SteveOH

Last night I ran into an idiotic error while deploying an application update into our production environment.  Here’s the full error:

System.Web.HttpParseException (0×80004005): Cannot create an object of type ‘System.Type’ from its string representation ‘System.Int64′ for the ‘DataType’ property. —> System.Web.HttpParseException (0×80004005): Cannot create an object of type ‘System.Type’ from its string representation ‘System.Int64′ for the ‘DataType’ property. —> System.Web.HttpException (0×80004005): Cannot create an object of type ‘System.Type’ from its string representation ‘System.Int64′ for the ‘DataType’ property. at System.Web.UI.PropertyConverter.ObjectFromString(Type objType, MemberInfo propertyInfo, String value) at System.Web.UI.ControlBuilder.AddProperty(String filter, String name, String value, Boolean mainDirectiveMode) at System.Web.UI.ControlBuilder.PreprocessAttributes(ParsedAttributeCollection attribs) at System.Web.UI.ControlBuilder.Init(TemplateParser parser, ControlBuilder parentBuilder, Type type, String tagName, String id, IDictionary attribs) at System.Web.UI.ControlBuilder.CreateBuilderFromType(TemplateParser parser, ControlBuilder parentBuilder, Type type, String tagName, String id, IDictionary attribs, Int32 line, String sourceFileName) at System.Web.UI.ControlBuilder.CreateChildBuilder(String filter, String tagName, IDictionary attribs, TemplateParser parser, ControlBuilder parentBuilder, String id, Int32 line, VirtualPath virtualPath, Type& childType, Boolean defaultProperty) at System.Web.UI.TemplateParser.ProcessBeginTag(Match match, String inputText) at System.Web.UI.TemplateParser.ParseStringInternal(String text, Encoding fileEncoding) at System.Web.UI.TemplateParser.ProcessException(Exception ex) at System.Web.UI.TemplateParser.ParseStringInternal(String text, Encoding fileEncoding) at System.Web.UI.TemplateParser.ParseString(String text, VirtualPath virtualPath, Encoding fileEncoding) at System.Web.UI.TemplateParser.ParseString(String text, VirtualPath virtualPath, Encoding fileEncoding) at System.Web.UI.TemplateParser.ParseFile(String physicalPath, VirtualPath virtualPath) at System.Web.UI.TemplateParser.Parse() at System.Web.Compilation.BaseTemplateBuildProvider.get_CodeCompilerType() at System.Web.Compilation.BuildProvider.GetCompilerTypeFromBuildProvider(BuildProvider buildProvider) at System.Web.Compilation.BuildProvidersCompiler.ProcessBuildProviders() at System.Web.Compilation.BuildProvidersCompiler.PerformBuild() at System.Web.Compilation.BuildManager.CompileWebFile(VirtualPath virtualPath) at System.Web.Compilation.BuildManager.GetVPathBuildResultInternal(VirtualPath virtualPath, Boolean noBuild, Boolean allowCrossApp, Boolean allowBuildInPrecompile, Boolean throwIfNotFound, Boolean ensureIsUpToDate) at System.Web.Compilation.BuildManager.GetVPathBuildResultWithNoAssert(HttpContext context, VirtualPath virtualPath, Boolean noBuild, Boolean allowCrossApp, Boolean allowBuildInPrecompile, Boolean throwIfNotFound, Boolean ensureIsUpToDate) at System.Web.Compilation.BuildManager.GetVirtualPathObjectFactory(VirtualPath virtualPath, HttpContext context, Boolean allowCrossApp, Boolean throwIfNotFound) at System.Web.Compilation.BuildManager.CreateInstanceFromVirtualPath(VirtualPath virtualPath, Type requiredBaseType, HttpContext context, Boolean allowCrossApp) at System.Web.UI.PageHandlerFactory.GetHandlerHelper(HttpContext context, String requestType, VirtualPath virtualPath, String physicalPath) at System.Web.HttpApplication.MaterializeHandlerExecutionStep.System.Web.HttpApplication.IExecutionStep.Execute() at System.Web.HttpApplication.ExecuteStep(IExecutionStep step, Boolean& completedSynchronously)

This page was working perfectly on 2 development environments and 1 staging environment, and they all had the same version of the controls installed (BIN installed).  But when deployed to the production server, the page errors out with this stupid error.

