.NET Tutorials, Forums, Interview Questions And Answers
Welcome :Guest
Sign In
Win Surprise Gifts!!!

Top 5 Contributors of the Month
Gaurav Pal
Post New Web Links

Trying to read PerformanceCounter getting : Could not read Category Index ####

Posted By:      Posted Date: April 10, 2011    Points: 0   Category :WPF
We have a monitoring application that along with other things monitors PerfCounters on various servers.
The application spawns multiple processes to execute the monitoring tasks. One of the monitoring tasks is to collect PerfCounter data from remote machines using the System.Diagnostics.PerformanceCounter class. The code seems to work fine for the most part but intermittently fails with the following error
            Could not read Category Index ####

We verified that the systems being monitored are not clusters (with active/passive nodes failing over etc). Also these counters are standard Exchange or SQL counters that should not be changing on the machine.
I read this post about some caching that the .net framework does under the cover that may be related but not sure.
Any pointers that you might have on this would be very helpful.

View Complete Post

More Related Resource Links

If the index write count is more than index read count should it be dropped ?

If the index write count is more than index read count should it be dropped ?   i am using this query to see thank you for all answers SELECT object_name(s.object_id) AS 'Table Name', i.name AS 'Index Name', i.index_id, user_updates AS 'Total Writes', user_seeks + user_scans + user_lookups AS 'Total Reads', user_updates - (user_seeks + user_scans + user_lookups) AS 'Difference' FROM sys.dm_db_index_usage_stats AS s WITH (NOLOCK) INNER JOIN sys.indexes AS i WITH (NOLOCK) ON s.object_id = i.object_id AND i.index_id = s.index_id WHERE objectproperty(s.object_id,'IsUserTable') = 1 AND s.database_id = db_id() AND user_updates > (user_seeks + user_scans + user_lookups) AND i.index_id > 1 ORDER BY 'Difference' DESC, 'Total Writes' DESC, 'Total Reads' ASC;     and here sample result please comment it for me   http://img688.imageshack.us/img688/527/indexim.png  Best of Pokemon Games PokemonCraft Developer Used URL rewriting at it's Pokedex

How to read Search index using SQL



Where does the search index data get stored in sharepoint ? Is it in the index file location or in the SQL database ? Is it possible to read the index data using SQL queries ?

Serial Port Communication Read and Write using C#.net

In this simple article you will learn that how you can Open and read COM port data using System.IO.Ports Namespace.
Simply just create New Project of windows application in C#.

Import ServiceProcess APIs
using System.IO.Ports

Imports System.IO.Ports

Write Parsing functions which parse port data according to attached device

Scripts not read when in head tag


I just upgraded to VS2010 if that matters.  I'm learning JQuery and noticed that scripts don't work if they're in the head tag.  Also, I need the script tag with type="text/javascript" in the head (with nothing else) in order for the JQuery scripts in the body to work.

Very bizzare, any suggestions?

With a separate script tag in the <body> with my JQuery script, this works

<head runat="server">
<script type="text/javascript" src="http://ajax.googleapis.com/ajax/libs/jquery/1.4.2/jquery.min.js" />
<script type="text/javascript">

This doesn't:

<head runat="server">
<script type="text/javascript" src="http://ajax.googleapis.com/ajax/libs/jquery/1.4.2/jquery.min.js" />

I am not able to read xml file with XDocument if its Descendants has Attribute xmlns="http://abc.co


I am not able to read xml file with XDocument if its Descendants has  Attribute like:-

<?xml version="1.0" encoding="utf-8" standalone="yes"?>
  <row ID="1" xmlns="http://www.opentravela.org/OTA/2003/05">
    <var country_name="Caribbean and Rest of the world" city_name="Kingston" flight_category="Economy Class" via="Atlanta" flight_departure="London Heathrow" airline_logo="Delta" adult_fare="Delta" child_fare="660" infant_fare="561" date1="132" date2="2010-08-15" />


I don't know what to do ?

Looking for some help..

How to read XML using LINQ in VB.NET


Can someone please tell me (sample code) how to read this XML into a SQL DB?  Should I use LINQ to XML?  Does anyone have any sample code?  I am working in VB.NET


<?xml version="1.0" encoding="utf-8"?>

<ReadOrderResponseType xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:xsd="http://www.w3.org/2001/XMLSchema">

<Status xmlns="urn:mysol:apis">Success</Status>

<TimeStamp xmlns="urn:mysol:apis">2010-07-25T15:26:49.1150235Z</TimeStamp>

<StoreUrl xmlns="urn:mysol:apis">http://xyz.COM</StoreUrl>

<PageResponse xmlns="urn:mysol:apis">




Read Excel file from Web Application (C#)



I have a web app where user uploads a file.

File is saved in server locally and I want to read some data from it.

Currently my development  server has office 2003.

So do I need office 2007 in order to be able to  read an excel from office 2007 ?

What are other requirements  ?

