Christian Spriegel created CASSANDRA-4917: ---------------------------------------------
Summary: Optimize tombstone creation for ExpiringColumns Key: CASSANDRA-4917 URL: https://issues.apache.org/jira/browse/CASSANDRA-4917 Project: Cassandra Issue Type: Improvement Components: Core Reporter: Christian Spriegel The goal of this ticket is to reduce the amount of tombstones created from ExpiringColumns. Currently tombstones will always stay a full gc_grace time, which is not neccessary for ExpiringColumns. We only need to ensure that ExpiringColumn and tombstone together live as long as gc_grace. If the ExpiringColumn's TTL>=gc_grace then we can create an already gcable tombstone and drop that instantly. My initial proposal was to use the ExpiringColumns creation-timestamp as deletiontime for the tombstone, but Sylvain pointed out that we should not mix local and client timestamps. So I changed it to this: {code} public static Column create(ByteBuffer name, ByteBuffer value, long timestamp, int timeToLive, int localExpirationTime, int expireBefore, IColumnSerializer.Flag flag) { if (localExpirationTime >= expireBefore || flag == IColumnSerializer.Flag.PRESERVE_SIZE) return new ExpiringColumn(name, value, timestamp, timeToLive, localExpirationTime); // the column is now expired, we can safely return a simple tombstone return new DeletedColumn(name, *localExpirationTime-timeToLive*, timestamp); // return new DeletedColumn(name, localExpirationTime, timestamp); // old code } {code} This was discussed on the mailinglist: http://cassandra-user-incubator-apache-org.3065146.n2.nabble.com/repair-compaction-and-tombstone-rows-td7583481.html -- This message is automatically generated by JIRA. If you think it was sent incorrectly, please contact your JIRA administrators For more information on JIRA, see: http://www.atlassian.com/software/jira