[PLUG] LAN broadcast?

[Wayne E. Van Loon Sr.]

Daniel Herrington wrote:
> Tim wrote, On 06/01/2011 08:31 PM:
>   
>> Hi Wayne,
>>
>>     
>>> I have a question about user applications using broadcast on a LAN.
>>>
>>> I usually have several processes that connect via TCP/IP to a central
>>> server that solves some optimization problems. In more demanding project
>>> that I am working on now, I hope to distribute the optimization problem
>>> between 24 to 36 helper processes.
>>>
>>> At the start of each optimization job, I will have a few data files that
>>> need to be distributed to each of the helper optimization processes.
>>> Rather than have the central optimizer / server send these files 24
>>> times, some way to broadcast these files to all machines / processes at
>>> the same time might be nice.
>>>
>>> Is that the kind of thing that broadcasting could accomplish?
>>>
>>> And if so, and in a big picture way, how would one do it?
>>>       
>> You could use broadcast, yes.  Most likely you would want to use UDP
>> for this, since TCP handshakes and broadcast doesn't really mix.  To
>> accomplish this, you would simply have each helper process listen for
>> the broadcast messages and then send results back to the central
>> server at the server's unicast address.
>>
>> However, a "sexier" way of accomplishing the same thing would be to
>> use multicast.  This would allow you to distribute the broadcast
>> messages scalably across router boundaries.  Multicast is really
>> powerful for specific applications like this and I hope it catches on
>> some day, since it can completely replace distribution models like
>> bittorrent.
>>     
> I have found that in most enterprise environments, network admins have 
> shutdown multicast at the routers. One of the applications we work with 
> uses multicast for data sync, and invariably we need the network guys to 
> open up multicasting across subnets.
>
> Not sure if it's a concern for the project you're working on, but if you 
> go that route I would check with the network guys.
>   
No network admins here. Simple little LAN in an industrial environment, 
half a dozen hex-core Linux boxes, a couple of 3D imagers and some 
ethernet I/O.

Thanks for your response
Wayne