[THIN] Re: Video Performance
- From: "Steve Greenberg" <steveg@xxxxxxxxxxxxxx>
- To: <thin@xxxxxxxxxxxxx>
- Date: Tue, 22 Jul 2008 10:12:26 -0700
Wow..worse than I expected!
Steve Greenberg
Thin Client Computing
34522 N. Scottsdale Rd D8453
Scottsdale, AZ 85266
(602) 432-8649
www.thinclient.net
steveg@xxxxxxxxxxxxxx
_____
From: thin-bounce@xxxxxxxxxxxxx [mailto:thin-bounce@xxxxxxxxxxxxx] On Behalf
Of Chris Grecsek
Sent: Tuesday, July 22, 2008 8:54 AM
To: 'thin@xxxxxxxxxxxxx'
Subject: [THIN] Re: Video Performance
Our first "test" was the subjective multi-media experience test and we were
surprised to see that the multi-media experience was "the same" on the VM
CSG and on the physical CSG box. At that point we decided to get a bit more
scientific/gather concrete evidence to confirm that result via the
performance counters.
The test was late in the day so there were maybe 70 users on the VM CSG and
yes, we only had the single user on the physical CSG. They physical CSG was
a modern dual proc, dual core box w/4gig or ram so it wasn't a gimped box in
any way. Actually we used the most powerful spare box we could find just to
try to make the physical test box look as good as it could.
-----------------------------
chris grecsek | centered networks | t:415-294-7776 | f:415-294-7772 |
<mailto:chris@xxxxxxxxxxxxxxxxxxxx> chris@xxxxxxxxxxxxxxxxxxxx
_____
From: thin-bounce@xxxxxxxxxxxxx [mailto:thin-bounce@xxxxxxxxxxxxx] On Behalf
Of Steve Greenberg
Sent: Monday, July 21, 2008 11:35 PM
To: thin@xxxxxxxxxxxxx
Subject: [THIN] Re: Video Performance
That is good feedback, thanks for coming back and sharing the results. I
wonder, on the physical box, aside from counters, did you subjectively
experience better multi-media performance? You said that the test box only
had one session on it, I have to think it performed better than the VM with
400 users?!?
Steve Greenberg
Thin Client Computing
34522 N. Scottsdale Rd D8453
Scottsdale, AZ 85266
(602) 432-8649
www.thinclient.net
steveg@xxxxxxxxxxxxxx
_____
From: thin-bounce@xxxxxxxxxxxxx [mailto:thin-bounce@xxxxxxxxxxxxx] On Behalf
Of Chris Grecsek
Sent: Monday, July 21, 2008 10:38 PM
To: 'thin@xxxxxxxxxxxxx'
Subject: [THIN] Re: Video Performance
I thought I'd share the results of our testing in comparing video
performance between a VM WI/CSG and a physical WI/CSG. We measured a number
of counters with respect to session latency, bandwidth usage, etc. and it
turns out that our performance/metrics was just about identical on the VM as
on the physical machine. The VM CSG still had a number of active sessions
and the physical only had a single, test session running on it.
We were able to isolate the performance issue to the CSG - we confirmed that
the WI is not part of the degradation.
So, while this was good in that we now have a definitive answer in that no
matter how much available bandwidth we have to help improve video quality,
it won't get any better as long as we're connecting through a CSG. I guess
it's time to get an eval of the Netscaler products.
Thanks!
Chris
-----------------------------
chris grecsek | centered networks | t:415-294-7776 | f:415-294-7772 |
<mailto:chris@xxxxxxxxxxxxxxxxxxxx> chris@xxxxxxxxxxxxxxxxxxxx
_____
From: thin-bounce@xxxxxxxxxxxxx [mailto:thin-bounce@xxxxxxxxxxxxx] On Behalf
Of Steve Greenberg
Sent: Friday, July 18, 2008 4:26 PM
To: thin@xxxxxxxxxxxxx
Subject: [THIN] Re: Video Performance
NIC is I/O and in a virtualized environment it has significant overhead in
that a software layer is added to virtualize the NIC in a way that slows it
down quite a bit. I would suggest, in general, that with 400 concurrent
connections you have exceed what a VMWare based CSG can effectively handle,
probably by quite a bit actually. The quick and easy proof is to spin up a
CSG on a raw box and check the different in response times. The overhead in
this case is not going to show in monitored utilization but more in the user
experience of latency on the rich media stuff you are referring to. It is
not a matter of utilization of VMWare resources as much as the fact that the
virtualization I/O translation layer is simply too inefficient. Stay tuned-
later this year Intel promises to have hardware NICS that are virtual
machine aware.
The Netscaler is the product I am referring to. If you buy Netscaler
Enterprise it includes a feature called Access Gateway. However, you can
also buy the same product with only the gateway feature and it is called
Access Gateway Enteprise Edition. It is very confusing, but in the end they
are the same box with different software licenses loaded!!
Steve Greenberg
Thin Client Computing
34522 N. Scottsdale Rd D8453
Scottsdale, AZ 85266
(602) 432-8649
www.thinclient.net
steveg@xxxxxxxxxxxxxx
_____
From: thin-bounce@xxxxxxxxxxxxx [mailto:thin-bounce@xxxxxxxxxxxxx] On Behalf
Of Chris Grecsek
Sent: Friday, July 18, 2008 1:50 PM
To: 'thin@xxxxxxxxxxxxx'
Subject: [THIN] Re: Video Performance
Excellent feedback - thanks Steve! When you say VMware is bad with I/O do
you mean disk or NIC or both? The perfmon counters we're running on the VMs
show very little utilization of disk or NIC so I guess we'll just see how it
goes.
