FOR XML PATH Pivot Columns as Key Value Pairs defeating the "must not come after a non-attribute-centric sibling in XML hierarchy in FOR XML PATH" error

Yesterday I had been working in SQL to create an xml document from a query I needed to make key value pairs out of my column list using one attribute as the key and the element content as the value. Pretty common pattern in XML right? I am aware of and have used the PIVOT key word however using it to describe what I am doing here seemed like the best choice of overloaded term. After several of failed attempts and some googling I threw the following query below into the management studio and finally got the output I had been looking for. The solution? simply add a '' between your elements telling sql server that you have a whitespace value between the two elements.

Windows AppFabric Installation Error 1603

Recently I re-installed and upgraded my local workstation to Windows 8.1 shortly after I installed Windows App Fabric and received error 1603. I heart this error code it says so little and means so much. After looking at the detailed error logs I see that the Hosting Services and Cache Services failed to install. The log file in fun log file fashion references another log file that contains the output of the MSI package that actually failed. Within that log file you may see something that looks like this:

Get-Content : The term 'Get-Content' is not recognized as the name of a 
Error: cmdlet, function, script file, or operable program. Check the spelling of the 

Balderdash you say how could a CmdLet so core to powershell not be present during an installation running in administrative mode? The answer.. you for got to say Simon says or in other words Set-ExecutionPolicy RemoteSigned. In short set the remote execution policy of the powershell console you will be installing. Make sure to set it in both the 32bit and 64bit powershell console to be safe. It should also be noted that error 1603 can mean a variety of different things so make sure your logged conditions apply.

Transaction was deadlocked on resources with another process and has been chosen as the deadlock victim on page and primary key using Microsoft Sql Server

Background

There are many possibilities for deadlocks to occur, this post specifically covers a condition I encountered where a table primary key and page lock on the same table created a deadlock error. I am not going to go into the specifics of troubleshooting deadlocks chances are if you have made it here you already know about using SQL Server Profiler. Deadlocks occur when two pid's are trying to use each others locked object at the same time. The most common cause I have encountered for deadlocks is timing, the longer the transaction or operation the higher the risk that another concurrent operation will create a deadlock situation.

Example

I encountered the deadlock below when a new table in the system began to grow quickly. The table in question was used in frequent and concurrent read/write operations. This situation is probably one that is frequently encountered and the solution in my case turned out to be very simple. Figure A can be distilled to the following sql:

CREATE TABLE A
(
 Id int IDENTITY PRIMARY KEY
)
CREATE TABLE B
(
 Id int IDENTITY PRIMARY KEY,
 AId int FOREIGN KEY REFERENCES A(Id)
)
CREATE TABLE C
(
 Id int IDENTITY PRIMARY KEY,
 BId int FOREIGN KEY REFERENCES B(Id)
)
CREATE TABLE D
(
 Id int IDENTITY PRIMARY KEY
 AId int FOREIGN KEY REFERENCES A(Id),
 CId int FOREIGN KEY REFERENCES C(Id),
)
//Insert some record into A,B,C,D ...//

//Left oval in figure A This is the deadlock victim//
DELETE B WHERE Id=1

//Right oval in figure B//
DELETE C WHERE Id=1

Explanation

You might have expected the statements above to contain a delete cascade option there aren't any. If you are looking for indexes on any there would only be the primary key created by SQL server. Which leads me to the root cause of this issue, table D grew to 500K+ rows which is about where the adventure began. As I mentioned earlier the common cause I have encountered... timing or bad timing in this case. The deletes in table B and table C were conflicting because none of the foreign keys had indexes on them making the constraint checks take longer leaving more time for deadlock to occur. After adding the following indexes the deadlocks were immediately resolved:

CREATE INDEX IX_D_TO_A_FK ON D
(
AId
)
CREATE INDEX IX_D_TO_C_FK ON D
(
CId
)

Safari Webkit IOS6 and Brightness

Apple putting the bright in brightness

While working on an HTML5 application I decided to get fancy and use the webkit brightness effect. This worked great in chrome and even firefox but when testing in Safari something wasn't quite right. Apparently apple decided to implement the brightness function in a little different than the W3C specification. In Safari brightness is a scale -1 0 +1 where 0 is normal and -1 is completely black, the spec calls for 0 as black and 1 to be normal which.

-webkit-filter: brightness(0);

Windows Azure using git deployment with two different websites in the same repository

Excited about the Windows Azure git deployment feature I decided to give it a try with bitbucket. Wow, talk about dead simple invisible magic deployment, I was very surprised at how easy it was. The only hangup is that the process is only designed to handle a single site deployment, if you have more than one web project and/or solution it's time to roll up your sleeves and read some dudes blog.

The git deployment uses a project called kudu that executes when a deployment is triggered by the git repository service of your choice. The process runs a series of shell commands to script and execute the deployment. While looking for a solution I came across an article that explained how to deploy two sites one nodejs the other mvc4 using a conditional batch file. It is just as easy to use this same method for two or more sites deployments using app setting keys to negate any conditional logic, thus turning your deploy.cmd into one line of sweet deployment victory.

