I have a DNN site (05.02.03) in test and nearing release into production and I would like to suppress the details of error messages (i.e. Null Reference Exception, and others) to general users (admins can still see the details). Debug is off in the web.config.
By suppressing, I mean the only error message I want to display to the general user (all users) is something like "An Exception has occured". I don't want the details of that exception to be displayed to the general user. I still want it logged in greater detail in the Event Viewer.
How would I go about doing this?
Update: I have "Use Custom Error Messages" checked. Which shows a error message like:
A critical error has occurred.[vbCrLf] Object reference not set to an instance of an object.
I want just the "A critical error has occured." error message to be displayed to general users.
I don't want the "Object referece not set to an instance of an object." to be displayed to general users
You should have "Use Custom Error Messages" checked in the Host Settings.
If UseCustomErrorMessages is checked, ProcessModuleLoadException will behave almost as you specified. It will log messages to EventLog and will show a friendly error message without exception details. Message header texts are found in SharedResources.resx.
However, DNN custom error messages uses objUserInfo.IsSuperUser to check if the user is a Host account. Users in the Administrators role will behave like a normal users.
A little caveat: I checked these from DNN 4.9.5 sources, you should double-check from yours.
Related
Short Version
Please read at the very bottom for a short version of the question.
Situation
In a question I asked last week, I struggled in finding a solution, which makes our asp.net error visualization waterproof, since there are some edge cases where the asp.net exception handling fails and hence no proper exception visualizations can be created:
How to properly set up ASP.NET web.config to show application specific, safe and user friendly asp.net error messages in edge cases
Desired Solution
As an alternative to the way I described there, in my opinion the best way to make the exception visualization reliable, would be to use the httpErrors-element in system.webServer as a failsave so that any error which is not properly handled by asp.net, leads to a generic error page which is shown based on the settings of the httpErrors-element .
To accomplish this, there must be two things possible:
Error pages properly handled by the application must pass through iis without being replaced with a generic error message
Errors which could not be processed properly in asp.net, must be replaced through IIS.
It is my understanding, that this very behaviour is meant by the existingResponse="Auto" parameter in the httpErrors-element.
The ms documentation states:
Leaves the response untouched only if the SetStatus flag is set.
This is exactly what is necessary: Any successful error page creation in the application (through Application_Error or through an explicitly defined error handling page) can set
Response.TrySkipIisCustomErrors = true and IIS would let the error page pass through. However, every other error which was not successfully handled by the application in asp.net, would not set the flag and hence get the error page which is specified in the httpErrors-element.
The Problem
Sadly, it seems that in MVC5-applications (I don’t known whether the same behavior is true in other environments), the Response.TrySkipIisCustomErrors (fTrySkipCustomErrors) seems to be set automatically to [true], even if it is not set by the application.
Hence we are at the same place, as in my other post: If the error handling of the application blows, there is no way to show an application specific error with existingResponse="Auto", since its not possible to reset the fTrySkipCustomErrors flag.
As an alternative, one can set existingResponse="PassThrough". That's what we do currently, since we want to generate our error pages with a support-code and other helpfull information about the error to be shown to the user, or one can use existingResponse="Replace", but this is not an option, since it replaces any error page so that we don’t can show the user any error-specific information such as the support-code mentionen before.
Quesition in Short
The question is therefore, how to make sure that MVC5 (asp.net) does not set the fTrySkipCustomErrors flag automatically to [true], since there are situations, where no application code is executed and hence the Response.TrySkipIisCustomErrors (fTrySkipCustomErrors) cannot be set to false, what renders the existingResponse="Auto" parameter moot.
To check such a situation where the asp.net MVC5 exception handling blows but the fTrySkipCustomErrors flag is set to true, please request the following page from your MVC5 application:
http[s]://[yourWebsite]/com1
Please note: I'm not interested in disabling the above error. It's an example. I want the error visualization reliable and not to have to circumvent every error that possibly can blow asp.net's error handling mechanisms.
