[THIN] Re: 64 bit experience - repost

Alan - I think you would get a peformance increase on a citrix box with a
write cache on the controller. The write operations would be marked as
complete quicker as they'd be written to the cache rather than to disk.
 
Given a citrix box is probably going to be doing a decent amount of writing
(temp files, spool files, profile writes during logon, page file writes) its
likely there'd be an advantage in a system having one rather not - but how
significant that speed improvement would be in relation to the user
experience might be difficult to quantify. I'd have thought you'd only
notice the difference if, say they were all logging on at the same time, or
all performing write intensive operations, and then it may be some other
factor (network connection to the profile server, or database queries to the
sql box) that would cause a delay and your shiney write back cache in the
citrix server would be wasted. 
 
If you were looking at upgrading the controllers, maybe look at upgradeing
the file/exchange/sql servers with this sort of technology first if its not
already been done?
 

  _____  

From: thin-bounce@xxxxxxxxxxxxx [mailto:thin-bounce@xxxxxxxxxxxxx] On Behalf
Of Hutchinson, Alan
Sent: 09 June 2006 16:08
To: thin@xxxxxxxxxxxxx
Subject: [THIN] Re: 64 bit experience - repost


aaarh - what you say makes sense - my only defense, and it's not much of
one, is that it came out of a recommendation from M$ when we had some
performance issues some time ago - I really hadn't put my thinking head on
and questioned it. That said - forget the battery backed bit - don't you get
increased controller performance and if so is it significant ? 

  _____  

From: thin-bounce@xxxxxxxxxxxxx [mailto:thin-bounce@xxxxxxxxxxxxx] On Behalf
Of Andrew Wood
Sent: 09 June 2006 15:42
To: thin@xxxxxxxxxxxxx
Subject: [THIN] Re: 64 bit experience - repost


Would you need a battery backed write cache on a citrix server? Write back
cache is going to improve performance if you've a raid card as the write
operation is written quicker as it goes to the cache. Obviously the risk
there is that you write to the controller but not to the disk - so you use a
battery write cache to mitigate that. But on  a citrix server its unlikely
you've data that's going to need to be written to disk in that way - would
suggest its an unnecessary expense for most of the time. 
  _____  

From: thin-bounce@xxxxxxxxxxxxx [mailto:thin-bounce@xxxxxxxxxxxxx] On Behalf
Of Hutchinson, Alan
Sent: 09 June 2006 15:13
To: thin@xxxxxxxxxxxxx
Subject: [THIN] Re: 64 bit experience - repost


Yes, I agree - at first sight figures not only don't look good they look
seriously bad - then you get the 'reality check' as you put it with real
world applications. As an aside I've had someone working with me for the
past couple of months who's done some really good work on
benchmarking/profileing our existing setup. So good in fact that I'm trying
to scrounge one or two more servers to add so that we can measure it all
again. I hope to be able to apply most of this to any new setup and with the
above mentioned figures as a comparison get our own 'real world' check with
some sort of confidence.
 
As Benny says below (and I don't think that Tim was trying to put me off
either) I'll probably take the opportunity to get used to the technology -
cos if I don't do it now it'll be a long time before I get another chance
and PS7 will probably be out by then.
 
As an aside - I haven't seen anyone talk about battery backed write cache in
any of these presentations/slides etc. but I have seen mentions that it's a
must have (can't lay my hands on them when I need them). It seems that the
boxes we're currently purchasing this is still an optional extra. I'm
pleased I checked as I thought they were standard now.
 
Regards,
 
Alan.
 

  _____  

From: thin-bounce@xxxxxxxxxxxxx [mailto:thin-bounce@xxxxxxxxxxxxx] On Behalf
Of Andrew Wood
Sent: 09 June 2006 14:22
To: thin@xxxxxxxxxxxxx
Subject: [THIN] Re: 64 bit experience - repost


Just to follow this up I got hold of the slidedeck Benny did - my notes not
exactly the same as what Bnny had [damn it being *Pub*forum :( ]
 
Benny did some analysis testing with 64 bit comparing dual cores & 4GB ram ,
32 bit servers came out better (200 active session vs 159). With 4 cores you
got 319 sessions (win32) vs 171 for x64 - it was only when you added HT that
x64 got up to 322. So raw test analysis - not that impressive. 
 
However, (and er... its at this point I must have been writing down what was
said) in a 'reality check' with a more common application profile (office,
notes, couple of java apps) - x64 for a single dual core xeon gave @ +25%
more users. It was more for 2xDual cores.
 
He did stress that the migration is not easy  - incompatibilities will not
just be drives, but system tools, installation routines (some of which can
be 16bit) and internal scripts modifying the system files and registry) can
all cause problems.
 
Benny's suggestion was to try and get used to the technology, you'll need
some time to get comfortable with it. From his findings, its mine that its
not yet ready for production.
 
hope this helps.
 
