[CASSANDRA-14194] Chain commit log marker potential performance regression in batch commit mode

• Type: Bug
• Status: Resolved
• Priority: Normal
• Resolution: Fixed
• Fix Version/s: 3.0.17, 3.11.3, 4.0-alpha1, 4.0
• Component/s: Legacy/Core, Legacy/Testing
• Severity: Normal
• Assignee: Jason Brown
• Reporter: Ariel Weisberg

Authors

Jason Brown

Reviewers

Ariel Weisberg

• Created: 26/Jan/18 18:37
• Updated: 15/May/20 08:06
• Resolved: 05/Mar/18 22:39

Description

CASSANDRA-13987 modified how the commit log sync thread works. I noticed that cql3.ViewTest and ViewBuilderTaskTest have been timing out, but only in CircleCI. When I jstack in CircleCI what I see is that the commit log writer thread is parked and the threads trying to append to the commit log are blocked waiting on it.

I tested the commit before 13987 and it passed in CircleCI and then I tested with 13987 and it timed out. I suspect this may be a general performance regression and not just a CircleCI issue.

And this is with write barriers disabled (sync thread doesn't actually sync) so it wasn't blocked in the filesystem.

Issue Links

• is caused by: CASSANDRA-13987 Multithreaded commitlog subtly changed durability