My goal is to influence the error descriptions that appear in BizTalk Administration Console in the Error Information tab of suspended instance windows, after errors occur in my custom functoids. If possible, I would also like the ErrorReport.Description promoted property to display this error description on the failed message.
I've read everything I can find about custom functoid development, but I can't find much about error handling within them. In particular, whenever my functoids throw exceptions, I see the boilerplate "Exception has been thrown at the target of an invocation" message that occurs whenever exceptions occur through reflection, rather than the message on the exception itself.
I had hoped to find something within the BaseFunctoid class framework that would allow me to submit an error string, so as to traverse the reflection boundary. Is there some way to pass error information from within a custom functoid, such that the BizTalk Administration Console will display it?
If I emulate the approach taken by DatabaseLookupFunctoid and DatabaseErrorExtractFunctoid, is there some way I can fail the map with the extracted error, rather than mapping it to a field on the destination schema as is shown in its examples?
The simplest way to do this is using custom C#, writing something like this in your code:
System.Diagnostics.EventLog.WriteEntry("EVENT_LOG_SOURCE", "Error message...", System.Diagnostics.EventLogEntryType.Error);
As Johns-305 mentions, you need to make sure your event source is registered (e.g. System.Diagnostics.EventLog.CreateEventSource("EVENT_LOG_SOURCE", "Application") - but this should really be done as part of your installation steps with an EventLogInstaller or some kind of script to set up the environment). It's certainly true that error handling in BizTalk is just .NET error handling, but one thing to keep in mind is that maps are actually executing as XSLT, and the context in which their executing can have a major impact on how exceptions and errors will be handled, particularly unhandled exceptions.
Orchestrations
If you're executing a transform in an orchestration that has exception handling in it, the exception thrown will be handled and may even fall into additional logging you have in the orchestration - in other words, executing a throw from a C# functiod will work the way you'd think it would work elsewhere in C#. However, I try to avoid this since you never know if a map will at some point be used else where and because exception handling in XSLT doesn't always work the way you'd think (see below).
Send/Receive Ports
Unfortunately, if you're executing a map on a send or receive port and throw an exception within it, you will almost definitely get very unhelpful error message in the event log and a suspended instance in the group hub. There is no easy, straightforward way to simple "cancel" a transform - XSLT 1.0 doesn't have any specified way of doing that (see for example Throwing an exception from XSLT). That leaves you with outputting an error string to a particular node in the output (and/or to the EventLog), or writing lots of completely custom XSLT to try to validate input, or designing your schemas properly and using a validating component where necessary. For example, if you have a node that must match a particular regex, or should never be empty, or should never repeat more than X times, make sure you set those restrictions on the schema and then make sure you pass it through the XmlValidator or similar before attempting to map.
The simplest answer is, you just do.
Keep in mind, there is nothing special at all about error handling in BizTalk apps, it's just regular plain old .Net error handling.
So, what you do is catch the error in you code, write the details to the Windows Event Log (be sure to create a custom Event Source) and...that's it. That is all I do. I don't worry about what appear in BT Admin specifically.strong text
I am using sharepoint 2010 but I am facing
Tail period has expired
http://ceekam.com/blog/?p=519
I had already tried this but it didnt work for me
but now the error changes for me now it becomes Unexpected error has occurred as I change my site collection web config configuration for showing proper error it says object reference not set to an instance of an object
Web.config files are for the entire application, not just for a single site collection.
Typically, when I see an error stating "object reference not set to an instance of an object", it boils down to order of operations within custom code (which could include javascript, etc). If you look at the stack trace, you might discover exactly what the issue is.
I am trying to develop a standard when I code applications.
I was curious as to what other developers did when it comes to sql errors or general program errors. Do you output the error to the screen, write to a log file, or something else?
It really depends on the severity of the error.
Is it a show stopper?
Can the software automatically retry and get away with no message?