Try it your self using the following steps:

1. In the windows azure portal select the website you want to include.
2. Select the configuration tab
3. Scroll Down to app settings
4. Use the Key APPLICATION then enter the name of the application you will use this later
5. Repeat steps 1-4 for the 2nd website you will be deploying
6. On your local computer open a git prompt:

   npm install azure-cli -g

   You are running windows aren't you, that's ok the git prompt is a little bashful.
7. This is going to install all kinds of azure magic, go get beverage and come back or stay and watch the console light show
8. Now from your solution root:

   azure site deploymentscript --aspWAP {Relative Path To Your 1st Project}.csproj -s {Relative Path To Your Solution}.sln
   cp deploy.cmd {Application Name Used in 1st Azure App Settings}.cmd
   azure site deploymentscript --aspWAP {Relative Path To Your 2nd Project}.csproj -s {Relative Path To Your Solution}.sln
   cp deploy.cmd {Application Name Used in 2nd Azure App Settings}.cmd
   

9. Now edit your deploy.cmd to look like this:

   @ECHO OFF
   %APPLICATION%.cmd
   

   Yes.. it's that easy!
10. Commit your changes
11. Check to see if they deployed in the azure portal deployments tab

A simple cross browser JQuery console logging framework JLoggins

Cross browser logging with JQuery

A couple of months ago I tried to find a simple logging framework for JQuery and the browser console. I wanted something simple that supported logging levels and could be easily dropped in to assist in debugging complicated call stacks. I came across some libraries and example code but, I wasn't finding exactly what I was looking for. As a result I decided to put together JLoggins. I have had the code posted for several months on Google code but since JQuery has finally standardized on Github I re-posted it.

Deleting logs with PowerShell and Scheduled Tasks making the mundane a little less painful

This is a new take on an age old problem purging or rotating outdated logging information from servers and workstations alike. I am sure there are hundreds if not thousands of batch files and PowerShell scripts that delete old log files, but what if someone wrote one that not only deletes the old files but is also self aware. Ok.. Maybe not self aware and a far cry from Skynet, but how about one that allows you to schedule and un-schedule it self using the provided parameters as a Windows Scheduled Task.

Well look no further someone has; drop the snippet below into a file called Delete-Logs.ps1 and you too can delete all the things with ease. I have tested this script with Windows 7 and Server 2008 using PowerShell 2.0. While researching I discovered there are also some convenience cmdlets for task scheduler allowing you to manage tasks however, for compatibility reasons I decided stick with schtasks.exe. You will notice I had to remove the path characters from the task name :.(. I had to remove them because of a bug limiting special characters from the scheduled task name.

# Parameters
# -Path A valid absolute path to a log folder or collection of folders script will recursively scan folders
# -Include A wildcard pattern used to include files for consideration 
# -Days Number of days before deleting file from folder
# -Schedule Creates a scheduled task using the provided path, include, and days parameter. Task will run as system user and execute every night at 12:00 AM every 
#  number of days provided in days parameter
# -Unschedule Removes scheduled task that was previously configured for the provided path
# Examples
# Run as stand alone
# .\Delete-Logs.ps1 -Path:'D:\Logs' -Days:4
# Schedule Windows Task
# .\Delete-Logs.ps1 -Path:'C:\Temp' -Include:'*.tmp' -Days:7 -Schedule
# Unschedule Windows Task
# .\Delete-Logs.ps1 -Path:'C:\Temp' -Include:'*.tmp' -Days:7 -Unschedule
Param ($Path='C:\Logs',[string]$Include='*.log', [int]$Days=30, [switch]$Schedule,[switch]$Unschedule)
$Path = New-Object PSObject -Property:@{ Value = $Path; Name = $($Path -replace '\:\\|\\',' ')}
if($Schedule)
{
 Invoke-Expression "C:\Windows\System32\schtasks.exe /create /tr `"`"$PSHome\powershell.exe`" -File '`"'$($MyInvocation.MyCommand.Path)'`"' -Path '`"'$($Path.Value)'`"' -Include '`"'$Include'`"' -Days $Days`" /tn `"Rotate $($Path.Name) every $Days days`" /sc daily /mo $Days /st 00:00 /ru SYSTEM"
}
elseif($Unschedule)
{
 Invoke-Expression "C:\Windows\System32\schtasks.exe /delete /tn `"Rotate $($Path.Name) every $Days days`" /F" 
}
else
{
 $count = 0;
 $start = Get-Date;
 Write-Host "Begin log rotation of $($Path.Value) at $start"
 Get-ChildItem $($Path.Value) -Recurse -Include:$Include | Where-Object {($_.CreationTime -le $(Get-Date).AddDays(-$Days))} | ForEach-Object {
  $date = Get-Date;
  $age = $date.ticks - $_.CreationTime.ticks;
  $age = New-Object -TypeName:'TimeSpan' -ArgumentList:$age;
  Write-Host "Rotating $_ at $date file was $age old";
  Remove-Item $_ -Force;
  $count++;
 }
 $end = Get-Date;
 $duration = $end - $start
 Write-Host "End log rotation of $($Path.Value) at $end $count file(s) were rotated in $duration"
}