Telerik’s explanation is that the telerik.web.ui.dll and the telerik.web.design.dll have different versions, but this was not the case as I verified versions were correct, rolled back to the previous DLLs prior to the deployment, etc.  I cleared the .NET temporary file cache, restarted IIS, restarted the web service, re-referenced the controls in the web.config, even tried updating the GAC.  Nothing worked.

I followed Telerik’s instructions (different than above) as well, to no avail.

Since I was working against a deadline for this deploy, my only solution was to remove the RadNumericTextBox and replace it with a RadTextBox and deal with the validation of the input on the server-side.

Great solution?  No.  A solution at all?  Definitely not.  But I wasn’t about to wait to hear back from Telerik with their generic responses and then start shooting in the dark all over again.

 

I will be doing this configuration on my test machine very soon since my previous guide (here) is a bit outdated.  For now you can follow the previous instructions and modify them per the instructions below:

From SuperUser:

I’ve done it but not exactly like in your link, because of some kind of problem (bug?) in Grub2 (tutorial is with grub “1″ but I’ve Grub2), specifically in this

title Windows Vista/Longhorn
rootnoverify (hd0,0) makeactive
chainloader (hd0,1)/truecrypt.mbr
boot

The problem is known and posted on many forums.

My solution was:

1. Encrypt Windows7 system partition using truecrypt, selecting Single boot and overwriting Grub2 loader with truecrypt loader
2. Boot Debian from Rescue CD and install grub2 bootloader NOT on MBR but on /dev/sda3 which is Debian / partition (so truecrypt loader was not overrided)

Now while booting truecrypt bootmenu is shown and if I’d access Win7 I’m entering password, but if I’d enter debian (via Grub2) I hit esc key and then truecrypt loader is searching all other partitions for boot loader and finding Grub2 which resides on /dev/sda3 and load system properly.

I think its the best way to do this for now (until sb find resolution for Grub2 to read /boot/truecrypt.mbr without errors).

February 22, 2010

 

Robert L. Glass

 

This month’s column is simply a collection of what I consider to be facts—truths, if you will—about software engineering. I’m presenting this software engineering laundry list because far too many people who call themselves software engineers, or computer scientists, or programmers, or whatever nom du jour you prefer, either aren’t familiar with these facts or have forgotten them.

I don’t expect you to agree with all these facts; some of them might even upset you. Great! Then we can begin a dialog about which facts really are facts and which are merely figments of my vivid loyal opposition imagination! Enough preliminaries. Here are the most frequently forgotten fundamental facts about software engineering. Some are of vital importance—we forget them at considerable risk.

 

Complexity

C1. For every 10-percent increase in problem complexity, there is a 100-percent increase in the software solution�s complexity. That’s not a condition to try to change (even though reducing complexity is always desirable); that’s just the way it is. (For one explanation of why this is so, see RD2 in the section “Requirements and design.”)

 

People

P1. The most important factor in attacking complexity is not the tools and techniques that programmers use but rather the quality of the programmers themselves.

P2. Good programmers are up to 30 times better than mediocre programmers, according to “individual differences” research. Given that their pay is never commensurate, they are the biggest bargains in the software field.

 

Tools and techniques

T1. Most software tool and technique improvements account for about a 5- to 30-percent increase in productivity and quality. But at one time or another, most of these improvements have been claimed by someone to have “order of magnitude” (factor of 10) benefits. Hype is the plague on the house of software.

T2. Learning a new tool or technique actually lowers programmer productivity and product quality initially. You achieve the eventual benefit only after overcoming this learning curve.

T3. Therefore, adopting new tools and techniques is worthwhile, but only if you (a) realistically view their value and (b) use patience in measuring their benefits.

 

Quality

Q1. Quality is a collection of attributes. Various people define those attributes differently, but a commonly accepted collection is portability, reliability, efficiency, human engineering, testability, understandability, and modifiability.

Q2. Quality is not the same as satisfying users, meeting requirements, or meeting cost and schedule targets. However, all these things have an interesting relationship: User satisfaction = quality product + meets requirements + delivered when needed + appropriate cost.

Q3. Because quality is not simply reliability, it is about much more than software defects.

Q4. Trying to improve one quality attribute often degrades another. For example, attempts to improve efficiency often degrade modifiability.

 

Reliability

RE1. Error detection and removal accounts for roughly 40 percent of development costs. Thus it is the most important phase of the development life cycle.

RE2. There are certain kinds of software errors that most programmers make frequently. These include off-by-one indexing, definition or reference inconsistency, and omitting deep design details. That is why, for example, N-version programming, which attempts to create multiple diverse solutions through multiple programmers, can never completely achieve its promise.

