OpenBitSet can allocate more bytes than it needs ------------------------------------------------
Key: CASSANDRA-3618 URL: https://issues.apache.org/jira/browse/CASSANDRA-3618 Project: Cassandra Issue Type: Bug Components: Core Affects Versions: 1.0.0 Reporter: Sylvain Lebresne Assignee: Sylvain Lebresne Fix For: 1.0.7 CASSANDRA-2466 changed OpenBitSet to break big long arrays into pages. However, it always allocate full pages, each page being of size 4096 * 8 bytes. This means that we almost always allocate too much bytes, and for a row that has 1 column, the associated row bloom filter allocates 32760 more bytes than it should. This has a significant impact on performance. In a small test using the SSTableSimpleUnsortedWriter to generate rows with 1 column, 0.8 is about twice as fast as 1.0 because of that (the difference shrink when there is more columns obviously). -- This message is automatically generated by JIRA. If you think it was sent incorrectly, please contact your JIRA administrators: https://issues.apache.org/jira/secure/ContactAdministrators!default.jspa For more information on JIRA, see: http://www.atlassian.com/software/jira