[THIN] Re: Citrix Farm performance over WAN
- From: "Andrew Wood" <andrew.wood@xxxxxxxxxxxxxxxx>
- To: <thin@xxxxxxxxxxxxx>
- Date: Mon, 11 Jul 2011 09:14:24 +0100
Ping tests should give an idea of latency - and stick in a traceroute to
count the number of hops. You could set ping tests from servers in site A to
the various file servers to get an idea of the latency.
However, you mention "Site A is running at around 75% utilisation according
to Citrix Load Evaluator" - with Site A being the only one utilised. Your
goal is to bring on-line site B to be live rather than have it as a backup
to "remove the SMB bottleneck". This could mean the majority of your
servers are hosted in/on site A: is that the case? In which case, a ping
test should show everything working just fine in terms of latency (although
you should always expect the unexpected).
The problem is that the SMB bottleneck is likely more between the Citrix
servers and the backend file stores. Splitting users between Citrix servers
on Site A & B isn't going to change the fact that (perhaps) the file servers
are struggling.
Citrix's Dan Allan did a nice piece on XenApp and File Server tuning
(http://bit.ly/ojqQ1r) - perhaps you've read that already? The important
fact to note is that the changes aren't XenApp server specific. Lanmanserver
changes need to be done on the file servers as well: this is of course on
the understanding that all your backend servers are plain old Windows 200x
boxes.
So - have you made those changes on any Windows 200x boxes you have? Also,
if you look at Dan's article there is mention of the a SMB client fix
(http://support.microsoft.com/kb/885189)
In addition to the above registry tuning, there was another SMB client fix
which reduces the SMB chatter and SMB commands that are opened from a client
to a file server. This registry setting is one that we recommend be
implemented on all XenApp Servers:
HKLM\SOFTWARE\Microsoft\Windows\CurrentVersion\Policies\Explorer
"NoRemoteRecursiveEvents"=dword:00000001
You can verify whether or not your system has excessive SMB commands being
queued by reviewing the following performance monitor counter on your XenApp
servers: Redirector/Current Commands. If this counter gets close to 50 (you
mention 170+) and you have not tuned your file servers, then you definitely
have a problem.
You seem to have a/some NetApp device(s). Is this the only filestore? If not
- don't forget lanmanserver changes on other boxes. Regardless, the above
reg entry might could well be useful.
Is Edgesight not in because you don't have the licenses, or just not got
round/got the resource to deploy it?
Hth
a.
From: thin-bounce@xxxxxxxxxxxxx [mailto:thin-bounce@xxxxxxxxxxxxx] On Behalf
Of Angela Smith
Sent: 09 July 2011 09:55
To: thin@xxxxxxxxxxxxx
Subject: [THIN] Re: Citrix Farm performance over WAN
Hi
Whats the best way to check min/max/avg latency?
No, unfortunately I dont have Edgesite
Thanks
Ang
_____
From: andrew.wood@xxxxxxxxxxxxxxxx
To: thin@xxxxxxxxxxxxx
Subject: [THIN] Re: Citrix Farm performance over WAN
Date: Thu, 7 Jul 2011 17:15:34 +0100
Yes, that's the thing I'd look at .
You've not got edgesight running have you angela?
From: thin-bounce@xxxxxxxxxxxxx [mailto:thin-bounce@xxxxxxxxxxxxx] On Behalf
Of Landin, Mark
Sent: 07 July 2011 15:00
To: thin@xxxxxxxxxxxxx
Subject: [THIN] Re: Citrix Farm performance over WAN
You are on a WAN. What's the min/max/avg latency between these sites at the
time that you experiencing these delays?
_____
From: thin-bounce@xxxxxxxxxxxxx [mailto:thin-bounce@xxxxxxxxxxxxx] On Behalf
Of Angela Smith
Sent: Thursday, July 07, 2011 5:05 AM
To: thin@xxxxxxxxxxxxx
Subject: [THIN] Re: Citrix Farm performance over WAN
Hi
Yes Servers are running Windows 2003R2 x86 with 10Gb RAM
_____
From: andrew.wood@xxxxxxxxxxxxxxxx
To: thin@xxxxxxxxxxxxx
Subject: [THIN] Re: Citrix Farm performance over WAN
Date: Thu, 7 Jul 2011 10:50:46 +0100
Whats on the xenapp servers - 2003?
From: thin-bounce@xxxxxxxxxxxxx [mailto:thin-bounce@xxxxxxxxxxxxx] On Behalf
Of Angela Smith
Sent: 07 July 2011 10:20
To: thin@xxxxxxxxxxxxx
Subject: [THIN] Re: Citrix Farm performance over WAN
Great question. Wish I knew how to troubleshoot it. Our storage guy says
there are no issues on the NetApp NAS (Unix based I think) so I have to
believe him. Ive run some perfmon stats on my citrix server and have high
readings for Redirector\Current Commands
Citrix Server
MaxMpxCt is set to 1024
MaxWork Items is set to 4096
NAS
CIFS MPX is set to 1124
Perfmon results
Redirector\Current Commands: Min 155, Max 246. Average 170
Server\Work Item Shortages: 0
Server Work Queues\Available Work Items: Min 30, Max 30, Average 30
Any suggestions on how to tweak server would be muchly appreciated
Regards
Angela
_____
From: andrew.wood@xxxxxxxxxxxxxxxx
To: thin@xxxxxxxxxxxxx
Subject: [THIN] Re: Citrix Farm performance over WAN
Date: Tue, 5 Jul 2011 17:27:16 +0100
Depends what your root cause of "SMB bottleneck" if its "back end file
server" its unlikely this configuration is going to help.
From: thin-bounce@xxxxxxxxxxxxx [mailto:thin-bounce@xxxxxxxxxxxxx] On Behalf
Of Angela Smith
Sent: 03 July 2011 07:17
To: thin@xxxxxxxxxxxxx
Subject: [THIN] Citrix Farm performance over WAN
Hi
We currently have 30 XenApp 5 Servers split between 2 Sites. Sites are
connected by Gig Links. At present we use Zone Preference and Failover and
Site A is Active only. Site B is for Disaster Recovery only. Site A is
running at around 75% utilisation according to Citrix Load Evaluator. As
per my previous emails we are having issues with SMB bottleneck. I am
considering removing Zone Pref and Failover and making Site B active also.
Therefore all XenApp servers get utilised which will half the resource
requirements on my servers and hopefully remove any bottlenecks.
Can anyone see an issue with running with such a config. XenApp Servers in
site B will need to cross the Gig link to connect to File Server/Web
interface but on a gig link I think should be OK. Any pro's/con's with this
approach?
Thanks
Ang
_____
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