ThroughPut : Small vs Large Messages

[Charles Anthony <ch...@hpdsoftware.com>]

Hi,

We use AMQ (4) as the client/server transport in our system. For some of our
clients, we host the application at our site, and though connect remotely
via VPN. Sometimes, we (well, usually they) have trouble setting up the VPN
and setting firewall configs etc - so I am just knocking together a little
noddy diagnostics program - i.e. connect to the AMQ server, create a temp
queue, create a producer, create a consumer, send and receive a load of
messages.

All well and good.

I thought I'd go a bit crazy, then, and try and work out message throughput
based on message size (i.e. send & reveive A x byte[B] => bytes sent = A*B,
bytes-per-second= A*B/num-secs) - not as a real measurement, but more as
wavy-hand type uide. 
I've turned async send off for this diagnostic thingy, and messages are sent
NON_PERSISTENT.

Here's the weird thing.

If send small messages ( < 1300 ish bytes), I am getting roundtrip of approx
200 ms
If send larger messages ( > 1300 ish bytes - say 2048), I am getting
roundtip of < 15 ms


Is there a reasonable explanation for this ? Maybe compression kicking in ?
I'm just a bit befuddled.

Cheers,

Charles.


___________________________________________________________
HPD Software Ltd. - Helping Business Finance Business
Email terms and conditions: www.hpdsoftware.com/disclaimer 

Re: ThroughPut : Small vs Large Messages

[James Strachan <ja...@gmail.com>]

It could be the Nagler kicking in - i.e. it might take a little while
for the TCP buffers to be flushed to the network for smaller messages.
You can tune TCP to enable/disable waiting for complete tcp buffers
before actually sending it to the network - its a throughput v latency
tradeoff setting.

On 6/22/06, Charles Anthony <ch...@hpdsoftware.com> wrote:
> Hi,
>
> We use AMQ (4) as the client/server transport in our system. For some of our
> clients, we host the application at our site, and though connect remotely
> via VPN. Sometimes, we (well, usually they) have trouble setting up the VPN
> and setting firewall configs etc - so I am just knocking together a little
> noddy diagnostics program - i.e. connect to the AMQ server, create a temp
> queue, create a producer, create a consumer, send and receive a load of
> messages.
>
> All well and good.
>
> I thought I'd go a bit crazy, then, and try and work out message throughput
> based on message size (i.e. send & reveive A x byte[B] => bytes sent = A*B,
> bytes-per-second= A*B/num-secs) - not as a real measurement, but more as
> wavy-hand type uide.
> I've turned async send off for this diagnostic thingy, and messages are sent
> NON_PERSISTENT.
>
> Here's the weird thing.
>
> If send small messages ( < 1300 ish bytes), I am getting roundtrip of approx
> 200 ms
> If send larger messages ( > 1300 ish bytes - say 2048), I am getting
> roundtip of < 15 ms
>
>
> Is there a reasonable explanation for this ? Maybe compression kicking in ?
> I'm just a bit befuddled.
>
> Cheers,
>
> Charles.
>
>
> ___________________________________________________________
> HPD Software Ltd. - Helping Business Finance Business
> Email terms and conditions: www.hpdsoftware.com/disclaimer
>
>
>


-- 

James
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