Saturday, March 13, 2010

Droid Gmail not synchronizing

For the past 24 hours I've not been receiving new Gmail on my Droid. All of the other apps were still working, even Google Calendar and Contacts. But not the Gmail app.

Manual synchronization didn't work. I deactivated synchronization, turned phone off and on, removed battery. Still no new mail. Looked at the items with the Outbox label and noticed an item, which had a photo attachment, from the day before. I tried to send it and 'No Connection' was the message that I received. Deleted it and new mail started appearing on my phone.

It appears that there was an 'unresolved' item that hadn't been reconciled with the server. This was probably partially my fault because I had tried to send the message from a parking garage, and as soon as I sent the message I deleted the photo from my phone. It was the perfect storm as far as my phone was concerned.

Tuesday, March 9, 2010

Linked Oracle Server configuration pain

For the past day I've been forcing myself to work with the Visual Studio Team System 2008 Database Edition GDR R2 for a small SQL Server 2000 database that needs some attention. I wanted Visual Studio to generate a SQL Server 2005 deployment script that I could execute against a local SQL Server 2008 Express instance in order to test a possible migration. During the initial execution of the script I was notified of an error involving a linked Oracle server. No problem, I thought. I'll just create the linked server and run the script again. As happens so often in software development, though, a seemingly quick and easy task turns into a quagmire.

It's been a while since I set up a linked server and I was a little foggy on the setup steps. I was able to determine by examining the existing SQL Server 2000 server that I needed to use the 'Microsoft OLE DB Provider for Oracle' provider. Still using the existing server, I was able to figure out how to fill in the 'Linked Server Properties' dialog and the Security options. As soon as I clicked the OK button, though, I was presented with an error:

The Oracle client and networking components were not found. These components are supplied by Oracle Corporation and are part of the Oracle Version 7.3 (or greater) client software installation.

OK- maybe I needed to set the 'Provider string' value. Using this page as a reference (though I'm not configuring IIS), I was able to determine the correct Provider value ("Provider=MSDASQL;DRIVER={Microsoft ODBC for ORACLE};UID=User;PWD=Password;Server=Your_TNSNames_Alias") under item 9.

I recreated the linked server but it still didn't work. I looked in the Registry, and in fact created an ORACLE_HOME string value at HKLM\Software\Oracle. That didn't help either, so I removed that value. (I did notice that setting this value fixed something in Toad 9.7.2 but that story is out of scope for this post.) I even restarted my workstation a couple of times in an effort to appease the Oracle Client God. Nothing worked. My linked server was still broken.

Finally I examined my PATH environment variable. Now, I've struggled mightily with configuring Oracle clients because my company has versions of Oracle ranging from 8i-11. My PATH was collateral damage, and contained references to two Oracle installations. The first reference was to an 11 client's root, and the second was to a 10 client's bin directory. At some point in the past I think that I read that the probing / search for an Oracle client stops when the first client home installation is found. With this in mind, I altered the 11 client path element to point to the bin directory rather than the 11 client root. Restarted the SQL Server 2008 Express service and my linked server was alive and kicking.

So what have I learned after 4 hours of tinkering with SQL Server and Oracle client interaction? Well, there's got to be an easier way. It seems to me that the Oracle client setup and configuration process is opaque. Example: is ORACLE_HOME needed in the registry, as an environment variable, both places, or neither one? The answer seems to be that it depends on the application. I've always been lucky that my installations have worked on a server, but it seems like a fragile process for a volatile developer workstation.

Monday, March 1, 2010

Who gets the money?

Recently I had to decide on merit salary increases. One of the toughest decisions came down to a couple of folks that I'll call Yin and Yang.

Yang is an expert developer, technically brilliant, always has a clever answer to a problem.

Yin is dependable, reliable, always gets the job done. I can always count on Yin to cheerfully accept and complete any task.

But...

Yang's hubris sometimes causes careless mistakes. Yang is also high maintenance, frequently requiring meetings to discuss the most minute of details and risks. Yang requires a surprising amount of micromanagement to ensure that assignments stay on track, and don't veer off into the realm of overarchitecture.

Yin stopped learning new things years ago. Yin gets the job done through brute force.

Ultimately I ruled in favor of Yin. Both developers adequately complete their tasks but take different approaches. Both are important parts of the team. I went with the person who made my life easiest. Though Yang's solutions are technically superior to Yin's, at the end of the day the user doesn't care about elegant code- users just want their applications to work.

Wednesday, January 6, 2010

ASP.NET MVC Action methods called twice

I'm converting an ASP.NET Web Forms application to ASP.NET MVC. The UI is not changing, so I'm copying and pasting chunks of ASPX and ASCX files into my Views, and then replacing the Web Forms-specific code (example: tags with 'asp' prefixes) with HTML and/or calls to the System.Web.Mvc.HtmlHelper class. But this conversion doesn't happen instantaneously - there might be a period of time between the creation of the view and completion of conversion.

I had a breakpoint set in an action method and noticed that the method was being called twice. Once with the parameter that I expected (an int representing a primary key in a database) but then also with the default value specified when the route was registered. The net effect was that the desired View was displayed, but that also a call was made to the previous View. Not good.

I spent time with Fiddler, and I got an idea. I replaced all of the remaining legacy asp tags that I hadn't yet converted, and the problem disappeared. Sure, sooner or later the problem would have resolved itself as the conversion process progressed, but I'm (unfortunately?) not the type of person who can let a mystery like this one remain unsolved.

