Transformations appear to be CPU intensive

[Keith Chadwick]

I am migrating an existing ASP app that uses XSLT transformations to render against a language XML doc for localization and other items. When I moved this logic into .NET and the native xml and xsl objects I noticed a significant processor hit on the web machine.

The xml file is roughly 110KB and the XSLT files, the called transformation has several includes, is in total about 20KB. I have run the application test center on the page which contains the below code and it seems to indicate resonable response times but the web server CPU in task manager is pegged at 100%. Even individual requests when run via the browser peg the process. I have narrowed it down to transformations as a page that does not contain any transforamtions barely tweaks the processor. Below is the VB code, if I remove the transform line then the page again barely tweaks the CPU in task manager.

Dim objXML As New XmlDataDocument()
objXML.Load(Server.MapPath("shared/x/siteData.xml"))

Dim objXSL As New XslTransform()
objXSL.Load(Server.MapPath("scripts/clnt.home.body.xslt"))
objXSL.Transform(objXML, Nothing, Response.OutputStream)
objXML = Nothing
objXSL = Nothing

Is there a known issue with transformation or is there a better way of doing this. Of interest when I used MSXML4.0 in .NET I did not get this problem even though MS states you should not use it.

Any thought?

Keith Chadwick

PS: I will be using Page caching to reduce the server load but still would like to know whats up?

[Oleg Tkachenko]

Keith Chadwick wrote:

Dim objXML As New XmlDataDocument()
objXML.Load(Server.MapPath("shared/x/siteData.xml"))

Dim objXSL As New XslTransform()
objXSL.Load(Server.MapPath("scripts/clnt.home.body.xslt"))
objXSL.Transform(objXML, Nothing, Response.OutputStream)
objXML = Nothing
objXSL = Nothing

XmlDataDocument is slow for XSLT, use XPathDocument instead - it's much
faster and has lesser memory footprint.
And cache compiled XslTransform, because Load() operation isn't cheap,
but once stylesheet is loaded (hence compiled) you can call its
Transform() method as many times your need and in as many thread you want.
--
Oleg Tkachenko
XML Insider
http://www.tkachenko.com/blog

[Keith Chadwick]

Thanks Oleg,

When you mentioned the cache I assume you mean placing the XslTransform
'object' within the context.cache

cheers
keith

"Oleg Tkachenko" <oleg@NO!SPAM!PLEASEtkachenko.com> wrote in message
news:%2***************@TK2MSFTNGP11.phx.gbl...

Keith Chadwick wrote:

Dim objXML As New XmlDataDocument()
objXML.Load(Server.MapPath("shared/x/siteData.xml"))

Dim objXSL As New XslTransform()
objXSL.Load(Server.MapPath("scripts/clnt.home.body.xslt"))
objXSL.Transform(objXML, Nothing, Response.OutputStream)
objXML = Nothing
objXSL = Nothing

XmlDataDocument is slow for XSLT, use XPathDocument instead - it's much
faster and has lesser memory footprint.
And cache compiled XslTransform, because Load() operation isn't cheap,
but once stylesheet is loaded (hence compiled) you can call its
Transform() method as many times your need and in as many thread you want.
--
Oleg Tkachenko
XML Insider
http://www.tkachenko.com/blog

[Keith Chadwick]

just implemented your suggestion Oleg, bloody brilliant cheers!! much much
better performance.

Keith

"Oleg Tkachenko" <oleg@NO!SPAM!PLEASEtkachenko.com> wrote in message
news:%2***************@TK2MSFTNGP11.phx.gbl...

Keith Chadwick wrote:

Dim objXML As New XmlDataDocument()
objXML.Load(Server.MapPath("shared/x/siteData.xml"))

Dim objXSL As New XslTransform()
objXSL.Load(Server.MapPath("scripts/clnt.home.body.xslt"))
objXSL.Transform(objXML, Nothing, Response.OutputStream)
objXML = Nothing
objXSL = Nothing

XmlDataDocument is slow for XSLT, use XPathDocument instead - it's much
faster and has lesser memory footprint.
And cache compiled XslTransform, because Load() operation isn't cheap,
but once stylesheet is loaded (hence compiled) you can call its
Transform() method as many times your need and in as many thread you want.
--
Oleg Tkachenko
XML Insider
http://www.tkachenko.com/blog

[Oleg Tkachenko]

Keith Chadwick wrote:

When you mentioned the cache I assume you mean placing the XslTransform
'object' within the context.cache

In ASP.NET - exactly, in other environment - by other means.
--
Oleg Tkachenko
XML Insider
http://www.tkachenko.com/blog

[Anders Borum]

> much much better performance.

Ofcourse! :-)

--
venlig hilsen / with regards
anders borum
--