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Peter Schuller commented on CASSANDRA-1968: ------------------------------------------- Hmmm. The young gen will also directly affect the pause times for most collection pauses, as I'm sure you're aware. Depending on total heap size and depending on CPU count, 1/4 heap going to young gen might be huge and cause significant pause times. It's certainly expected that larger young gens, up to a point, increase performance by avoiding promotion to old-gen, but should the out-of-the-box settings be so aggressive given the potential effects on latency? How about something like min(max_sensible_default, 1/4 heap size) or perhaps min(max_sensible_per_modern_cpu_core*num_cores, 1/4 heap size)? > Increase JVM young generation size > ---------------------------------- > > Key: CASSANDRA-1968 > URL: https://issues.apache.org/jira/browse/CASSANDRA-1968 > Project: Cassandra > Issue Type: Improvement > Affects Versions: 0.7.0 > Reporter: Brandon Williams > Assignee: Brandon Williams > Fix For: 0.7.1 > > Attachments: 1968.txt > > > Increasing the young generation size has a profound effect on performance and > cpu utilization. We should set it explicitly. -- This message is automatically generated by JIRA. - You can reply to this email to add a comment to the issue online.