RE3. Software that a typical programmer believes to be thoroughly tested has often had only about 55 to 60 percent of its logic paths executed. Automated support, such as coverage analyzers, can raise that to roughly 85 to 90 percent. Testing at the 100-percent level is nearly impossible.

RE4. Even if 100-percent test coverage (see RE3) were possible, that criteria would be insufficient for testing. Roughly 35 percent of software defects emerge from missing logic paths, and another 40 percent are from the execution of a unique combination of logic paths. They will not be caught by 100-percent coverage (100-percent coverage can, therefore, potentially detect only about 25 percent of the errors!).

RE5. There is no single best approach to software error removal. A combination of several approaches, such as inspections and several kinds of testing and fault tolerance, is necessary.

RE6. (corollary to RE5) Software will always contain residual defects, after even the most rigorous error removal. The goal is to minimize the number and especially the severity of those defects.

 

Efficiency

EF1. Efficiency is more often a matter of good design than of good coding. So, if a project requires efficiency, efficiency must be considered early in the life cycle.

EF2. High-order language (HOL) code, with appropriate compiler optimizations, can be made about 90 percent as efficient as the comparable assembler code. But that statement is highly task dependent; some tasks are much harder than others to code efficiently in HOL.

EF3. There are trade-offs between size and time optimization. Often, improving one degrades the other.

 

Maintenance

M1. Quality and maintenance have an interesting relationship (see Q3 and Q4).

M2. Maintenance typically consumes about 40 to 80 percent (60 percent average) of software costs. Therefore, it is probably the most important life cycle phase.

M3. Enhancement is responsible for roughly 60 percent of software maintenance costs. Error correction is roughly 17 percent. So, software maintenance is largely about adding new capability to old software, not about fixing it.

M4. The previous two facts constitute what you could call the “60/60″ rule of software.

M5. Most software development tasks and software maintenance tasks are the same—except for the additional maintenance task of “understanding the existing product.” This task is the dominant maintenance activity, consuming roughly 30 percent of maintenance time. So, you could claim that maintenance is more difficult than development.

 

Requirements and design

RD1. One of the two most common causes of runaway projects is unstable requirements. (For the other, see ES1.)

RD2. When a project moves from requirements to design, the solution process’s complexity causes an explosion of “derived requirements.” The list of requirements for the design phase is often 50 times longer than the list of original requirements.

RD3. This requirements explosion is partly why it is difficult to implement requirements traceability (tracing the original requirements through the artifacts of the succeeding lifecycle phases), even though everyone agrees this is desirable.

RD4. A software problem seldom has one best design solution. (Bill Curtis has said that in a room full of expert software designers, if any two agree, that’s a majority!) That’s why, for example, trying to provide reusable design solutions has so long resisted significant progress.

 

Reviews and inspections

RI1. Rigorous reviews commonly remove up to 90 percent of errors from a software product before the first test case is run. (Many research findings support this; of course, it’s extremely difficult to know when you’ve found 100 percent of a software product’s errors!)

RI2. Rigorous reviews are more effective, and more cost effective, than any other error-removal strategy, including testing. But they cannot and should not replace testing (see RE5).

RI3. Rigorous reviews are extremely challenging to do well, and most organizations do not do them, at least not for 100 percent of their software artifacts.

RI4. Post-delivery reviews are generally acknowledged to be important, both for determining customer satisfaction and for process improvement, but most organizations do not perform them. By the time such reviews should be held (three to 12 months after delivery), potential review participants have generally scattered to other projects.

 

Reuse

REU1. Reuse-in-the-small (libraries of subroutines) began nearly 50 years ago and is a well-solved problem.

REU2. Reuse-in-the-large (components) remains largely unsolved, even though everyone agrees it is important and desirable.

REU3. Disagreement exists about why reuse-in-the-large is unsolved, although most agree that it is a management, not technology, problem (will, not skill). (Others say that finding sufficiently common subproblems across programming tasks is difficult. This would make reuse-in-the-large a problem inherent in the nature of software and the problems it solves, and thus relatively unsolvable).

REU4. Reuse-in-the-large works best in families of related systems, and thus is domain dependent. This narrows its potential applicability.

REU5. Pattern reuse is one solution to the problems inherent in code reuse.

 

Estimation

ES1. One of the two most common causes of runaway projects is optimistic estimation. (For the other, see RD1.)

