could be a lot longer than sending/receiving the message.

I _am_ including all that in the timing, which probably skews my stats.
That overhead would not be present when sending to a browser-based  
client.

> I suspect you are only interested in the latency between the bot
> sending the message and the 20k clients getting that message, not
> process exit time and associated garbage cleanup etc.

Absolutely right.

> In your case if the bots can communicate with the bot manager and all
> are running on the same node,

Bots are running on different servers to spread the load.

> maybe you could send the timestamp of
> when each bot gets the message to the bot manager, and the timestamp
> when the message was sent,

I like the idea and I thought about it. I'm not sure if the EC2  
instances are time-synced, though.

There's the same monitoring and DOWN message overhead involved in  
firing the timer in the bots since I need to broadcast when all bots  
are ready and that's when bots tart their timers.

A process exits when 'bumped' by the required number of bots. Both the  
broadcasting bot and the  client bots listen for DOWN from this single  
process to publish and start timing.

	Thanks, Joel

---
Mac hacker with a performance bent
http://www.linkedin.com/in/joelreymont



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