I tried a test, using

Microsoft.Office.Interop.Excel.Application excelApp = new Microsoft.Office.Interop.Excel.Application();
Microsoft.Office.Interop.Excel.Workbook wrkBook; // = new Microsoft.Office.Interop.Excel.Workbook();

wrkBook = excelApp.Workbooks.Open(@"C:\www\excel_files\b.xls", ....);

But When trying to open the file I get the error:

Exception from HRESULT: 0x800A03EC

So I'm wondering what I'm missing.


How to read value of CheckBox in EXCEL sheet


I am using OLEDBConnection (@"Provider=Microsoft.ACE.OLEDB.12.0;") to connect to the EXCEL file and read contents. When I read the contents, I get all the contents from the excel sheet but i dont get contents for checkboxes placed inside.

My Excel sheet contains set of checkboxes and I need to know If they are checked or not.These checkboxes are controls which are added from Developer tab in EXCEL.

I dont want to use Excel Assemblies for reading contents as it is not recommended. And also i am using OLEDBconnection and want to stick to this .

Awaiting replies from you guys. Thanks in Advance.

How to read Excel table?


If I  use Microsoft.Jet.OLEDB.4.0 to retreive for example named range or sheet from Excel and use it as data source for some server control on the ASP page, everything works fine. But when I try to get table from Excel like this: "select * from [Table1]", debugger complains that database engine could not find object Table1. So how should I reference Table1 in Excel file so that the database engine could find it?

How to read the custom http header



I have just joined the forum. I have a very simple query. I have added custom header to my website. Now I want to read the custom header. I am using IIS 6.0 on windows XP. I have already tried using using the Request.ServerVariables and and Request.header method. But none of them give me the custom header added to website.

Can any body help?

Thanks a lot in advance



Can't read global resource in asp button


I have translated Text Ok in arabic and I have that placed in global Navig.resx file

<asp:Button ID

Crystal Report gives System.AccessViolationException: Attempted to read or write protected memory. T


when a crystal report for same id is opened again at same time or refreshed then it gives the

"System.AccessViolationException: Attempted to read or write protected memory. This is often an indication that other memory is corrupt."

Stack Trace is :-

Stack Trace:

[AccessViolationException: Attempted to read or write protected memory. This is often an indication that other memory is corrupt.]
CrystalDecisions.ReportAppServer.Controllers.DatabaseControllerClass.SetConnectionInfos(ConnectionInfos ConnectionInfos) +0
CrystalDecisions.CrystalReports.Engine.Table.ApplyLogOnInfo(TableLogOnInfo logonInfo) +362
CrystalDecisions.CrystalReports.Engine.ReportDocument.SetTableLogon(Tables tables, String user, String password, String server, String database, Boolean ignoreCase) +258
CrystalDecisions.CrystalReports.Engine.ReportDocument.SetDatabaseLogon(String user, String password, String server, String database, Boolean ignoreCase) +204

How to create a read only accessor


I have created getter setters before. But how do I make a read only accessor in VB.net? I want a value to be read, but not to be set. 

how read write cookies in asp.net


hi please give me code for read write cookies in  asp.net



error in MicrosoftAjax.js: Cannot read property '_notified' of null


I am cross testing my project with multiple browsers: IE7, Firefox and Chrome.

One one page I have a dynamically built table with two DropDownLists and CascadingDropDown extenders. Maybe the only thing special about the drop down lists is, that I add a "onChange" for the second drop down list in each row which shows or hides the list depending on the value populated from the web services.

All of this works perfectly in IE7 and Firefox, but Chrome does not execute the JavaScript in the onChange attribute and the error console says:

Uncaught TypeError: Cannot read property '_notified' of null

cannot currently modify this text in the editor.It is read only error


Hi, perhaps i have found a bug in Visual Studio 2008 Team Edition.Every thing was going well.

I started to build my project, but for certain reasons i went to Built Tab and while the project wes in build process i clicked Cancel Button.

Alas!! after that my class file has gone to non-editable mode.It is giving this error:

"cannot currently modify this text in the editor.It is read only ".I closed and again opened Project but no improvement.I went to Tool->Import Export Setting->reset all settings but no benefit.

How to resolve this problem ?

Linq2Sql error: "Invalid attempt to call Read when reader is closed."


I've read up on this error from other posts and on other sites, but haven't found a solid resolution to the issue yet. My setup is as follows:

I have a RepositoryBase class that fields certain db calls that all repositories need to perform. In one such call, "GetSecurityGroup", it works most of the time, but will seemingly at random throw an exception with the error "Invalid attempt to call Read when reader is closed." All other Repository classes inherit from this one, and they all use the same DataContext object, which I understand isn't thread safe. Since there could be multiple calls to the DataContext object on the same page, perhaps one is using the DataContext when the next tries to do so. I'm not sure. What can I do to ensure this doesn't happen?

ASP.NetWindows Application  .NET Framework  C#  VB.Net  ADO.Net  
Sql Server  SharePoint  Silverlight  Others  All   

Hall of Fame    Twitter   Terms of Service    Privacy Policy    Contact Us    Archives   Tell A Friend