Inbox Pattern not working as expected #9756

18 Answer(s)

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  0

  AI-Bot created one month ago

  Support Team ABP Agent

  To ensure the Inbox pattern works reliably in your ABP microservice architecture, consider the following:

  • The ABP Inbox pattern is designed to mark events as processed only after successful handling. If the Processed flag is set to true even when exceptions occur, this typically indicates that the event handler's transaction scope or error handling is not correctly configured.
  • When using multiple DbContexts (SQL Server for AbpEventInbox and MongoDB for other data), you must ensure that the event processing and the update of the Processed flag are part of the same transaction in the SQL Server context. If you perform operations in MongoDB and an exception occurs there, but the SQL Server transaction is already committed, the event may be marked as processed prematurely.
  • Overriding the InboxProcessor and manually calling MarkAsProcessedAsync is not recommended unless you fully control the transaction boundaries and error propagation.

  Recommendations:

  1. Ensure that your event handler logic is wrapped in a transaction that includes both the SQL Server and MongoDB operations (if possible). If not, handle failures in MongoDB by throwing exceptions before the SQL Server transaction commits.

  2. The ABP Inbox processor should only mark events as processed after the handler completes without exceptions. If you see the Processed flag set without handler invocation, check for:

     • Multiple processors or background jobs running in parallel.
     • Manual or custom code that might be updating the Processed flag.
     • Issues with transaction isolation or context misconfiguration.

  3. Review your configuration to ensure the Inbox is set up on the correct DbContext and that only one processor is polling the inbox table.

  4. For reliable retry logic, do not catch and suppress exceptions in your event handler. Let them bubble up so the ABP infrastructure can retry the event.

  Example Configuration:

  Configure<AbpDistributedEventBusOptions>(options =>
  {
      options.Inboxes.Configure(config =>
      {
          config.UseDbContext<YourSqlServerDbContext>();
          // Optionally, set polling interval, batch size, etc.
      });
  });
  

  References:

  • Outbox/Inbox for transactional events
  • Microservice Solution: Distributed Events

  If you follow these guidelines and ensure that exceptions are not suppressed, the ABP Inbox pattern will only mark events as processed after successful handling, and failed events will be retried as expected.

  ---

  This response was generated by AI. If it didn’t solve your problem, feel free to post a new answer — our support team will jump in to help you soon.

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• 

  0

  neethucp created one month ago

  We tried adding a try catch here and set the MarkAsProcessed only if there is no exception.

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• 

  0

  maliming created one month ago

  Support Team Fullstack Developer

  hi

  The problem is that the Processed flag is being set to true even when an exception is thrown during event handling. This results in the event being marked as processed, despite not being successfully handled.

  Can you share your event handler code?

  Thanks

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• 

  0

  neethucp created one month ago

  Hi,

  Please find below the event handler code. _repository stores data to SQL Server Db. _eventHistoryRepository stores data to mongo db.

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• 

  0

  maliming created one month ago

  Support Team Fullstack Developer

  hi

  Which line will throw the exception?

  Thanks.

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• 

  0

  neethucp created one month ago

  Hi, We have events coming from different microservices. So, if the events are not received in the correct order, it throws foreign key exception when inserting to db. await _repository.InsertAsync(appLicence);

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• 

  0

  maliming created one month ago

  Support Team Fullstack Developer

  hi

  Can you try to save the current unit of work?

  await _repository.InsertAsync(appLicence, true);
  

  or

  //Inject _unitOfWorkManager
  await _unitOfWorkManager.Current.SaveChangesAsync();
  

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• 

  0

  maliming created one month ago

  Support Team Fullstack Developer

  hi

  1, 2, 3 in the same UOW. The UOW will rollback if there is an exception. That's MarkAsProcessedAsync will not save in the database.

  

  it throws foreign key exception when inserting to db. await _repository.InsertAsync(appLicence);

  Can you share full logs?

  liming.ma@volosoft.com

  Thanks.

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• 

  0

  maliming created one month ago

  Support Team Fullstack Developer

  hi

  I checked the logs.

  The await uow.CompleteAsync(StoppingToken); throw the exception.

  And await Inbox.MarkAsProcessedAsync(waitingEvent.Id); will rollback because the transaction has failed.

  Can you set LogLevel to Debug to see more EF Core logs?

  .MinimumLevel.Override("Microsoft.EntityFrameworkCore", LogEventLevel.Debug)

  Thanks.

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• 

  0

  neethucp created one month ago

  Hi, I have sent you the debug logs. Can you please check?

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• 

  0

  maliming created one month ago

  Support Team Fullstack Developer

  hi

  I can see the transactions have been rolled back

  Rolled back to transaction savepoint

  This Update SQL statement will not write to your database.

  

  Can you reproduce this issue in the template project? That way, I can debug it locally.

  Thanks

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• 

  0

  maliming created one month ago

  Support Team Fullstack Developer

  hi

  I tested your project. Unable to reproduce the problem.

  Video: https://streamable.com/dhgxj4 raw video https://we.tl/t-ILKnADn1vY

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  0

  neethucp created one month ago

  Hi,

  Processed is getting set to true for us every time, it is not even invoking the handler. https://streamable.com/4wmglj

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• 

  0

  maliming created one month ago

  Support Team Fullstack Developer

  hi

  There is a problem when checking the handler type. If no handler is found, the Processed will be set to true

  Please add a MyProxyHelper to resolve the problem. https://github.com/abpframework/abp/pull/23545

  Thanks.

  public static class MyProxyHelper
  {
      private const string ProxyNamespace = "Castle.Proxies";
  
      public static Type GetUnProxiedType(Type type)
      {
          return type.Namespace == ProxyNamespace ? type.GetTypeInfo().BaseType! : type;
      }
  }
  

  

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  0

  neethucp created one month ago

  Hi, we’ve tested this in the sample project and it’s working as expected. However, in our main project, we don’t have a HandleSelector configured, and setting it up might be difficult due to the number of events and the fact that our event handlers are in a separate project. The handlers also persist data to both Entity Framework and MongoDB. Is there an alternative way to test this setup without configuring HandleSelector?

  Also, we’re wondering about error handling:

  • If an event handler throws an exception, will the system keep retrying indefinitely?
  • Is there a way to mark the event as failed after a maximum number of retries?
  • And will a failed event block subsequent events from being processed?

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• 

  0

  maliming created one month ago

  Support Team Fullstack Developer

  hi

  You don't need to set HandleSelector in microservices. Monolithic Application need it.

  If an event handler throws an exception, will the system keep retrying indefinitely?

  Yes, InboxProcessManager is IBackgroundWorker, Will try to get inbox message and execute the handlers.

  Is there a way to mark the event as failed after a maximum number of retries?

  The built-in processing service does not support this feature.

  And will a failed event block subsequent events from being processed?

  Yes, Multiple events can get blocked in a project/microservice.

  I will try to make some changes to prevent blocking others' events.

  Thanks.

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• 

  0

  neethucp created one month ago

  So how can we test this in our microservice project? Do we need to upgrade the packages to v9.3?

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  0

  maliming created one month ago

  Support Team Fullstack Developer

  hi

  If you don't need to use HandleSelector, then you don't need to yograde packages.

  • If your event handler is not invoked, the Processed will be true.
  • If your event handler is invoked without exceptions, the Processed will be true.
  • If your event handler is invoked and throws any exceptions, the Processed will be false.

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