[ic] StartServers and RAM

[Jon Jensen]

On Fri, 14 Jun 2013, Grant wrote:

> I'm experimenting with different values for StartServers and I've 
> discovered that most of the resident memory associated with IC processes 
> seems to be shared.  'top' shows each of my processes have over 100M 
> resident memory and yet doubling or tripling the StartServers value 
> barely changes the -/+ buffers/cache values in 'free'.  I'm also using 
> MaxRequestsPerChild 100 and ChildLife 3600.
>
> Has anyone found a good method/formula for maximizing StartServers and 
> preventing OOM?  How much RAM should you have for StartServers 150 for 
> example?
>
> Is RAM the only consideration when tuning StartServers?

RAM and CPU and workload (I/O or CPU bound?).

A good rule of thumb would be to have maybe 2-5 Interchange child 
processes per CPU core. It's hard to see the use of more than that unless 
you have a heavily database-bound setup where many IC children need to be 
serving a request but wait around a lot not burning CPU. But if you're 
CPU-bound in Interchange and things get busy, they'll just be fighting 
against each other if you get too many at the same time.

Jon

-- 
Jon Jensen
End Point Corporation
http://www.endpoint.com/