I did a study last year on the network latencies between our site in Philadelphia and 
various
points on the globe to define our SLA. Latencies between India and the US tended to be 
high - I
don't remember the exact numbers, but they were outside our specs - which was 10 
seconds, 95% of
the time, 5 seconds 99%. 3 seconds - I don't think so, unless you have a private pipe. 

There were times when latencies were low, but these tended to coincide with periods of 
low
internet activity in both the US and the target region. 

With this thought, I think that you will be spending more time waiting for the bits to 
get there,
than actually processing them.  Keeping round trips to a minimum should be your target.

Step one - however is to get an accurate measure of the latency between India and the 
US. Don't
just use a few samples. Take samples at regular intervals over a week or month - you 
may restrict
the hours to those that you expect to be doing business, but it is well considered to 
take into
account all (24 hour) the data so that you can plan for contingencies. All take into 
consideration
that there will be periods when the net is unusually active, as it might be if the US 
and Iraq mix
it up, or India has another incident with Pakistan.

Step two - write simple test cases using a simple web service, RMI, etc. and test them 
over the
WAN. Use a tool like sniff to get the number and timing of packets in the 
conversation. 
--- "U. Penski" <[EMAIL PROTECTED]> wrote:
> [jdjlist] Applet Questionthe below message apparently reached me directly instead of 
>the list -
> just forwarding it here
> 
> [EMAIL PROTECTED]
>   ----- Original Message ----- 
>   From: Yohannes, Yonas 
>   To: '[EMAIL PROTECTED]' 
>   Sent: Monday, November 11, 2002 10:00 PM
>   Subject: RMI over the Wan vs Soap (WebSErvices)
> 
> 
>   I am an architect building Call Center on WLS 5.1 (We are in processes of 
>migrating to WLS
> 6.1). Currently we are debating using RMI across the ocean (India to USA). We are 
>entertaining
> having a topology as follows web server (along with web container leveraging 
>STRUTS). So in
> essence calling the EJB across the ocean. There are two thought processes one to use 
>the RMI the
> other to make use of web services. The concern we have is that we are not convinced 
>that RMI
> would perform on a WAN setting though we know it does fine on LAN. Any thoughts? 
>Does anyone
> have experience with RMI over the WAN? Pros/Cons. We have a very aggressive 
>performance
> requirement of 3 sec over the ocean 
> 
> 
> 
> 
> 
> ____________________________________________________
> To change your JDJList options, please visit:
> http://www.sys-con.com/java/list.cfm
> 
> Be respectful! Clean up your posts before replying
> ____________________________________________________
> 


=====

Mark Zawadzki Performance Engineer/DBA/Programmer extraordinaire� [EMAIL PROTECTED] 
[EMAIL PROTECTED]

 "Democracies die behind closed doors," - Judge Damon Keith

 "The people of this country, not special interest big money, should be
the source of all political power. Government must remain the domain of
the general citizenry, not a narrow elite." - Sen. Paul Wellstone



__________________________________________________
Do you Yahoo!?
U2 on LAUNCH - Exclusive greatest hits videos
http://launch.yahoo.com/u2

____________________________________________________
To change your JDJList options, please visit:
http://www.sys-con.com/java/list.cfm

Be respectful! Clean up your posts before replying
____________________________________________________

Reply via email to