How to create striped disk on azure (AKA Raid 0)

Disk Striping use multiple disks and stripe them together to get a combined higher IOPS and Throughput limit. Note that the combined limit per VM should be higher than the combined limits of attached premium disks.

1. Create “new disk” from powershell:

clear

# RM stands for resource manager, and is the new way of managing things in Azure

# you need to login the first time using this command
# Login-AzureRmAccount

$vm = Get-AzureRmVM -ResourceGroupName "md-test-stripe" -Name "md-test-stripe"

# adds 16 disks
for($i=1; $i -le 16; $i++) {
    $name = "md-test-stripe-disk{0:00}" -f $i
    $lun = $i - 1
    $vhdUri = "https://mdteststripedisks447.blob.core.windows.net/vhds/md-test-stripe-disk{0:00}.vhd" -f $i

    Write-Host "Add-AzureRmVMDataDisk -VM $vm -Name $name -DiskSizeInGB 16 -Lun $lun -Caching None -VhdUri $vhdUri -CreateOption Empty"

    $vm = Add-AzureRmVMDataDisk -VM $vm -Name $name -DiskSizeInGB 16 -Lun $lun -Caching None -VhdUri $vhdUri -CreateOption Empty
}

$vm.DataDiskNames

# uncomment when you are ready, this updates the VM on azure!
# Update-AzureRmVM -ResourceGroupName "md-test-stripe" -VM $vm

2. Create “new storage pool” from server manager with all the new disks you added

3. Create “new virtual disk” from powershell:

New-VirtualDisk -FriendlyName "sql-stripe" -StoragePoolFriendlyName "sql-stripe" -Interleave 65536 -NumberOfColumns 16 -ProvisioningType Fixed -ResiliencySettingName "Simple" -UseMaximumSize

4. Create “new volume” from server manager formatting in NTFS with allocation unit size set to 64KB

Porting from SQLIO to DISKSPD: How to Test Disk Performance for SQL Server

DISKSPD TESTS

Original post related to SQLIO took from brentozar blog.

diskspd -w100 -t8 -d60 -o32 -r -b8K -Sh -L -c20G C:\test.dat
diskspd -w0 -t8 -d60 -o32 -r -b8K -Sh -L -c20G C:\test.dat
diskspd -w100 -t8 -d60 -o32 -si -b64K -Sh -L -c20G C:\test.dat
diskspd -w0 -t8 -d60 -o32 -si -b64K -Sh -L -c20G C:\test.dat

What Do the DISKSPD Parameters Mean?

While we’re looking at that set of commands, here’s a quick breakdown:

  • -w100 and -w0: means we’re testing writes (100% writes) or reads (0% writes).
  • -t8 and -o32: means 8 threads with up to 32 outstanding requests at once.
    DISKSPD isn’t CPU-bound at all, and you can use more threads than you have processors.
    The more load we throw at storage, the faster it goes – to a point.
  • -d60: means the test will last 60 seconds
  • -b8K and -b64K: the size of our IO requests in kilobytes.
    SQL Server does a lot of random stuff in 8KB chunks,
    and we’re also testing sequential stuff in 64KB chunks.
  • -r and -s: random versus sequential access.
    Many queries jump around randomly in the database, whereas things like backups,
    bulk loads, and table scans generally work sequentially.
  • -L: measure latency statistics.
  • -Sh: equivalent -Suw, disable software caching, equivalent to FILE_FLAG_NO_BUFFERING and enable writethrough (no hardware write caching), equivalent to FILE_FLAG_WRITE_THROUGH.
  • -c20G: create a file of 20GB. Size can be stated in bytes or KiB/MiB/GiB/blocks.

You’ll notice I’m using a lot of general terms here about how some application patterns work.
Every SQL Server database has its own access patterns – random, sequential, big chunks, small pieces, and so on.
The four test lines you see above are shorthand examples of how some SQL Server IO patterns work.
We’re going to run a quick 4-part test first, and then come back to run much more in-depth tests shortly.