  _____  

From: thin-bounce@xxxxxxxxxxxxx [mailto:thin-bounce@xxxxxxxxxxxxx] On Behalf
Of Andrew Wood
Sent: 09 June 2006 09:55
To: thin@xxxxxxxxxxxxx
Subject: [THIN] Re: 64 bit experience - repost


Alan, 
 
Look hard at the performance figures - there are some instances where there
are actually *lower* numbers when migrating to x64 - I'll see if I can get
my hands on a copy of the presentation :)

  _____  

From: thin-bounce@xxxxxxxxxxxxx [mailto:thin-bounce@xxxxxxxxxxxxx] On Behalf
Of Hutchinson, Alan
Sent: 08 June 2006 17:57
To: thin@xxxxxxxxxxxxx
Subject: [THIN] Re: 64 bit experience - repost


Thanks for that Andrew - one of my motives for looking at 64 bit (apart from
the technical challenge) is that once we get an environment up and running
smoothly here we tend not to change it for a couple of years or so (except
for the usual patches and supplier software upgrades). By that time I'll be
having problems with not having gone 64 bit and virtually no experience of
it. I am resigned to running mainly 32 bits apps at the moment and have read
of the performance hit of running wow64 so I certainly won't be selling it
as a way of reducing the overall estate. 
 
I've had a quick look at the pubforum web site and can only find "Citrix
Metaframe ala 64 bit - what does it give us" 
 
http://www.pubforum.net/vip/PubForum_x64_Citrix.ppt#259,1,64 bit
Presentation Server
 
by Simon Frost from Citrix. Like you said I'm not sure I believe the
scalability figures given here either.
 
At the moment I'm leaning heavily towards a simultaneous 32 and 64 bit build
and see what breaks first - as I said above I'd like to get my hands dirty
with this whilst I've got the opportunity.
 
Thanks for your input - really useful.
 
Regards,
 
Alan.
 


  _____  

From: thin-bounce@xxxxxxxxxxxxx [mailto:thin-bounce@xxxxxxxxxxxxx] On Behalf
Of Andrew Wood
Sent: 08 June 2006 15:09
To: thin@xxxxxxxxxxxxx
Subject: [THIN] Re: 64 bit experience - repost


Alan, 
 
Bernhard Tritsch did great presentation on 64 bit for TS at the last
pubforum. 
 
iirc the findings were essentially that the 64 bit environment didn't really
offer any additional benefit at present - in fact there could be more effort
involved in being an early adopter almost without gain. Issues identified
included getting device drivers for printers, and other hardware, anti-virus
support wasn't available from all vendors. He highlighted the fact that a
lot of existing apps are going to have to run in the windows on windows
emulation to allow the fact that they're 32 bit apps. You obviously can't
have anything older - 16bit apps won't run. This wow functionality for many
apps increased resource consumption. There were issues with the fact that
they've messed around with the system32/program files directories that can
lead to some applications not working correctly and being cumbersome to
install or not working at all.
 
More importantly, he load tested the same desktop app suite in a 32 and 64
bit environment. While the 64 bit environment could allow more sessions to
be created the apps in those (extra) sessions did not work well and were
very unreliable. Getting a user count that was reliable meant that you were
hitting about the same user count as with win32. He showed that the testing
M$ did to get the large amount of sessions working was performed over a
large amount of time - when you tried to get many users on in a short time
the environment did not hold up as well. 
 
I wish I had a copy of the powerpoint :(  it was a very compelling argument
to sitting tight until more apps were available natively on the x64
platform.
 
hth


  _____  

From: thin-bounce@xxxxxxxxxxxxx [mailto:thin-bounce@xxxxxxxxxxxxx] On Behalf
Of Michael Pardee
Sent: 08 June 2006 14:37
To: thin@xxxxxxxxxxxxx
Subject: [THIN] Re: 64 bit experience - repost


very close here.  As we build our new PS4 Farm I challenged the team to do
as much with the 64 bit version as possible.  I think we are just rolling.
I'll report back anything we find.


On 6/8/06, Hutchinson, Alan <Alan.Hutchinson@xxxxxxxxxxxxxxxxxx> wrote: 

No takers? I was hoping to provoke some discussion - either I'm way
behind the times and evrybody is using this or (and I can't believe
this) I'm slightly ahead of the game, or everybody has got one in their
labs and is keeping quiet .......... 

Regards,

Alan.


-----Original Message-----
From: thin-bounce@xxxxxxxxxxxxx [mailto:thin-bounce@xxxxxxxxxxxxx
<mailto:thin-bounce@xxxxxxxxxxxxx> ] On
Behalf Of Hutchinson, Alan
Sent: 07 June 2006 16:17
To: thin@xxxxxxxxxxxxx
Subject: [THIN] 64 bit experience

Well, as far as I can see this hasn't been aired for a couple of months 
so I'm wondering what the experience is out there. I have the
opportunity for a completely new build on a new infrastructure and am
toying with a simultaneous 32 and 64 PS server build to see how it goes.
I've seen the following : 

CTX105744 - but this is dated October last year and can't immediately
see any updates to this and the only thing that puts me off under
functionality not supported is 'Oracle' without any further explanation. 

KB282423 - again a few months old. The bits that concern me with this
one relate to MDAC (but on re-reading may not be an issue), and '64 bit
I.E. cannot load 32-bit ActiveX controls' - which may be the killer. 

I was encouraged by Brian Maddens article
http://www.brianmadden.com/content/content.asp?id=518 about 'dropping' a
64 bit PS server into an existing 32 farm. Although long term I don't 
particularly fancy running a mixed farm.

Thoughts, discussions, opinions, real experience please.

Regards,

Alan.
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-- 

Michael Pardee
www.blindsquirrel.org 

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