We do have the WI and CSG on two separate VMs. We have about 400 concurrent
connections on this WI/CSG set.
You also mentioned the Netscaler Access Gateway as a possible upgrade path
from the WI/CSG. I'm doing some research but I must say, Citrix's product
naming bonanza makes me not 100% sure I'm looking at the correct product. I
found information on the Access Gateway Enterprise Edition (AGEE) but is
that a different product than the Netscaler Access Gateway? Was there a
specific feature of the product that you think would be making the
difference or is it just the fact that the device is designed to
handle/manage that specific type of traffic/load?
-----------------------------
chris grecsek | centered networks | t:415-294-7776 | f:415-294-7772 |
<mailto:chris@xxxxxxxxxxxxxxxxxxxx> chris@xxxxxxxxxxxxxxxxxxxx
_____
From: thin-bounce@xxxxxxxxxxxxx [mailto:thin-bounce@xxxxxxxxxxxxx] On Behalf
Of Steve Greenberg
Sent: Friday, July 18, 2008 1:07 PM
To: thin@xxxxxxxxxxxxx
Subject: [THIN] Re: Video Performance
Now that we know it is running on VMWare that could be the bottleneck right
there- CSG is I/O intensive because of the nature of what it is doing as a
proxy, this is the one area that hypervisor virtualization is still very
weak at..
Steve Greenberg
Thin Client Computing
34522 N. Scottsdale Rd D8453
Scottsdale, AZ 85266
(602) 432-8649
www.thinclient.net
steveg@xxxxxxxxxxxxxx
_____
From: thin-bounce@xxxxxxxxxxxxx [mailto:thin-bounce@xxxxxxxxxxxxx] On Behalf
Of Chris Grecsek
Sent: Friday, July 18, 2008 11:21 AM
To: 'thin@xxxxxxxxxxxxx'
Subject: [THIN] Re: Video Performance
Hi Joe,
Thanks for the speedy response!
We're not using any LBs - there are no network devices other than a standard
PIX.
The WI and CSGs are both VMs on ESX 3.5. Based on your question I think
we'll setup a WI/CSG on a standalone server "just to see" even though we're
not seeing high utilization.
At this point we have not isolated the WI or CSG. We're going to setup an
additional site on the WI that will not use the CSG so that should achieve
the isolation.
We've done quite a bit of testing with the speedscreen/multimedia stuff - I
think we've tried every conceivable combination in the policies and farm
settings . I believe the policies should apply the same whether we come in
via the CSG/WI or the PN.
Image acceleration using lossy compression: enabled; compression
level: do not use lossy compression; speedscreen progressive
display:disabled
Speedscreen browser acceleration: off; speedscreen flash:
enabled - all connections; speedscreen multimedia: enabled - buffer = 10.
Thanks again,
Chris
-----------------------------
chris grecsek | centered networks | t:415-294-7776 | f:415-294-7772 |
<mailto:chris@xxxxxxxxxxxxxxxxxxxx> chris@xxxxxxxxxxxxxxxxxxxx
_____
From: thin-bounce@xxxxxxxxxxxxx [mailto:thin-bounce@xxxxxxxxxxxxx] On Behalf
Of Joe Shonk
Sent: Friday, July 18, 2008 10:35 AM
To: thin@xxxxxxxxxxxxx
Subject: [THIN] Re: Video Performance
It could be a couple of things.. Have you tried removing CSG from the
equation and isolate if its WI or CSG? Is your CSG box running in a Virtual
Machine? Do you have a LB in front of your WI and/or CSG box? How are you
Applying the Ctx Policies for the SpeedScreen/multimedia.
Joe
From: thin-bounce@xxxxxxxxxxxxx [mailto:thin-bounce@xxxxxxxxxxxxx] On Behalf
Of Chris Grecsek
Sent: Friday, July 18, 2008 10:24 AM
To: 'thin@xxxxxxxxxxxxx'
Subject: [THIN] Video Performance
We provide published desktops via Citrix/terminal services delivered via the
internet. All users come in through the web interface/CSG via high speed,
burstable (up to 100mb) connections. Most of the branch offices are <50
users so connectivity/maxxing out the pipe is not an issue. We don't use any
bandwidth restriction policies - users can use as much bandwidth as they'd
like. We have bandwidth monitoring to look at all traffic and have our
firewalls setup so that only Citrix traffic is using the burstable
connection. Latency is sub 20ms and we have no packet loss.
Like everyone else using Citrix we've had challenges with video performance
on the published desktop (Windows media player works great - Flash/other
codecs, not so much). We had an interesting discovery today and I was
curious if anyone could answer why/how this happens.when we connect to a
published desktop via the WI/CSG (from one of our branch offices) video
performance is bad. We ran a test today from within the datacenter where we
connected to a published desktop, locally (from a laptop at the DC), using
the Program Neighborhood as opposed to coming in over the WI/CSG and low and
behold, video performance was excellent.
When we look at the amount of session bandwidth being used it's nearly the
same when coming in via the WI/CSG as it is when testing at the datacenter.
So I guess the question is, is there something with the way the WI/CSG works
that would be restricting/degrading the video performance (we ran
performance counters on the WI/CSG and it doesn't seem to be working very
hard), is there a difference between using the Program Neighborhood verses
the web client, etc.?
We're on Citrix 4.5, latest rollups, latest version of the client, etc.
If anyone has any ideas, it would be much appreciated.
Thank you!
Chris
-----------------------------
chris grecsek | centered networks | t:415-294-7776 | f:415-294-7772 |
<mailto:chris@xxxxxxxxxxxxxxxxxxxx> chris@xxxxxxxxxxxxxxxxxxxx
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