Powershell Commands for Visual Studio Team Services (VSTS, AKA VSO)

For instance you can set a variable like this:

Examples:

##vsotask.setvariable variable=testvar;]testvalue
##vso[task.setvariable variable=testvar;issecret=true;]testvalue

in powershell:

Write-Host "##vso[task.setvariable variable=testvar;]testvalue"

Here’s the complete list:

https://github.com/Microsoft/vsts-tasks/blob/master/docs/authoring/commands.md

Happy scripting!

How to Debug the Design Time Errors in WPF XAML File?

[Reblogged from How to Debug the Design Time Errors in WPF XAML File? thanks to Manish Dubeyy]

Introduction

While developing WPF applications, design view plays an important role not only placing the controls but also we can see the run time view at design time. How does it look like? It becomes frustrating when we see some design time errors and we cannot put a break point in XAML file to diagnose the error, moreover due to this single error sometimes, whole designer fails rendering other controls. So this article enables us to debug the design view of XAML documents in WPF.

Background

It is a pre-requisite that one should be familiar with basic WPF and most importantly one should know how to set design time data context. You can refer to other articles on CodeProject to know how to set a design time data context like this one.

Problem

While designing WPF applications, we frequently see the following types of error in our design view (See pic). Since XAML code does not allow us to insert a break point and debug the stuff, I will share a small trick to trap this error. (References are already there on the internet, but still developers are not so habituated to using it. The reason is that most of them don’t know it.)

ErrorPreview

Steps To Debug the Design Time Errors

  1. First of all, close all opened XAML documents in Visual Studio.
  2. Open the new instance of the same application in Visual Studio (say app2).
  3. Again, close all opened XAML documents. (To be on the safe side, you may close all documents in app2).
  4. Now open Task Manager just to verify whether XDesProc.exe must not be running. (Basically XDesProc.exeis responsible for debugging XAML files, so if any XAML documents are opened, then it launches automatically). So, if you find that XDesProc.exe is running (in Processes Tab), just kill it (right click on process and click on End Process Tree option).
  5. Now switch to app1 (original instance of Visual Studio in which you want break point to be hit). Now, open the file containing the design data view model (MainWindowViewModelDesignData.cs) and place a break point in the first line of its constructor.
  6. Switch to app2 again and open the View (i.e. MainWindow.xaml in which design time error is raising). It will launch the XDesProc.exe in Task Manager.
  7. Switch to app1 again, and go to Debug -> Attach to Processes… context menu item in Menu bar of Visual Studio.
  8. Search the XDesProc.exe and click on attach button.
  9. Switch to app2 and close and reopen the same XAML document (MainWindow.xaml). Once you do it, break point will get hit!2-Solve
  10. Here, you will find that you have not instantiated the PersonList property which is causingNullReference Exception in WPF Designer. After fixing it, you will see that now the designer is showing the data as well.3-DesignView

Points of Interest

For Visual Studio 2010 users, you will find devenv.exe in place of XDesProc.exe. Also, you can tweak with the exception settings if your break point does not becomes active (i.e., Go to Debug -> Exceptions settings -> Common Language RunTime Exceptions).

License

This article, along with any associated source code and files, is licensed under The Code Project Open License (CPOL)

WPF Design Time Resources Dictionary

[Reblogged from WPF Design Time Support (Part 2) thanks to jbe2277]

The WPF Designer works best if there is just one WPF project in the solution which is the application (exe) and so contains the App.xaml file. Then it will find all XAML resources that are necessary to render the views flawlessly. But in larger applications the views are often separated into different WPF projects (e.g. per module). In such a scenario the WPF designer is not able to find the resources defined or referenced in App.xaml anymore when this file resides in another project.

Microsoft introduced the Design-time Resources Dictionary file to overcome this issue. Blend is able to detect that some resources could not be resolved and asks us if we want to add a resource dictionary to use for displaying resources at design time.

blend-designtimeresources

Visual Studio uses this file as well but it is not able to create the file. If you want to create this file in Visual Studio then you have to create a Resource Dictionary (WPF). Use DesignTimeResources.xaml as file name and after creation move the file into the Properties folder in your project tree.

