Performance
Tuning your .NET Applications
Host: Ajay Solanki – Consultant, Microsoft Consultancy Services,
India
June
27, 2002
KunalS_MS: Good afternoon to all present
KunalS_MS: Welcome and thanks for joining to the MSDN India Expert
Chat Session
KunalS_MS: Todays topic of expert chat is - Performance Tuning your
.NET Applications
KunalS_MS: and our expert host is Ajay Solanki
KunalS_MS: Ajay is a Consultant with Microsoft Consultancy Services,
India
KunalS_MS: and one of our key experts on .NET implementation
AjayS_MS: Hi once again
Moderator: (Viral) What is the performance overhead for .NET component
hosted in COM+?
AjayS_MS: There is no perfomance overhead, the performance
penalty is more apparent in COM/ Interop
Moderator: (Viral) In DNA we have 3 tier model with Dll hosted in
MTS / COM+. What should be .Net deployment for max performance benefit?
AjayS_MS: To gain max performance the basic 3-Tier principle
i.e COM+ hosting biz logic and a light UI yet holds true.
AjayS_MS: deployment strategy yet remains the same.
Moderator: (Saurabh) We have read a lot about performance tuning for
ASP.NET applications, but not much for Win Forms applications. I understand
the enviornment is different, still what are the key areas to look
out in Win Forms apps?
AjayS_MS: Winforms have been an area to watch out for,
its not just Winforms alone but assemblies in general.
AjayS_MS: You need to watch out for the working set for
Winforms, there will be tools out soon for the same
Moderator: (Viral) Can I have a VC 6 .exe and .Net Dll? Will this
function without any penalty? Moreover will a simple re compilation
of vc6 code to vc7 improve the performance or not?
AjayS_MS: A VC6 to .NET call is expensive / or any boundary
crossing increases with the overhead of marshalling.
AjayS_MS: Moreover a direct compilation from VC6 to VC7
managed will not achieve an 100% straight migration, you will need
to go back the migrated code and make changes.
Moderator: (Saurabh) Can you please elaborate on the tools for Winforms?
And what are the things we need to watch out for?
AjayS_MS: vadump.exe / I am not sure if its out but do
check/ Ideally look out for working set, cold startup time/ warm startup
time etc
Moderator: (Viral) Are MSMQ triggers a good option to invoke components
in .Net do they have any performance penalties? Are they available
for MSMQ 2.0?
AjayS_MS: MSMQ triggers don’t have a penalty as such,
and yes they are available in MSMQ 3.0 also.
Moderator: (ronaldo) In web applications for any kind of form data
vaidation should we use the .net controls or ususal client side javascript
validation? if we go for .net controls what will be the advantage?
AjayS_MS: .net controls definitely do give an programmin
model adv. / however not much diff in performance
Moderator: (Manish_MVP) If .NET to COM marshalling is an issue, a
COM library is binary. Will this have an impact? These issues has
not been answered properly anywhere.
AjayS_MS: Marshalling is always been an area of concern
AjayS_MS: If you are looking basic COM/Interop it has
an overhead 31 instruction minimum and rest varies on the data been
marshalled.
Moderator: (madhu) What is the optimized way of loading the Assembly?
AjayS_MS: Let say if you loading an assembly for a single
method, you are a paying a tremendous penalty here, see if you can
duplicate.
AjayS_MS: the method's functionality using the code already
loaded.
AjayS_MS: And also there is a working set associated
with each assembly loaded.
Moderator: (Viral) If we want to migrate VC6 to VC7 unmanaged code,
will this give the necessary performance numbers say a 30% improvement?
AjayS_MS: One more thing any method body beyond 64 local
variables and 3000 lines code is very heavy on the JIT compilation
process
AjayS_MS: migrating from VC6 to VC7 will give a definite
performance boost and also depends on the code quality
Moderator: (Viral) We have an application where in we are planning
a phased migration to .net , just needed to know whether ADO and ADO.net
will co exist on the same server and does this have any performance
implications?
AjayS_MS: in .net its on ADO.NET / as you see there is
a striking difference b/w ADO and ADO.NET.
AjayS_MS: I think you should be considering moving completely
to ADO.NET one short.
Moderator: (ronaldo) What is the performance overhead if I host .NET
assemblies in COM+ environment?
AjayS_MS: Performance overhead if its is end 2 end .NET
/ COM+ none, If COM/Interop a basic penalty of 31 instruction varying
depending on marshalling requirement
Moderator: (Viral) Will Windows API call also be considered as marshalling
out of .NET Framework?