ES2. Most software estimates are performed at the beginning of the life cycle. This makes sense until we realize that this occurs before the requirements phase and thus before the problem is understood. Estimation therefore usually occurs at the wrong time.

ES3. Most software estimates are made, according to several researchers, by either upper management or marketing, not by the people who will build the software or by their managers. Therefore, the wrong people are doing estimation.

ES4. Software estimates are rarely adjusted as the project proceeds. So, those estimates done at the wrong time by the wrong people are usually not corrected.

ES5. Because estimates are so faulty, there is little reason to be concerned when software projects do not meet cost or schedule targets. But everyone is concerned anyway!

ES6. In one study of a project that failed to meet its estimates, the management saw the project as a failure, but the technical participants saw it as the most successful project they had ever worked on! This illustrates the disconnect regarding the role of estimation, and project success, between management and technologists. Given the previous facts, that is hardly surprising.

ES7. Pressure to achieve estimation targets is common and tends to cause programmers to skip good software process. This constitutes an absurd result done for an absurd reason.

 

Research

RES1. Many software researchers advocate rather than investigate. As a result, (a) some advocated concepts are worth less than their advocates believe and (b) there is a shortage of evaluative research to help determine the actual value of new tools and techniques.

There, that’s my two cents’ worth of software engineering fundamental facts. What are yours? I expect, if we can get a dialog going here, that there are a lot of similar facts that I have forgotten—or am not aware of. I’m especially eager to hear what additional facts you can contribute.

And, of course, I realize that some will disagree (perhaps even violently!) with some of the facts I’ve presented. I want to hear about that as well.

Robert L. Glass is the editor of Elsevier’s Journal of Systems and Software and the publisher and editor of The Software Practitioner newsletter. Contact him at rglass@indiana (dot) education; he’d be pleased to hear from you.

Reprinted from IEEE Software, vol. 18, no. 3, 2001, pp. 112, 110–111.

I recently came across this error within an Server 2008 Active Directory Environment where I attempted to add a domain user account to Microsoft SQL Server 2008 x64.

As you may see on the internet, the problem is in fact related to SID, but in my situation it was not the SSID of the user, but of the actual server.  The instance of Server 2008 x64 is running in VMWare Workstation 7 and was created by cloning another VM.  This, of course, makes them identical, such that changing the computer name only results in what ‘appears’ to be disparite systems.  In a workgroup this shouldn’t be an issue, but once Active Directory is introduced, it gets wacky.  AD relies on SID’s, and thus, acts unpredictably when 2 machines / users / groups have the same SID.  This is further exagerated when SQL Server is involved, since it creates and / or stores its own SID for the user.

Here are the steps I followed to solve this issue:

1. Remove the server running SQL Server from the domain.  Reboot.
2. Verify the AD Computer Account has been deleted for the system (on a domain controller).
3. Run newSID.exe (found here) and change the SID of the server running SQL Server to a new random SID.  Reboot.
4. Add server back to the domain and verify the account is created within AD.

Once I did all that, the user added with ease.

Good luck.

1. Use Notepad to open the Web application Web.config file. By default, this file is in the following folder:

2. Add the following section at the end of the web.config file in the respective site:

  <system.webServer>
 <security>
  <requestFiltering>
   <requestLimits maxAllowedContentLength=”1073741824“/>
  </requestFiltering>
 </security>
</system.webServer>

Where the number is in bytes.  This amount would allow you to upload 1024 MB (1 GB) and was calculated as follows (1024 B / KB * 1024 KB / MB * 1024 MB / GB).

Note This code sets the value of the maxAllowedContentLength property to 52428800. Therefore, the maximum file size of an uploaded file is 52428800 bytes. However, set the value of this property so that it is larger than the file that you are trying to upload. Also, set the value of this property so that it is larger than the maximum file upload size that you have configured in SharePoint. If you do not, users will not receive an error message that they are exceeding the size limit if they try to upload a file that is larger than the maximum file upload size that you have configured in SharePoint.

Introduction

When the domain in the URL of your RoundCube instance and the domain the page is actually being rendered from are different are different, you will recieve an odd error message – your browser does not support cookies – from RoundCube.  My set up has an iFrame from one Domain redirecting to another, where RoundCube sits.  Why did I do that? Because the actual domain is ugly and my client requested the web login to their email be the same as the actual domain their emails come from.

FireFox and Chrome allow the login to work fine, but not IE.

