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https://issues.apache.org/jira/browse/CASSANDRA-21623?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=18115087#comment-18115087
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Michael Semb Wever commented on CASSANDRA-21623:
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CI: pre-commit profile: https://astro-cass.ci/job/cassandra/33
> Report the number of rows replica filtering protection cached when it warns
> ---------------------------------------------------------------------------
>
> Key: CASSANDRA-21623
> URL: https://issues.apache.org/jira/browse/CASSANDRA-21623
> Project: Apache Cassandra
> Issue Type: Improvement
> Components: Consistency/Coordination
> Reporter: Michael Semb Wever
> Priority: Normal
> Fix For: 6.0.x, 7.x
>
> Attachments: ci_summary (3).html, results_details (3).tar.xz
>
> Time Spent: 10m
> Remaining Estimate: 0h
>
> Replica filtering protection warns when it caches more rows than
> {{cached_replica_rows_warn_threshold}}:
> {code}
> Replica filtering protection has cached over 5 rows during query SELECT *
> FROM ks.tbl WHERE v = 'old' LIMIT 9 ALLOW FILTERING. (See
> 'cached_replica_rows_warn_threshold' in cassandra.yaml.)
> {code}
> The message names the threshold, not the number of rows cached, so an
> operator cannot tell a query that went one row over from one that went a
> thousand rows over. The two need different responses: the first argues for
> raising the threshold, the second for fixing the query.
> The warning is also raised as the count crosses the threshold, which is
> before the query reaches its high watermark, and the count the warning would
> want is not known until the query ends.
> The patch moves the warning to the end of the query, where {{maxRowsCached}}
> is the high watermark the metric already records, and names that number:
> {code}
> Replica filtering protection has cached up to 6 rows during query SELECT *
> FROM ks.tbl WHERE v = 'old' LIMIT 9 ALLOW FILTERING, which is over the
> warning threshold of 5 rows defined by 'cached_replica_rows_warn_threshold'
> in cassandra.yaml.
> {code}
> The failure message gains the count the same way. The failure threshold stays
> on every increment, so an overloaded query still aborts at the row that
> crosses it, and the warning is suppressed once the failure has fired, so one
> query raises one message.
> The {{hitWarningThreshold}} field goes away, and its comment with it: the
> comment claimed the field tracked a partition, while nothing ever reset it,
> so the warning was already once per query.
> Patch:
> [mck/CASSANDRA-21623/trunk|https://github.com/thelastpickle/cassandra/tree/mck/CASSANDRA-21623/trunk]
> Provenance:
> [b8bd9b19ce|https://github.com/datastax/cassandra/commit/b8bd9b19ce72c4f4d1f912ccc03fd62a59cbd2fc]
> by [~adelapena]. That commit left a commented-out duplicate line in the
> test, which this patch drops.
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