Wednesday, December 16, 2009

Translating Data With PowerShell

I recently was confronted with a situation where I needed to transform a list of developer-friendly filenames contained in a text file into a user-friendly list of report names. In the past I probably would have written a Console app to do this work but PowerShell is a much more lightweight solution to this problem.

The filenames were the result of a query against TFS version control and were in the format of $/[TFS Project Name]/Reports/[Codeline]/[Visual Studio Project Name]/*.rdl. A given *.rdl file, for example "UpcomingBdayRpt.rdl", would be represented in the application as "Upcoming Birthdays Report". I needed to provide the names which the tester was familiar with in the application. Providing a list of cryptic names like "UpcomingBdayRpt.rdl" would be as useful as providing a list in cuneiform (assuming that the tester doesn't read cuneiform).

The first step was to get the list into PowerShell. (For the purposes of this demonstration assume that I've already navigated in PowerShell to the directory that contains the source files.)
$allReportFiles = Get-Content .\MyInputFile.txt

Because I had a predictable path pattern I could use Split on the forward slash to get a list of only the filename. I removed the extension on the filename with -replace.
$rdlNames = $allReportFiles | ForEach-Object{ $_.split("/")[5] -replace ".rdl", ""}

The database that supports our application has a cross-reference table that relates the *.rdl name to the user-friendly name. I exported the two columns that I needed into a comma-delimited file named "reports.txt". The format of the text file looked like this:
DocumentLetter,Document Letter
InterviewReport,Interview Report
OutstandingItemsLetter,Outstanding Items Letter

I got lazy during the next step. Pipelining the contents of $rdlNames to ForEach-Object, I used GetChildItem to get a reference to my data file, searched that file for a line that contained the filename contained in "$_", and, when the line was found, got the FileName, Pattern, and Line properties. Note that I don't need the FileName property, but included it so that I could confirm that my data was coming from where I expected it. I'm paranoid about things like that.
$data = $rdlNames | ForEach-Object { Get-ChildItem * -include reports* | Select-String -pattern $_.Trim() -SimpleMatch} | Select-Object -property FileName, Pattern, Line -unique
So why do I consider this lazy? Well, there are almost certainly more elegant solutions to this problem. But then again, this is just a trivial script meant to solve a unique problem. The solution doesn't have to stand the test of time nor be incredibly efficient- it just needs to get the job done.

The final step is just to extract the user-friendly names from the objects in $data using $_.Line.split(",")[1]. In case I need to discuss one of the reports with the tester, I provide the developer-friendly filename in brackets so that we can translate between the two names (developer and tester).
$data | ForEach-Object{$_.Line.split(",")[1] + " [" + $_.Pattern + "]" } | Sort-Object

So that's it. I copied and pasted the output from the final line into an email and I was done. The tester had the information that she needed, all was right in the world, and I could leave on time for once.

Thursday, November 19, 2009

Phantom TNSNAMES entries

I have a PowerShell script that uses Oracle.DataAccess. It retrieves its connection information from an existing configuration file on a server. The connection information is as basic as you can get: Data Source, User Id, Password. I had already successfully installed and executed the script on a development server but received the following error when I attempted to run the script on my test server: "ORA-12505: TNS:listener does not currently know of SID given in connect descriptor".

I was baffled. The test server is an application server that has been running in good order for a couple of years. The application that runs on it (let's call it SERVICE) successfully talks to the "missing" database almost continuously. The TNSNAMES file on the test server contains a single entry, and I knew that entry was valid because SERVICE was up and running.

I immediately started checking event logs, experimenting with case sensitivity in the connection string and the PowerShell script, and tweaking environment variables. I executed the relevant steps from the script in the PowerShell console. I scoured the server's file system for extra TNSNAMES.ORA files but found only the one that I expected. I stopped SERVICE in case it was somehow blocking my script's database calls. To make the issue even more confounding, I could specify a Data Source that wasn't even listed in the TNSNAMES file and I could then open the OracleConnection!

After several hours I gave up. I returned to the problem over a week later with a strange notion to check any mapped network drives. I've got a default mapped drive created (I assume) when my domain account was created. Looking in this drive I had a Eureka! moment: an old TNSNAMES file from my development machine that was full of entries. Suddenly it all made sense: I could connect to databases not present in the test server's TNSNAMES file because the entries were present in the 'network' TNSNAMES file. And, conversely, I couldn't connect to the test server's TNS entry because the port value had changed in the past couple of months and my 'network' TNSNAMES file had the old, invalid port.

What I had expected to be a trivial smoke test turned out to be much, much more. There's a lesson in here somewhere. The obvious one is that I probably should have initially started off configuring the script with the credentials with which it will be used in production. Another lesson is that software development can be maddeningly frustrating and that sometimes you just have to walk away. We don't all have the luxury of time that I did during this exercise, but sometimes some distance from a problem really brings clarity.

Friday, October 23, 2009

Visual Studio 2010 Beta1 uninstall

There's a new Visual Studio 2010 beta available. I wanted to see if the problems that I've experienced using TeamFuze with beta 1 were still present in the new bits. I hit what seemed to be a showstopper uninstalling from Windows 7 Professional x64: a prompt for the media installation path so that the 'TFS Object Model' could be removed. Uh-oh, I thought- I had just deleted the installation iso file AND recycled. I thought for a moment that I was either going to have to pull out a file undelete tool or download the beta 1 again.

Luckily, I found Scott Hanselman's post and was able to uninstall beta 1 without resorting to extraordinary measures.