Douglas Crockford has a much better explanation: http://javascript.crockford.com/memory/leak.html
from his site:
Microsoft’s Internet Explorer contains a number of leaks, the worst of which is an interaction with JScript. When a DOM object contains a reference to a JavaScript object (such an event handling function), and when that JavaScript object contains a reference to that DOM object, then a cyclic structure is formed. This is not in itself a problem. At such time as there are no other references to the DOM object and the event handler, then the garbage collector (an automatic memory resource manager) will reclaim them both, allowing their space to be reallocated. The JavaScript garbage collector understands about cycles and is not confused by them. Unfortunately, IE’s DOM is not managed by JScript. It has its own memory manager that does not understand about cycles and so gets very confused. As a result, when cycles occur, memory reclamation does not occur. The memory that is not reclaimed is said to have leaked. Over time, this can result in memory starvation. In a memory space full of used cells, the browser starves to death.

You can use these tools to find what is causing the memory leak:
http://home.orange.nl/jsrosman/ (Sieve)
http://blogs.msdn.com/gpde/pages/javascript-memory-leak-detector.aspx (unsupported ms tool)

I’ve used Sieve and it’s worked very well.

Update panels exacerbate this issue because there are an increased number of postbacks causing an increased rate of memory leaks. The greater amount of elements in the leaking update panel, the greater chance you’re leaking more memory.

potentially, adding javascript event handlers via markup or expando attributes will cause this problem e.g. onblur = ‘if(!function()){this.focus();}else{return true;}’ or Page.ClientScript.RegisterExpandoAttribute(ClientID, “evaluationfunction”,”cb_verify”);

Try commenting out columns and/or custom javascript behavior (onclick, onblur, etc.) to see if you can cut down on the memory leaked. The tools listed are a little rough to get your arms around but are very effective when you get them up to speed.

Good luck,

Phil

My GridView is inside an UpdatePanel.

I tried to put the following code in my GridView_OnPreRender and also in the UpdatePanel_OnPreRender but memory usage is still increasing a lot.
# If GridView.Visible Then
# Dim script As String = UpdatePanelRemoveNodeOnPostback.CreateScriptToRemoveExistingNodeFromUpdatePanelBeforePageLoad(GridView)
# Me.Page.ClientScript.RegisterStartupScript(Me.GetType, “RemoveGridViewPrePostBackLoad”, script)
# End If

Do you think I should try to put that bit of code somewhere else in my form? I also tried to create an override PreRender function but still no luck.
I can’t believe how much memory my application uses; it’s ridiculous, if I open my form and perform same changes/transactions on the gridview, in a matter of minutes the memory used by Internet Explorer is over 500MB; it pretty much freezes the client machine and must close and restart IE.
Using Firefox the memory usage still increases, but not even close to what happens with IE. Using Firefox it’s not too bad, but unfortunately I have other “tools” in my page that don’t work on firefox, only on IE.

This is a really critical task for me, I really appreciate your help.
Thanks in advance!

MAURO

you have to write that into your resource file… got it?

Do you have an idea of why this is happening?
My Script is a string that contains the javascript code posted above.

Thanks for your help

Don’t get me started on “AJAX for ASP.NET”…

I’ve settled into prototype.js myself, as it seems to be a bit more flexible.

- dk

But it sounds to me like you’re ready to move beyond the update panel. I say this for multiple reasons but i’ll tell you a couple now. Using a webservice and rendering the results via javascript is going to give you a pretty large performance increase just because you’ll be transmitting less data each round trip. Secondly, everytime i’ve worked with dynamic control creation using the update panel it has not gone well. You need to decide how much work you want to put into this solution, but if you’re looking for something that’s going to scale well and be much more responsive then an update panel, please read on. You should consider constructing a really light weight DTO to push search results back from a webservice and render those results from javascript once the call has completed. It’s really hard for me to guess what your setup is like but here is a little something to get you started.

