Is there a REST API method in Camunda to throw boundary error event to a running process instance?
I have searched a lot but can not find.
You cannot throw errors from the outside - they always happen from within the process model (e.g. Service Tasks or Throwing Error Events).
If you want to influence process flow from the outside use a message - there you will find the proper API method in the docs. Consider is as "error message" :-)
Cheers
Bernd
Related
I am new to mulesoft and while studing it i strugle to understand why on module "onErrorPropagate" the error is being rethrown after executing the scope.
can you explain the benefits?
An on-error-propagate will rollback any transactions, execute, and use that result to rethrow the existing error––meaning its owner will be considered as “failing.”
The best use is in a layered system, to allow each layer to do its own small part of an error response.
If you are familiar with Java you can think of it as catching the exception and re-throwing it. For example, sometimes you want to do something with the error yourself, but still want to propagate it upwards for higher levels to deal with.
You could add logging in a specific flow for the error but then leave it to the parent flows to actually deal with the exception.
The "onErrorPropagate" propagates (rethrows) the error to the parent flow (or the global error handler if it's already reached the main flow).
This can be usefull in a few cases.
Say you have some flow specific error handling (e.g. if something goes wrong, set a default payload).
Then you propagate this error to the next level where you have your Global error handler that, say, stores some info in a QA database.
You don't want to have that database connector in every single error handler.
In this way you can achieve a 'java inherritance' like structure, for your errors.
Side note: if you want your error to only be handled and do nothing further, you can use "onErrorContinue"
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
Using APIKit in Mule, I need to return a 404 status code if a particular resource is not found when executing my flow.
I can see three ways of handling this:
Throw a custom business exception(using a groovy script) i.e
PersonNotFoundException and use the
apikit:mapping-exception-strategy to map that exception to '404'
Throw the existing Mule exception
org.mule.module.apikit.exception.NotFoundException which is already
mapped to '404'
Do no throw an exception and manually set the http response and
status code within the normal flow of my message.
What's the best practice here? Use exceptions for flow control? and if so use the Mule exception or a custom business exception?
I think this is one of those weird combinations between API best practices and Mule best practices.
For generic resources, ie "/users" I would use the Mule Not Found Exception (404), but for an item resource that does not exist, ie "/users/jim-smith" for usability purposes I would throw a custom exception with "The user requested does not exist" or "You do not have permission to access this user" (status 401) whichever the case may be to best help developers utilizing your API.
I think the biggest advantage to the exception strategy instead of just manually changing the responses yourself is it creates a clear flow where you can easily determine what is a successful response, and what is a failed response.
That and using an exception handler within Mule you can return back a uniform error response to the user (in JSON, XML, etc).
But others might disagree with me, and just manually setting the status code and response yourself does offer the most flexibility, but also allows for inconsistencies.
Short and simple:
How to catch pgPL/SQL exceptions with QtSQL?
I haven't found any example or info at the docs.
More details:
I'm developing the front end for a system with Qt 5.3. The database perform some validation at some of the inputs and raise custom exceptions when something is invalid. What I want is to be able to handle these exceptions at he front end code, showing appropriate messages to the user.
EDIT:
I have tried to use the QSqlError class. Although it gave me the exception, it gave me too much data which will need to be parsed to be useful. Is there a way to get the exception raised without parsing the messages?
So on the server I send back custom exception messages, meant to be displayed to the user (think "Bad Username/Password", "Account has been locked out" etc.)
However, when I view the Exception message in silverlight it is prefixed with "Load operation failed for x." I was thinking that Exception.InnerException would be a good place to put the original Exception, but I guess the RIA team didn't agree.
Is there a way to get my original exception message? Sure, I could write a quick regex to parse it out, but that feels dirty... Is that my only option?
I read about a solution that may work for you. I have yet to implement it myself though.
http://mark.mymonster.nl/2011/02/10/make-use-of-wcf-faultcontracts-in-silverlight-clients/