xinghuayu007 opened a new issue #6631:
URL: https://github.com/apache/incubator-doris/issues/6631


   ### Search before asking
   
   - [X] I had searched in the 
[issues](https://github.com/apache/incubator-doris/issues?q=is%3Aissue) and 
found no similar issues.
   
   
   ### Description
   
   A query may need to scan data from many nodes. If one node scans data very 
slowly, It will delay the whole query. As no resource isolation in Doris, one 
node will become `Slow Node` very common because of high cpu load or memory 
exhaustion.   For the users, they find the same query finished with different 
time cost. On the other hand, as no `Fail Tolerant`, for a big query, a node 
failed  will cause the whole query failed. It will cost a lot time to begin a 
new query.
   
   In a word, a slow node or failed node will delay the whole query. How to 
solve this problem?
   
   **Hedged Request** is a method to handle long tail problem. Very time, it 
will create multiple queries to different replications. It chooses the first 
one fasted returned query and cancel other queries. It only need another more 
than 5% load to assure the request stable. 
   
   Doris hash many replications for one table. Therefore,  Hedged Request can 
be implemented in Doris to make query stable. That is important for Real-Time 
BI Report. 
   
   ### Use case
   
   This feature is suitable for users who want stable query performance.
   
   ### Related issues
   
   _No response_
   
   ### Are you willing to submit PR?
   
   - [X] Yes I am willing to submit a PR!
   
   ### Code of Conduct
   
   - [X] I agree to follow this project's [Code of 
Conduct](https://www.apache.org/foundation/policies/conduct)
   


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