Now unload the project (Context menu of the project node in Solution Explorer). Then select Edit YourProject.csproj in the context menu of the unloaded project node. Search for the XML element that contains DesignTimeResources.xaml and replace it with the following XML snippet:

<Page Include="Properties\DesignTimeResources.xaml" Condition="'$(DesignTime)'=='true' OR ('$(SolutionPath)'!='' AND Exists('$(SolutionPath)') AND '$(BuildingInsideVisualStudio)'!='true' AND '$(BuildingInsideExpressionBlend)'!='true')">
  <Generator>MSBuild:Compile</Generator>
  <SubType>Designer</SubType>
  <ContainsDesignTimeResources>true</ContainsDesignTimeResources>
</Page>

Reload the project. The DesignTimeResource dictionary can be filled with MergedDictionaries. In the following example the merged dictionaries reside in another assembly. Thus, the long Source path is used.

<ResourceDictionary
    xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation" 
    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml">

    <ResourceDictionary.MergedDictionaries>
        <ResourceDictionary Source="/Waf.InformationManager.Common.Presentation;Component/Resources/ImageResources.xaml"/>
        <ResourceDictionary Source="/Waf.InformationManager.Common.Presentation;Component/Resources/ConverterResources.xaml"/>

This file will be ignored by the compiler. It does not have any effects on the running application. It is just used to improve the design time experience.

EF6.x Correlating Poor Performing SQL to Application Code

romiller.com

When using an O/RM, poor performing SQL statements are often not discovered until you (or your DBA) find that a particular query is slowing down your database server. At this point, it becomes hard to identify which piece of application code is causing that SQL to be executed.

An interceptor to log slow/failed SQL

In EF6.0.0 we introduced interceptors, which allow you to get into the pipeline just before, and just after, a query/command is sent to the database.

Here is an interceptor that detects queries/commands that either failed, or exceeded a chosen threshold for execution time. In addition to the query being executed, it logs the call stack. This allows us to identify which piece of our application code initiated the database operation.

This example writes to a log file, but you can log the information to wherever needed.

Registering the interceptor

The easiest way to get our…

View original post 133 more words

Entity Framework validation with partial updates

I had this issue today, basically Entity Framework always validate all the entity, so if you want to make a partial update using Attach/Entity State way, you can’t do it if you have configured validation on your model and you don’t fill all your entity with good values, but we want to do a partial update without do another query before, and also without filling up all the entity with data I don’t have, so how to do it?

The most easiest and fastest way is to completely disable the validation for your operation, but this is not the ideal way, what about validating the property I’m near to udpate?

using (var db = new NorthwindDbContext())
{
    // disable the validation for this operation
    db.Configuration.ValidateOnSaveEnabled = false;

    var customer = new Customer
    {
        CustomerId = "ALFKI"
    };
    db.Customers.Attach(customer);

    customer.PostalCode = "123456789000";

    // throw sql exception because PostalCode goes over 10 chars maximum
    // String or binary data would be truncated.
    await db.SaveChangesAsync();
}

Thanks to Shimmy I found what I think is the most elegant solution:

protected override DbEntityValidationResult ValidateEntity(DbEntityEntry entityEntry, IDictionary<object, object> items)
{
    var result = base.ValidateEntity(entityEntry, items);

    var falseErrors = result.ValidationErrors
                            .Where(error =>
                            {
                                if (entityEntry.State != EntityState.Modified) return false;
                                var member = entityEntry.Member(error.PropertyName);
                                var property = member as DbPropertyEntry;
                                if (property != null) return !property.IsModified;
                                return false;
                            });

    foreach (var error in falseErrors.ToArray())
    {
        result.ValidationErrors.Remove(error);
    }

    return result;
}

To the Shimmy sample I’ve added the condition “if (entityEntry.State != EntityState.Modified) return false;” to avoid bypass the validation when adding an entity.

Now if you test the same code as before, you will receive an entity framework exception and no round-trip will be made on sql server:

using (var db = new NorthwindDbContext())
{
    var customer = new Customer
    {
        CustomerId = "ALFKI"
    };
    db.Customers.Attach(customer);

    customer.PostalCode = "123456789000";

    // Validation failed for one or more entities. See 'EntityValidationErrors' property for more details.
    // The field PostalCode must be a string or array type with a maximum length of '10'.
    await db.SaveChangesAsync();
}