Re: Lost /duplicated messages

[Stuart Booth <lists@xxxxxxxxxxxxxxxx>]

On Sun, 03 Jul 2005 01:02:52 -0000, "barrygordon"
<barry@xxxxxxx> wrote:

>I have an application where I need to  transfer large blocks of Data,
>lets say 2500-5000 bytes.  Knowing the UDP size limits I broke this
>down into multiple messages each message indicating its sequence number
>for reassembly at the other end so they are order independent.
>
>I see the messages going out (all of them) in the correct order (using
>a sniffer to monitor).  On the receiveing side i almost never get all
>the message blocks.  Most of the time I get n copies of the last block
>and none of the others.  Only once did I see al the blocks arrive.  I
>have tried delays between blocks on the transmit side, etc.  I am ready
>to pull  my hair (what little is left) out.  I have played with varying
>block sizes and varying delays between transmissions. The two PC's are
>2.4 GHZ machines and the network is a single subnet at 100 mbps.

Hi Barry,

I've just banged together a nobby pair of xAPplications using xFx that
send and receive a series of messages. They're a bit crude at the
moment but appear to work okay for me. I'm not seeing any message loss
on my network using this application, so perhaps I am misunderstanding
the nature of the problem here.

A couple of simple images (ie token documentation!) here:

<http://www.xapframework.net/modules.php?name=Content&pa=showpage&pid=17>

You'll find the download here:

xAP Message Loss Tester
<http://www.xapframework.net/modules.php?name=Downloads&d_op=viewdownload&cid=4>

There are two components to this package. The Tx application sends
however many messages you want with a interval up to one second
in-between.

The Rx application sits around until it detects a message in a
particular format coming in whereupon it starts counting until things
go quiet for a period of time.

The messages look like this:

xap-header
{
v=12
Hop=1
UID=FF109300
Class=MessageLoss.Tx
Source=KCSoft.MessageLossTx.anya
}
Tx
{
Item=1
Total=50
}

I can of course make them as complicated as required, but this
sufficies for now until I understand what exactly the problem is so
that I can  reproduce it better.

Item increments on each message and the messages are untargetted so
you can run multiple Rx components on different machines if you like.
I tested with 2 Rx components on different machines and a Tx part on
one of those 2 Rx machines. I have a number of other xAPps running at
the same time.

HTH,

S

PS - these both use a very development build of xFx and have had
barely any testing, so don't be surprised if they go Bang! somewhere.
--
Stuart Booth <stuart@xxxxxxx>
xAPFramework.NET - a xAP software development framework for .NET

http://www.xapautomation.org/ 
     http://www.xapframework.net/