Can it be ignored?
You can log every exception, or just certain ones, or none. I have a custom Exception class which logs every exception created (of that type).
I have an unhandled exception handler which emails me when there is one.
I'd only send a message to the user when it will change the way the application works from the user's point of view.
Your question is a bit subjective and you would get opinion-based answers if the entire community bothered to answer.
If the error is relevant and important to the user (e.g.: invalid username/password) display it to the user using a message box.
If the error is relevant to the developer, or can be used in the debugging process, use a log or a console output.
The trick is to identify which and how the errors should be displayed to the user. You don't want to bombard the user with exceptions and complicated errors on which the user has no idea on how to act upon.
Generally, in software design, which of the options below is preferred when there is a problem or error with a resource such as a database or file?
Show an error message
Do not show an error message and act as though the resource was empty (eg. do not populate a GUI component)]
For example, should the user see an empty DataGrid following which they complain, or should there be an error message? Which is better?
I don't see this as an either/or. Also, we need to consider all "users" of the system.
First consider the UI. Let's consider a contrived general case: you are populating a UI by calling a service which in turn uses a couple of of databases (for example a "current data" and an "historic data") database.
There are at least these possibilities:
It all works, data is retrieved
It all works but as it happens there's no data for this particular query
Can't reach the service
Service is invoked, but one database is down
Service is invoked, but both databases are down
Then also consider your application's semantics. Can your applciation procede in a "degraded" mode if all the data cannot be retrieved? For example, we can't query the history but that doesn't stop us creating a new item.,
Now also consider the roles here. There's the person using the UI, there's also support and maintenance people who need to know about and fix problems.
My general rules:
First Failure Data capture: Whichever component first detects an error should log it in some detail. So, service up, database down the service should log the problem. Service down, the UI should log the problem. This log should be a technical record targeting the support roles.
UIs should be tolerant: if at all possible run in a degraded mode. So if the service is down but (for example) local working is possible put up an empty screen and continue. BUT ...
Always indicate a problem: The "no data for this query" and "databases unavailable" cases may both result in an empty screen. The user needs to know the status of the display, is it showing complete information, partial information (eg. because one DB is down) or is no information available (eg. service or both dbs down). So have a "Status" field somewhere on the screen. Giving messages such as
Historica Data not currently available
or
There are problems retrieveing
information, if these persist please
contact support ...
There are some pitfalls to each of the options
Showing error message
This is specially helpful when your application is in testing stage or public testing. Also when clients meets an error, he or she can copy down the details and forward to you.
However sometimes this error message gets very ugly (call stacks and so on - remember ASP.NET?) and it becomes so large that it becomes difficult for clients to copy down the details.
Do not show error message and act as though nothing happened =)
This is useful when you don't want error messages to cog up your software UI design. But be reminded that it becomes difficult and further error prone when clients can't differentiate between an actual error, or really nothing on the GUI. The error stays there and nothing gets fixed.
My stand
Get the best of both worlds. In fact most modern applications how have a very good error handling process. I'll take the example of Mozilla Firefox 3.
A deadly error occurred and Firefox crashes
Error is captured and stored into a file as a form of error report
Error Reporting Application pops up apologizing to the user
Ask the user if the user want to send the error report to the software dev team
Then ask the user if want to restart the application
Or if the error is a warning or of lesser severity:
Show a simple error code and tell the user that there's the error with that action. Something like: "Error 123 at RequestSalary() Line 2"
The practice I usualy use is:
If the error didn't happen due to user error, then you should try to handle the error quietly.
If the error occurred because of some external problem (such as no internet connection) then you should alert the user.
IMO you should show a message (albeit a user friendly one and not something like "java.io.IOException: Connection timed out".) You could have a message box telling the user that an error occured while getting the data and provide helpful tips like: Trying after some time, check network cable, etc.
Also allow user to report that error to you (error reporting build into the app) that will send you the actual error and stack trace.