Possible Bug in Ncqrs.EventBus

[theBoringCoder]

I think I may have found a bug, but I can't put my finger on the exact cause.  Steps to reproduce:

• Configure and run the MyNotes sample
• Add a new note
• Edit note #1
• Edit note #1 a second time
• Edit note #1 a third time
• Add a new note
• Stop the MyNotes sample
• Run these queries
• SELECT * FROM [MyNotesEventStore].[dbo].[EventSources]
• SELECT * FROM [MyNotesEventStore].[dbo].[Events]
• SELECT * FROM [Snapshots]
• SELECT * FROM [PipelineState]
• Note that the sequential order of the [PipelineState] table matches the sequential order of what you did when you ran the app, and the sequential order of the [Events] table
• Run these queries
• TRUNCATE TABLE [MyNotesReadModel].[dbo].[NoteItemSet]
• TRUNCATE TABLE [MyNotesReadModel].[dbo].[TotalsPerDayItemSet]
• TRUNCATE TABLE [MyNotesEventStore].[dbo].[PipelineState]
• Run the MyNotes sample
• Notice that when the ApplicationService starts up, it replays the events in the wrong order
• Do not add any new notes or change the text of any existing notes
• Stop the MyNotes sample
• Run these queries
• SELECT * FROM [MyNotesEventStore].[dbo].[EventSources]
• SELECT * FROM [MyNotesEventStore].[dbo].[Events]
• SELECT * FROM [Snapshots]
• SELECT * FROM [PipelineState]
• Notice that the order of the entries in [PipelineState] is incorrect
• Run the MyNotes sample
• Notice that the ApplicationService reprocesses the Event with a SequentialId of 5--because the last entry in [PipelineState] indicates that the last event processed was the Event with a SequentialId of 4.

I've spent a few hours tracing through the code, and I *think* (remember, I said I couldn't put my finger on the cause) the problem is in either the Pipeline or Demultiplexer.

 

I'd be much abliged if someone could look at this and figure out what the problem is.

 

thanks,

 

Tom

theBoringCoder

[Pieter Joost van de Sande]

I can take a look at this at the end of this week, early next week.

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[theBoringCoder]

Super. I figured out a little more of what's going on--apologies, I'm not very good at debugging multi-threaded scenarios: In Ncqrs.EventBus.MsSqlServerEventStoreElementStore, when you are replaying all the events in the database, the events arrive out of order to the MarkLastProcessedElement() method.  This causes the data in the PipelineState table to be out of order with regards to the data in the Event table.

[tcbo...@gmail.com]

Anyone see a resolution for this problem?

 

Sent from Windows Mail

 

[Alex Pollan]

I repeated these steps and couldn't reproduce the problem.

All was fine in my test.

Someone had fixed the problem?