1) create a really simple class that has all the properties you’ll be passing back from the search, also create a javascript version.
2) Create a simple webservice that you pass search terms it builds and serializes server-side search results and passes them as webservice results in JSON format.
3) Use the ajax control toolkit $common.createElementFromTemplate() method to build your results into fancy mark-up.
http://aspnetresources.com/blog/build_dom_with_toolkit_common_library.aspx
4) You’ll need to hook-up the delete panel event to the newely constructed search results panel, but when that fires you should just be able to remove the whole panel from the DOM and be done with it.

Another Alternative:

ASP.NET AJAX Client Templates
http://quickstarts.asp.net/previews/ajax/

Although, not CTP there may be a much MUCH easier way for you to do this using the asp.net ajax futures preview.
http://www.microsoft.com/downloads/details.aspx?FamilyId=D7101C1A-5993-4F70-9944-4B98F312502D&displaylang=en

Basically what im asking you is: How do i delete an update panel from the DOM?

Thanks for your time, and hope to hear back.
-Chris L

returns a result well over 256 characters:
sysrowsetcolumns,sysrowsets,sysallocunits,sysfiles1,syshobtcolumns,syshobts,sysftinds,sysserefs,sysowners,sysdbreg,sysprivs,sysschobjs,syslogshippers,syscolpars,sysxlgns,sysxsrvs,sysnsobjs,sysusermsgs,syscerts,sysrmtlgns,syslnklgns,sysxprops,sysscalartypes,systypedsubobjs,sysidxstats,sysiscols,sysendpts,syswebmethods,sysbinobjs,sysobjvalues,sysclsobjs,sysrowsetrefs,sysremsvcbinds,sysxmitqueue,sysrts,sysconvgroup,sysdesend,sysdercv,syssingleobjrefs,sysmultiobjrefs,sysdbfiles,sysguidrefs,syschildinsts,sysqnames,sysxmlcomponent,sysxmlfacet,sysxmlplacement,sysobjkeycrypts,sysasymkeys,syssqlguides,sysbinsubobjs,spt_fallback_db,spt_fallback_dev,spt_fallback_usg,QueryNotificationErrorsQueue,queue_messages_1003150619,EventNotificationErrorsQueue,queue_messages_1035150733,ServiceBrokerQueue,queue_messages_1067150847,spt_monitor,spt_values,DF__spt_value__statu__436BFEE3,MSreplication_options,sp_MSrepl_startup,sp_MScleanupmergepublisher

Is it possible your query tools is truncating the result?

select STUFF(
(
SELECT ‘,’ + convert(varchar(12), object_id)
FROM sys.objects
FOR xml PATH(”)
), 1, 1, ”)

Any idea how to resolve this issue? Highly appreciated!

thanks.

Although we use a .bat file for doing the merging and calling YUICompressor (called in our nant files during compilation). Which in reflection, I think you’re use of nant commands is much better (using concat and then calling YUICompressor via nant). Batch files can be a bit fiddly. If I get time I’ll change ours to be similar to yours. Cheers.

During the build (CruiseControl.Net) we get the last svn revision number. Part of the build process involves “tokenising” our .config files (ie Web.config) with environment variables. We pass in the revision number into the config file.

Then when generating the url for the CSS and JavaScript we include the AppSettings key as part of the path, something like “/webresources/javascript/merged.7567.js”. We then have a rewrite rule to point “/webresources/javascript/merged.7567.js” > “/webresources/javascript/merged.js”. So to the browser it requests a url, but IIS points that request to a different file.

We chose not to use a querystring (ie merged.js?version=7567) as this doesn’t follow HTTP guidelines. IE and Firefox will work regardless but I believe Safari and Opera may be stricter.

It’s then just a matter of setting an Expires Header for the JavaScript and CSS, we currently have ours at 20 days.

http://my.huddle.net is the url. Doing some interesting stuff there. RESTful JSON API, Inversion Of Control, Distributed NHibernate Caching, Domain Driven Design etc…