[CASSANDRA-16465] Increased Read Latency With Cassandra >= 3.11.7

• Type: Bug
• Status: Open
• Priority: Normal
• Resolution: Unresolved
• Fix Version/s: 3.11.x, 4.0.x
• Component/s: Legacy/Local Write-Read Paths
• Bug Category: Degradation - Performance Bug/Regression
• Severity: Normal
• Complexity: Normal
• Discovered By: User Report
• Platform: All
• Assignee: Unassigned
• Reporter: Ahmed ELJAMI
• Created: 22/Feb/21 09:31
• Updated: 29/Jul/21 19:39

Description

After upgrading Cassandra from 3.11.3 to 3.11.9, Cassandra read latency 99% increased significantly. Getting back to 3.11.3 immediately fixed the issue.

I have observed "SStable reads" increases after upgrading to 3.11.9.

The same behavior was observed by some other users: https://www.mail-archive.com/[e-mail]/msg61247.html

According to Paulo Motta's comment, this behavior may be caused by https://issues.apache.org/jira/browse/CASSANDRA-15690 which was introduced on 3.11.7 and removed an optimization that may cause a correctness issue when there are partition deletions.