However, Internet Explorer does not allow cookies from a 3rd party domain (the second one in the iFrame) to be downloaded, and silently deletes them – security measure I suppose – it is widely documented.  The only way to get around this is to modify the headers sent to notify the browser that the mismatch is intended.

Problem

Email Domain: emailDomain.com
Web Server Domain: webDomain.com
RoundCube URL: webDomain.com/webmail
IMAP Server: mail.emailDomain.com
Redirects: emailDomain.com redirects HTTP traffic to webDomain.com, emailDomain.com redirects SMTP traffic to webDomain.com

NOTES: emailDomain.com is basically just an alias. 

If you try to login through webDomain.com via RoundCube (actually type in webDomain.com/webmail) it will work, the cookies will match up and everyone will be happy.

If you try to login through emailDomain.com (which will open up webDomina.com/webmail in an iFrame) it will not work with Internet Explorer 7 or 8.

Solution

I added the following line of code to the first line of code (after the comments) within the index.php file.

file: /var/www/webmail/index.php (please note that webmail is where RoundCube is installed)

header(‘P3P:CP=”IDC DSP COR ADM DEVi TAIi PSA PSD IVAi IVDi CONi HIS OUR IND CNT”‘);

I recently installed a new hard drive into my server running Server 2008.  Everything worked fine, until I rebooted.  I tried to copy a file to the disk and recieved an error that the drive, in my case E:, was write protected.  I don’t know how or why that happened, but the solution is fairly simple.  The steps are as follows:

1. Open a command prompt (ie. Start > Run > cmd) with administrative privledges
2. Type in the command: diskpart
3. Run the command: list disk
4. Look for the disk number that’s having the problem.  In my case I have a system drive, a RAID 5 configuration (1 logical drive) and then the new drive, so it was DISK 2.  I will continue to use it in the example but note that yours may differ.
5. Select the disk using the following command: sel disk 2
6. Enter the following command: ATTRIBUTES DISK CLEAR READONLY
7. Exit diskpart with the command: exit

Then test by copying a file or folder to the drive.  It should be fairly instantaneous, but worst case you may have to reboot (I did not, however).

That’s about it.  It would be interesting to know WHY this happened, but then again, does it really matter?

Good luck.

I’ve been dealing with this error for the past 2 weeks, trying to authenticate to my IMAP Mail Server (dovecot) over SSL (SASL). I continuously received errors for IMAP authentication. AtMailOpen did not work (and I cannot get it to authenticate correctly). So I tried RoundCube, which looks like a good mesh of functionality and aesthetics.

RoundCube installed great – easy and straight forward. Here is the error I received:

IMAP Error: Authentication for steveoh@thelambdas.com failed (LOGIN): “a001 NO Authentication failed.”

Warning: Cannot modify header information – headers already sent in /var/www/webmail/program/include/rcmail.php on line 951

There is very little to no solutions out there.  So I had to play with the configuration file and each argument, one by one (file: main.inc.php in the config directory).

Leave the username_domain field blank.  My server, apparently, doesn’t require the full email address, only the user name, for authentication.

From:
$rcmail_config['username_domain'] = ‘example.com’;

To:
$rcmail_config['username_domain'] = ”;

This solved the problem, and I’m able to log in using ONLY the user name (ie. username, not username@example.com).

Good luck.

If the boot loader to your Windows Server 2008 machine gets corrupted or deleted for whatever reason, it really is a painstaking process to get it fixed.  The boot loader to my machine got deleted somehow while I was resizing partitions.  After scouring the web, I could not find anything on rebuilding the boot loader for Windows Server 2008.  All I could find were instructions to restore a Windows Vista boot loader, but luckily, the process for Server 2008 is similar.

If you are getting a “bootmgr is missing” error upon startup or something similar, repairing the boot loader will probably fix the problem.

Due to the lack of recovery tools on the Server 2008 installation CD, the boot loader must be rebuilt manually.

For this guide, I’m going to assume your installation has a drive letter of C:.

Insert the Server 2008 installation CD into your DVD-ROM.  Restart your computer and boot from the CD.

Choose to repair your computer, then open the command prompt.

At the command prompt, use the following commands:

c:
cd boot
bootsect /nt60 c: /force /mbr
bootrec /rebuildbcd

After using the “bootrec /rebuldbcd” command, you will be prompted to accept a Windows installation.  Accept the installation, then wait for the process to finish.  Once it’s done, reboot your comptuer and you should have a boot loader ready to go.