Hi folks, we've been upgrading clusters from 2.0 to 2.2 recently and we've noticed that debug logging was causing serious performance issues in some cases, specifically because of its use in the query pager.
I've opened a ticket with some benchmarks and flame graphs : https://issues.apache.org/jira/browse/CASSANDRA-14318 The problem should be less serious in the read path with Cassandra 3.0 and above as the query pager code has been reworked and doesn't log at debug level. I think that debug logging shouldn't be turned on by default though, since we see it doesn't come for free and that it lowers read performance in 2.2. Was there any specific reason why it was enabled by default in 2.2 ? Is anyone opposed to disabling debug logging by default in all branches ? -- ----------------- Alexander Dejanovski France @alexanderdeja Consultant Apache Cassandra Consulting http://www.thelastpickle.com
