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mishra.anurag643_153409 avatar image
mishra.anurag643_153409 asked ·

read repair mentioned in data stax documentation differs mentioned in apache cassandra documentation for consistency level one

in datastax documentation it is mentioned read repair happens for consistency level one , even there is one quiz on this in DS-201 . I have attached image for that .


1609956055901.pngbelow link is from apache cassandra :

https://cassandra.apache.org/doc/latest/operating/read_repair.html


please refer screenshot attached below and notice highlighted part .


1609956153646.png


also in apache cassandra documentation it is mentioned . "If read repair is performed it is made only on the replicas that are not up-to-date and that are involved in the read request. The number of replicas involved in a read request would be based on the read consistency level ."

above line stats that only those many replicas are checked in numbers as the per the consistency level set . So if consistency level is set to ONE . Only one replica will be checked and data will be sent to client .

read repair
1609956055901.png (14.7 KiB)
1609956153646.png (59.0 KiB)
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1 Answer

Erick Ramirez avatar image
Erick Ramirez answered ·

Read repair does not take place for consistency of ONE or LOCAL_ONE.

It's interesting that you claim the docs state otherwise but you didn't provide the link so I don't know what you're referring to. Cheers!

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