[GitHub] [pulsar] wenbingshen opened a new issue #14559: Ignoring flow control message when resetCursorInProgress=TRUE

[GitBox]

wenbingshen opened a new issue #14559:
URL: https://github.com/apache/pulsar/issues/14559


   **Describe the bug**
   
   1. Our broker is highly busy
   
![image](https://user-images.githubusercontent.com/35599757/156730401-5968b62f-5ce0-4c43-ad3f-04f7433855ec.png)
   
   2. Our business uses `Reader` for consumption, in which `seek` operations 
are often performed.
   3. In the `seek` operation of pulsar, there will be a process of actively 
disconnecting the consumer and canceling the currently reading operation.
   <img width="1437" alt="image" 
src="https://user-images.githubusercontent.com/35599757/156738988-ee032278-7c84-4346-9126-3ef43f665226.png";>
   
   4. Next, whether the `seek` operation is completed or not, the client has 
the right to subscribe the subscription.
   <img width="1439" alt="image" 
src="https://user-images.githubusercontent.com/35599757/156739047-05bea0f0-7d06-436c-ab3a-f593aa339f94.png";>
   
   5. Because the server thread pool is busy, the `seek` operation is delayed. 
The client first subscribed a subscription and initiates a `FLOW` request, 
causing the broker to start reading data.
   <img width="1439" alt="image" 
src="https://user-images.githubusercontent.com/35599757/156739353-10d9701f-3df4-4573-aa18-e4f4349b874c.png";>
   
   
   6. Next, the seek operation is completed, and the positions of `md position` 
and `rd position` are reset to the seek position.
   <img width="1439" alt="image" 
src="https://user-images.githubusercontent.com/35599757/156739594-e36b57d2-1f6d-4bb2-b292-b035f594d293.png";>
   
   7. Then, the read operation is completed, after the data is sent to the 
client, the client executes ack, and md and rd are set to a certain position of 
the message read by the client.
   <img width="1439" alt="image" 
src="https://user-images.githubusercontent.com/35599757/156739816-f7bad25a-ad94-40d5-83b5-cc4b5ff35cac.png";>
   
   
   8. Next, the seek operation is completed, and the positions of `md position` 
and `rd position` are reset to the seek position.
   <img width="1439" alt="image" 
src="https://user-images.githubusercontent.com/35599757/156740044-fbb730cf-1070-4431-9add-fd9ec0efe5ec.png";>
   
   9. Then, the read operation is completed, after the data is sent to the 
client, the client executes ack, and md and rd are set to a certain position of 
the message read by the client.
   <img width="1438" alt="image" 
src="https://user-images.githubusercontent.com/35599757/156739952-aa9dbf29-0a2e-487a-b5af-189d029cd0bf.png";>
   
   
   The entire execution flow is shown in the following figure:
   
![image](https://user-images.githubusercontent.com/35599757/156738780-025f94c9-c016-4c1c-b2ba-a0e5b7a59e38.png)
   


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