Error TF255271 while upgrading TFS 2005 -> 2010

When upgrading TFS 2005 to TFS 2010 (using these instructions) and it worked great on my test computer, but when I went to migrate the production server, I received the following error:

Warning Message: [2011-05-12 20:12:14Z] Servicing step Register Integration Database failed. (ServicingOperation: UpgradePreTfs2010Databases; Step group: AttachPreTFS2010Databases.TfsFramework)
Warning Message: TF255271: The team project collection could not be created. The number of steps before the completion of project creation is: 216. The number of steps completed before the failure was 10.

The error message doesn’t give any detail at all, so I opened the log file and found this near the bottom:

[Info   @20:12:19.133] [2011-05-12 20:12:14Z][Error] BisCreateSchema.sql Line 816 Error: Incorrect syntax near ‘,’. (10 of 216)
[Info   @20:12:19.133] [2011-05-12 20:12:14Z][Informational] Microsoft.TeamFoundation.Framework.Server.CollectionServicingException: BisCreateSchema.sql Line 816 Error: Incorrect syntax near ‘,’.
—> System.Data.SqlClient.SqlException: Incorrect syntax near ‘,’.

Try as I might, I couldn’t find the SQL file it referred to, and Google wasn’t much help either – however, it seemed that the SQL file wasn’t actually to blame, especially since the same upgrade process had run flawlessly on my test server a few days earlier. Then I realized that my test server was SQL 2008 and my production server was SQL 2005 – while I didn’t read specifically anywhere that this was a problem, SQL 2005 isn’t supported by TFS 2010.

After much digging, the cause of the error ends up being that the TFS upgrade tool (and TFS 2010 in general) doesn’t support SQL Server 2005. Upgrading the database server to SQL Server 2008 and re-running the process corrected the error and allowed us to complete the migration.

However, I’ve read that SQL 2008 support on TFS 2005 is patchy, so this also obliterates your rollback, if you were planning on one 🙂 If you get this error, hope this helps!

Lightweight, single-row alternative to OUTPUT clause in T-SQL

SQL Server 2005 adds the option for an OUTPUT clause in your query to act upon table rows and return the old and new values. When I’ve done queuing in the past, I’ve used the clause to mark a row as processing and return the value, all in a single operation, so it’s lightweight and threadsafe. For example, like this:

UPDATE TOP (1) dbo.MyQueue
   SET ClaimedBy = @Server,
       ClaimTime = @ClaimTime
  INTO #OutputTable (QueueID, Column1, Column2, Column3)
 WHERE Some Criteria...

To do this, you’ll need to create a table called #OutputTable that has the right schema, which works well if you’re returning multiple rows from your query, but is a little cumbersome to work with if you’re only doing one row at a time. If you’re only returning a single row from your UPDATE query (as I am here), there’s an alternative to OUTPUT that’s easier to use – just do variable assignment inline in the UPDATE statement! The query above becomes:

UPDATE TOP (1) dbo.MyQueue
   SET ClaimedBy = @Server,
       ClaimTime = @ClaimTime
       @QueueID = QueueID,
       @OutputVar1 = SomeData1,
       @OutputVar2 = SomeData2,
       @OutputVar3 = SomeData3
 WHERE Some Criteria...

Notice the reversed variable assignment in the second query? I’ve done away with my table, and my OUTPUT clause, and now I just have the relevant values from the row I’m interested in. Much easier to work with, and as an added bonus (though I hope you’re not in this situation), it works just fine in SQL 2000.

The caveat is that it’s only good for a single row, and it only works for UPDATE – if you’re using DELETE, you’ll still need the temp table and an OUTPUT clause.

Reading from C:\ProgramData without requiring UAC elevation

When trying to read some user settings from C:\ProgramData in my .NET app, I was getting an Access Denied exception, even though I was only attempting to read the configuration file, not write anything:

System.UnauthorizedAccessException: Access to the path ‘C:\ProgramData\YourApp\\settings.xml’ is denied.

Even though I was only reading the file, and not writing anything, it still wanted elevation before it let me read it. It turns out that I need to signify my intent not to write anything when I open the stream. This code generated the exception (the “Using” statement actually threw the exception):

Using f As New FileStream(MySettingsFilePath, FileMode.Open)
    Dim formatter As New Formatters.Binary.BinaryFormatter
    MySettings = formatter.Deserialize(f)
End Using

However, by changing the “FileStream” to a “StreamReader”, I signify my intent to read and not write, so the code runs without an issue (there are two changes):

Using f As New StreamReader(MySettingsFilePath)
    Dim formatter As New Formatters.Binary.BinaryFormatter
    MySettings = formatter.Deserialize(f.BaseStream)
End Using
MORAL – Elevation isn’t required to read common application settings, only to write them, but you need to be clear about what you intend to do!

Periodic timeouts with local WCF endpoint

I have two applications – a Windows service and a client WinForm – that run on the same box, and the client needs to check on the status of the service every few seconds. It worked well most of the time, but every 4-5 times, it would timeout – I’d receive a System.TimeoutException, no matter how long the timeout was actually set for. It didn’t make sense – the two apps are on the same box, it happens with both a TCP and an NamedPipe endpoint, and it can happen even when the service isn’t busy.

It turns out that WCF endpoints only handle a very limited number of simultanious connections, and though I was creating a new ChannelFactory each time, I wasn’t closing the channel when I was finished with it. I assumed that it would automatically close the channel when it passed out of scope, but no dice. Since the channels remained open, it didn’t take long to fill them all up, and then the app would appear to be unresponsive until my channels started to time out. So here’s what I ended up doing – critical line in bold, at the end:

Dim tcpBinding As New NetTcpBinding
Dim pipeFactory As ChannelFactory(Of WCF_Class.IServiceRemoting) = New  _
    ChannelFactory(Of WCF_Class.IServiceRemoting)(tcpBinding, "net.tcp://localhost:4079")
Dim ServiceWCFConnection As WCF_Class.IServiceRemoting = pipeFactory.CreateChannel
pipeFactory.Close() ' This is what's important!

That’s it – make sure you close your Channel when you’re done with it! If you leave it open, you quickly hit the server’s connection limit and new requests will fail. Closing the channel when you’re done frees it up, instead of letting it time out and close on its own.

Removing an arbitrary number of spaces from a string in SQL Server

When I was concatenating some fields to create an address, I ended up with a number of spaces in my address that were unnecessary. For example, I had this:

SELECT StreetNumber + ' ' + Direction + ' ' + StreetName + ' ' + StreetType as Address

However, when an address didn’t have a direction, I ended up with a double-space in the middle of my address, and I wanted a way to clean it up. Enter the code I found at

SELECT name,
       REPLACE(REPLACE(REPLACE(name,' ','<>'),'><',''),'<>',' ')
  FROM SomeTable

This shortens any run of spaces in the string into a single space – sneaky! It works in any language that supports a function like REPLACE, which scans one string for instances of a second string, and swaps them out for something else.