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mishra.anurag643_153409 avatar image
mishra.anurag643_153409 asked Erick Ramirez edited

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
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Erick Ramirez avatar image
Erick Ramirez answered Erick Ramirez edited

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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