Re: Schedulers

[Guillermo Rodriguez Garcia <guille@iies.es>]

John,

Thanks for your reply. I thought that List was the default
scheduler (I read this in the ns Docs and didn't look at
the code in ns-lib.tcl - my fault). Is there any advantage
in Heap over Calendar?

Yes, my requests and responses are going through Tcl, but
I cannot avoid this, because at each node, each packet is
processed by running a user-supplied Tcl procedure (this
is a design requirement). I'm not using TCP; my protocol
runs over IP.

Any other ideas?

Thanks again,
G.

John Heidemann wrote:
> 
> On Fri, 26 Nov 1999 19:09:37 +0100, Guillermo Rodriguez Garcia wrote:
> >Hi all,
> >
> >I am doing several simulations for moderately large
> >topologies (about 1000 nodes). Each of these nodes
> >holds a client which produces about 10 requests per
> >second. These requests travel to the server where
> >they are serviced, and a 'response' packet is
> >sent back for each request. The simulation runs
> >for about one minute (simulation time). This means
> >that a lot of packets are generated. Currently,
> >each simulation lasts for about 6-7 hours (real
> >time). I would like to reduce this time.
> >
> >I am using hierarchical routing but I cannot use
> >SessionSim due to subtle details.
> >
> >Should I use a scheduler different than the
> >'standard' one? Which are the differences between
> >the list, heap and calendar schedulers?
> 
> The default scheduler (calendar) is quite fast.
> (List is quite slow.)
> 
> Are your requests and responses going through Tcl?  You don't give
> many details, but if each req/resp is just a couple of packets over
> TCP, all driven from Tcl, that's a lot of language switching overhead.
> 
>    -John Heidemann

-- 
Guillermo Rodriguez Garcia
<guille@iies.es>