[Spread-users] Spread bandwidth throttling

Sonam Chauhan sonam.chauhan at ce.com.au
Wed Nov 14 01:19:17 EST 2007


Thanks a lot Jonathan. 

The application does not lend itself to simple bandwidth limiting - so I
was hoping to limit bandwidth either in Spread or the network interface.


> 'fixed' bandwidth limit could have the problem that the clients
actually 
> send faster then that and so more and more messages have to be
buffered up 
> in the daemons -- eventually causing very high latency for message 
> delivery and possible blocking of the sending clients (because the
daemon 
> won't buffer more messages for them)

Latency is no problem, but eventually blocking would be. Can message
buffer limits be set in the daemons? Can they daemons be set to buffer
messages, say, on disk, instead of in-memory? 

Kind regards,
Sonam Chauhan
-- 
Corporate Express Australia Ltd. 
Phone: +61-2-93350725, Email: sonam.chauhan at ce.com.au

-----Original Message-----
From: Jonathan Stanton [mailto:jonathan at cnds.jhu.edu] 
Sent: Wednesday, 14 November 2007 1:58 PM
To: Sonam Chauhan
Cc: Spread Users
Subject: Re: [Spread-users] Spread bandwidth throttling

Spread doesn't have any bandwidth limiting built in, however the load it
puts on the 
network "in addition to the application messages your clients send" is
quite small and 
mainly involves a small token packet making rounds of all of the daemons
(if idle it only 
circles every second or so, if nodes are sending it circles more often)

So if you do bandwidth limiting at the application client level by
limiting how many 
messages you send, the actual network load should be close to what you
send through the 
clients.

Since Spread just disseminates the messages your applications generate,
any 'fixed' 
bandwidth limit could have the problem that the clients actually send
faster then that and 
so more and more messages have to be buffered up in the daemons --
eventually causing 
very high latency for message delivery and possible blocking of the
sending clients 
(because the daemon won't buffer more messages for them)

Your solution using virtual network interfaces which are bandwidth
limited should work
fine (noting, however, the observations in the previous paragraph).
Spread can be
configured to bind to specific interfaces for daemon-daemon traffic and
client-daemon
traffic. Check out the sample configs in sample.spread.conf in the
source distribution. 

Cheers,

Jonathan

On Mon, Nov 12, 2007 at 10:42:54AM +1100, Sonam Chauhan wrote:
> Hello! 
> 
>  
> 
> I am new to Spread. I am interested in using it to stream results in a
> distributed load testing application where messages flow from the
> testing nodes to a central log server. 
> 
>  
> 
> The issue is that the load testing itself consumes a lot of network
> bandwidth. Does Spread or the Spread client have any bandwidth
> throttling/ bandwidth-limiting features that can limit it's network
> utilization? For instance, can I specify that Spread messages
throughput
> from a client not exceed 10 Mbps? 
> 
>  
> 
> If not, what would be the best way to achieve what I have in mind?
Would
> it be to setup virtual network interfaces limited to 10 Mbps and have
> the Spread components bind to those interfaces? 
> 
>  
> 
> Kind regards,
> 
> Sonam Chauhan
> 
> -- 
> 
> Corporate Express Australia Ltd. 
> 
> Phone: +61-2-93350725, Email: sonam.chauhan at ce.com.au
> 
>  
> 

> _______________________________________________
> Spread-users mailing list
> Spread-users at lists.spread.org
> http://lists.spread.org/mailman/listinfo/spread-users


-- 
-------------------------------------------------------
Jonathan R. Stanton         jonathan at cs.jhu.edu
Dept. of Computer Science   
Johns Hopkins University    
-------------------------------------------------------




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