AjayS_MS: Windows API / the whole set is available in
.NET/ If you are exclusively calling an Win 32 API from the .NET frame
yes there will be marshalling come into play
Moderator: (madhu) But, there are different methods to load the assembly.
Is there any method which will give me good performance?
AjayS_MS: Actually Assembly loading there are 2 concern
areas the load time and the working set. You need to put all the relevant
method in the same assembly .
AjayS_MS: Yes if it is just a single method you dont
have an option you pay the penalty
Moderator: (Bharat) Is performance increased by deploying .NET components
in COM+?
AjayS_MS: there are no stats available on this so far,
But I believe no performance difference, probably very minimal in
terms of object cycle.
Moderator: (Bharat) Can you tell me the criterias for using COM+ with
.NET?
AjayS_MS: COM+ in .NET is a continued trend as what you
did in DNA/ COM+ , The criteria to use is the same as 3 Tier architecture
Moderator: (Saurabh) Ajay you just said - "Windows API / the whole
set is available in .NET". But I find that the .NET framework is only
a very small subset of Win32 API; is there a new version coming up?
AjayS_MS: Saurabh ideally what Win 32 API in .NET are
u lookin at
Moderator: (Saurabh) Multimedia, Hardware Access (COM/USB) etc.
AjayS_MS: Hardware access you have the entire Management
namespace/Multimedia I have to check on
Moderator: (madhu) What will happen if memory is allocated by an unmanaged
code, and this code is called from .NET. When will the memory allocated
by the unmanaged code be released?
AjayS_MS: unmanaged code memory allocation is an overhead,
memory allocation is on execution but the memory releasing is a question
as there is a seperate entity/thread which keeps track of this.
Moderator: (madhu) Also what is the performance hit between calling
a windows dll and com dll?
AjayS_MS: If unmanaged, yes!
Moderator: (Bharat) The RCW is an intermediate layer through which
you have go to access COM+. Is there no overhead in invoking COM+
components from .NET?
AjayS_MS: , the standard RCW or CCW that is generated
by the runtime provides adequate marshaling for calls that cross the
boundary between COM and the .NET Framework. Using custom attributes,
you can optionally adjust the way the runtime represents managed and
unm
Moderator: (ronaldo) Do you have any statistics regarding performance
improvement between COM/ADO environment and .NET/ADO.NET? This is
very important before deciding to change any application.
AjayS_MS: COM/ADO vs .NET/ADO.NET is an indirect way
to look at performance the basic is moving an VB6 app to VB.NET does
give you around 25% performance improvement and these statistics are
based on MS Nile application test -
http://www.gotdotnet.com/team/compare/nileperf.aspx
Moderator: (Saurabh) Ajay, I thought the Management namespace is used
to access WMI. I don't see any classes there that help me *program*
against raw hardware devices?
AjayS_MS: WMI would give you APIs to monitor any kind
of devices (raw also)/ RAW Device API I have check on this
Moderator: (madhu) Can you give me some stats between the two, i.e.,
callling a windows dll and calling a com dll?
AjayS_MS: Platform invoke allows managed code to call
unmanaged functions that are implemented in a DLL. Platform invoke
provides the mechanism for finding and invoking unmanaged functions,
as well as marshaling managed arguments to and from unmanaged code.
When ma
AjayS_MS: When managed code calls an unmanaged function
that is implemented in a DLL, platform invoke locates the DLL that
implements the function, loads the DLL into memory, and locates the
function address in memory.
AjayS_MS: It then pushes the function’s arguments onto
the stack, marshals any data that has to be marshaled, enables pre-emptive
garbage collection, and transfers control to the address of the unmanaged
code.
AjayS_MS: So the basic marshalling overhead applies here
too.
Moderator: (ronaldo) Contd from prev question - I mean performance
difference between COM and .NET assemblies with ADO.NET, the UI can
be windows or WEB.
AjayS_MS: ADO.NET vs ADO don’t have the exact statistics
now.
Moderator: (Manish_MVP) Can you give some references of the custom
attributes to optionally adjust the way the runtime represents managed
and unmanaged in .NET assemblies hosted in COM+?
AjayS_MS: you can specify custom marshaling attributes
by adding a MarshalAsAttribute to the parameters of the function.
You can also use the MarshalAsAttribute with structures. When using
the MarshalAsAttribute with structures.
AjayS_MS: You must also use the StructLayout attribute
to set the native layout of the structure.
KunalS_MS: Since time has run out, we shall not be taking any more
questions today
