The application has an implementation of IEventProcessor. When an unhandled exception is thrown from the ProcessEventsAsync method the EventProcessorHost never re-sends those messages to the running instance of IEventProcessor. (It will re-send if the hosting application is stopped and restarted or if the lease is lost and re-obtained.)
when an exception occurs in processEventAsync the checkpoint will not be set only if it's successful the checkpoint is set using this context.CheckpointAsync()
Checkout the ProcessorErrorAsync method. According the doc, it will be called in the event of an error. You'll have access to the context where can log the id and error.
Related
I have a Django+Apache server, and there is a view with infinite streaming response
def my_view(request):
try:
return StreamingHttpResponse(map(
lambda x: f"{dumps(x)}\n",
data_stream(...) # yields dicts forever every couple of seconds
))
except Exception as e:
print_exc()
return HttpResponse(dumps({
"success": False,
"reason": ERROR_WITH_CLASSNAME.format(e.__class__.__name__)
}), status=500, content_type="application/json")
When client closes the connection to the server, there is no cleanup to be done. data_stream will yield one more message which won't get delivered. No harm done if that message is yielded and not received as there are no side-effects. Overhead from processing that extra message is negligible on our end.
However, after that last message fails to deliver, apache logs 500 response code (100% of requests). It's not getting caught by except block, because print_exc doesn't get called (no entries in error log), so I'm guessing this is apache failing to deliver the response from django and switching to 500 itself.
These 500 errors are triggering false positive alerts in our monitoring system and it's difficult to differentiate an error due to connection exit vs an error in the data_stream logic.
Can I override this behavior to log a different status code in the case of a client disconnect?
From what I understand about the StreamingHttpResponse function is that any exceptions raised inside it are not propagated further. This has to do with how WSGI server works. If you start handling an exception and steal the control, the server will not be able to to finish the HTTP response. So the error is handled by the server and printed in the terminal. If you attach the debugger to this and see how the exception is handled you will be able to find a line in wsgiref/handlers.py where your exception is absorbed and taken care of.
I think in this file- https://github.com/python/cpython/blob/main/Lib/wsgiref/handlers.py
I created a custom workflow in SharePoint and tested it and it worked great. Now when I add documents to the library that the workflow is attached to the status shows the workflow as being suspended. How can I fix this? Error message below.
RequestorId: 8af66be1-83bc-c13e-0000-000000000000. Details: An unhandled exception occurred during the execution of the workflow instance. Exception details: System.ApplicationException: HTTP 500 We're sorry, we weren't able to complete the operation, please try again in a few minutes. If you see this message repeatedly, contact your administrator. {"SPRequestGuid":["8af66be1-83bc-c13e-90bf-29cbfd70fe2b"],"request-id":["8af66be1-83bc-c13e-90bf-29cbfd70fe2b"],"X-FRAME-OPTIONS":["SAMEORIGIN"],"SPRequestDuration":["448"],"SPIisLatency":["0"],"MicrosoftSharePointTeamServices":["15.0.0.4420"],"X-Content-Type-Options":["nosniff"],"X-MS-InvokeApp":["1; RequireReadOnly"],"Date":["Fri, 30 May 2014 19:43:09 GMT"],"Server":["Microsoft-IIS\/8.0"],"X-Powered-By":["ASP.NET"]} at Microsoft.Activities.Hosting.Runtime.Subroutine.SubroutineChild.Execute(CodeActivityContext context) at System.Activities.CodeActivity.InternalExecute(ActivityInstance instance, ActivityExecutor executor, BookmarkManager bookmarkManager) at System.Activities.Runtime.ActivityExecutor.ExecuteActivityWorkItem.ExecuteBody(ActivityExecutor executor, BookmarkManager bookmarkManager, Location resultLocation)
Was resolved, tasks were not started and fell past due date. This caused the workflow to suspend itself. Terminated the workflow action, and that cleared it up immediately.
I am developing application and facing a problem when I use web services.
At any page which request web service, if app goes to background (by search or menu press for example) before request complete it causes an error when I retrieve the application from background again:
An error (Exception of type 'System.Net.WebException' was thrown.) occurred while transmitting data over the HTTP channel.
Any solution for this problem ?
When your application is sent to background, it is suspended, and all connections are therefore cut off. There's nothing you can do about that. Just catch the error and retry the call to the webservice.
You need to call the webservice again when the application is reactivated. One way of doing it is to maintain a bool variable flag.
set it to true when the webservice is started.
set it back to false when the response is received
in the Application_Activated event handler(App.xaml.cs) check the status of flag and call the webservice again if the flag is true.
Otherwise if you just wish to keep your webservice running under lock screen then set
PhoneApplicationService.Current.UserIdleDetectionMode = IdleDetectionMode.Disabled;
If your app goes to background your webrequest wont complete, You cant do anything about that. But you can prevent crash.
When you know the app is going background ( may be in onNavigatedFrom()) you detach the handler you previously attached to xxCompleted event or handle the thrown exception in handler for xxCompleted in the same way. The first solution implies you service client object must be a class member (private maybe), otherwise it wont be in scope in onNavigatedFrom(). To complete the request later you may use a marker ( bool successful, required) and in OnNavigatedTo() you can do like:
if(required && !successful)
{
// make the request again
}
still exception will be caught in the generated reference file, but the app wont crash and you'd know when you need to make the webrequest again.
I found the same problem, when I tried to fetch a sas uri and calling the PhotoChooserTask.show() simultaniously. So I had to ensure that webrequest is complete before the calling PhotoChooserTask.show().
Since we have updated from camunda engine 7.0.0-alpha4 to 7.0.0-Final, we are facing a problem when rolling back transactions that contain either deployment or delete deployment commands. The engine defines listeners DeploymentFailListener and DeleteDeploymentFailListener that are called upon transaction rollback, but at the time of rollback, we are outside camunda's context (i.e. Context has been emptied, and Context.getProcessEngineConfiguration().getRegisteredDeployments() throws a Nullpointer exception).
Is this a bug in the camunda engine? Can we do anything to avoid it?
I've got a Web Service Task in my Control Flow.
The actual Web Service type is void. For testing purposes, the Web Service just throws a new Exception, with a message.
I've got the task outputting to a variable User::ServiceResponse
The Failure path goes to a Send Mail Task, which uses the variable User::ServiceResponse... however, the email received does not contain any text.
When the package executes, the Immediate Window does show a long error, which in part contains my exception message. "Adams Error Message" towards the very end.
SSIS package "....\WebProfile.dtsx" starting.
Error: 0xC002F304 at SVC, Web Service Task: An error occurred with the following error message:
"Microsoft.SqlServer.Dts.Tasks.WebServiceTask.WebserviceTaskException:
The Web Service threw an error during method execution.
The error is: System.Web.Services.Protocols.SoapException:
Server was unable to process request. --->
System.Exception: Adams Error Message
--- End of inner exception stack trace ---.
Without writing a lot of custom script... how can I get the exceptions from my Web Service Task into the Send Mail Task?