[ https://issues.apache.org/jira/browse/CASSANDRA-3168?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel ]
Jonathan Ellis updated CASSANDRA-3168: -------------------------------------- Attachment: 3168.txt patch to remove allocator.size() from getLiveSize calculation. also adds note about arena allocation to NEWS. > Arena allocation causes excessive flushing on small heaps > --------------------------------------------------------- > > Key: CASSANDRA-3168 > URL: https://issues.apache.org/jira/browse/CASSANDRA-3168 > Project: Cassandra > Issue Type: Bug > Affects Versions: 1.0 > Reporter: Jonathan Ellis > Assignee: Jonathan Ellis > Fix For: 1.0 > > Attachments: 3168.txt > > > adding allocator.size() to Memtable.getLiveSize has two problems: > 1) it double-counts allocated parts of regions > 2) it makes the size of an empty memtable the size of a single region > (2) is a particular problem because flushing a nearly-empty memtable will not > actually free up much memory -- we just trade one almost-empty region, for > another. In testing, I even saw this happening to the low-traffic system > tables like LocationInfo. -- This message is automatically generated by JIRA. For more information on JIRA, see: http://www.atlassian.com/software/jira