Does Bandwidth affect the performance of the Application While using LoadRunner?

[Placement]

I was running for different users in the LoadRunner.
But when i tried to run using different bandwidth's, i observed that
there was a huge difference in the responce time.
I can't understand why this has happened.
will the application's performance vary when the bandwidth changes?

[James Pulley]

Bandwidth will impact the performance of your application independent of test tool. Network is one of the four classical systems engineering restriction points, with CPU, memory and disk making up the other three.

If your app is network promiscuous and you restrict that resource either naturally or artificially then you are going to have an issue. On the other hand this gives you an opportunity to instruct your developers to build more wan friendly apps.

I recently ran up against a chatterbox myself and by making one change on the server (no source changes) response tim maximums dropped from two minutes to 20 seconds

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[Ruchi Dubey]

Sure the perforamnce will change....Bandwidth is basically the size of pipe i.e the amount of data that can be carried from one place to another in a given time period.

There are bsically two network factors which govern the performance i.e bandwidth and latency.

 

Latency is the delay introducted in the sytem due to physical distance.

[V.M.Guruprasath]

Bandwidth will affect Performance response time!

 

- V.M.Guruprasath

[André Luyer]

The latency or round trip time (RTT) will limit the maximum
throughput. The longer the distance the higher the latency (due to
processing in routers and the speed of light). A low bandwidth will
result in a high latency also, because of the slower serialisation of
the data packets.

Some protocols are more sensitive to latency than others. HTTP and FTP
are examples of protocols that not very sensitive. Windows network
share, the SMB protocol (version 1), is a classical example of a
protocol that will perform badly over a WAN (SMBv2 has been improved).
The most extreme example is the TFTP protocol. We call these protocols
'chatty'.

It is possible to calculate what the theoretical maximum throughput
will be using the bandwidth-delay product (BDP). See
http://en.wikipedia.org/wiki/TCP_tuning for TCP, but this also applies
to the buffer size of higher level protocols.

André

[kamal]

Ya guru i know that it will affect the performance response time. but could u be more specific(layman)

Since i am new to the performance testing concepts

Thanks and Regards

Kamal

[Barry Perez]

I'm afraid performance is not a subject for the "layman".

Why not run a few tests in order to understand for yourself what's
happening here?

Run some tests increasing the load.
Look at number of users, throughput, data transfer rates / other
metrics related to the network interface, page response times
Understand how they correlate - i.e. what is happening when response
times degrade?

On Apr 17, 11:05 pm, kamal <kamalbep...@gmail.com> wrote:
> Ya guru i know that it will affect the performance response time. but could
> u be more specific(layman)
> Since i am new to the performance testing concepts
>
> On Tue, Apr 17, 2012 at 12:57 AM, V.M.Guruprasath

> <vmgurupras...@gmail.com>wrote:

>
>
>
> > Bandwidth will affect Performance response time!
>
> > - V.M.Guruprasath
>
> >  On Mon, Apr 16, 2012 at 12:43 PM, Ruchi Dubey <ruc...@gmail.com> wrote:
>
> >> Sure the perforamnce will change....Bandwidth is basically the size of
> >> pipe i.e the amount of data that can be carried from one place to another
> >> in a given time period.
> >> There are bsically two network factors which govern the performance i.e
> >> bandwidth and latency.
>
> >> Latency is the delay introducted in the sytem due to physical distance.

> *Kamal*

[Bhushan Deodhar]

I think your question is already answered. However I am interested in knowing how can one adjust network bandwidth during the test? I am trying to test an application that uses smooth streaming concept and controlling network bandwidth availability during the test is crucial for it. Can this be done through Load runner or similar tools?

Thanks.
-Bhushan

[Gaurav Mishra]

there are many tools for network bandwidth simulation. but best of them is shunra, which is compatible with loadrunner. i don't know about others.

 

As it is just for knowledge you can start with some open source tool. Following link might help you.

 

http://www.myloadtest.com/free-wan-emulator/

[V.M.Guruprasath]

Try LoadRunner -> Run-time Settings->Network-> Speed Simulation

Regards,

V.M.Guruprasath

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