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https://issues.apache.org/jira/browse/CASSANDRA-20843?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=18015567#comment-18015567
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Ling Mao commented on CASSANDRA-20843:
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Assign to me, I will make _*cached_rows*_ as guardrail and correct related 
yaml/doc/comment/UT tonight

> Replica filtering guardrail needs a change in the yaml
> ------------------------------------------------------
>
>                 Key: CASSANDRA-20843
>                 URL: https://issues.apache.org/jira/browse/CASSANDRA-20843
>             Project: Apache Cassandra
>          Issue Type: Bug
>          Components: Local/Config
>            Reporter: Paul Ayers
>            Priority: Normal
>              Labels: 5.0.5
>             Fix For: 4.0.x, 4.1.x, 5.0.x, 6.x
>
>
> In the Cassandra 5 cassandra.yaml, we have the following guardrail section:
> {code:java}
> # Filtering and secondary index queries at read consistency levels above 
> ONE/LOCAL_ONE use a
> # mechanism called replica filtering protection to ensure that results from 
> stale replicas do
> # not violate consistency. (See CASSANDRA-8272 and CASSANDRA-15907 for more 
> details.) This
> # mechanism materializes replica results by partition on-heap at the 
> coordinator. The more possibly
> # stale results returned by the replicas, the more rows materialized during 
> the query.
> replica_filtering_protection:
>     # These thresholds exist to limit the damage severely out-of-date 
> replicas can cause during these
>     # queries. They limit the number of rows from all replicas individual 
> index and filtering queries
>     # can materialize on-heap to return correct results at the desired read 
> consistency level.
>     #
>     # "cached_replica_rows_warn_threshold" is the per-query threshold at 
> which a warning will be logged.
>     # "cached_replica_rows_fail_threshold" is the per-query threshold at 
> which the query will fail.
>     #
>     # These thresholds may also be adjusted at runtime using the 
> StorageService mbean.
>     #
>     # If the failure threshold is breached, it is likely that either the 
> current page/fetch size
>     # is too large or one or more replicas is severely out-of-sync and in 
> need of repair.
>     cached_rows_warn_threshold: 2000
>     cached_rows_fail_threshold: 32000
> {code}
> This is confusing for some as we had a customer attempt to configure 
> cached_replica_rows_warn_threshold and cached_replica_rows_fail_threshold in 
> addition to the actual parameters. We should update the wording so the 
> description matches the parameters.



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