[jira] [Updated] (CASSANDRA-9829) Dynamically adjust LCS level sizes
[ https://issues.apache.org/jira/browse/CASSANDRA-9829?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel ] C. Scott Andreas updated CASSANDRA-9829: Component/s: Compaction > Dynamically adjust LCS level sizes > -- > > Key: CASSANDRA-9829 > URL: https://issues.apache.org/jira/browse/CASSANDRA-9829 > Project: Cassandra > Issue Type: New Feature > Components: Compaction >Reporter: Jonathan Ellis >Priority: Major > Labels: compaction, lcs, performance > Fix For: 4.x > > > LCS works best when the top level is full. Then 90% of reads can be served > from a single sstable. By contrast if the top level is only 10% full then > 90% of reads will be served from two. This results in worse performance as > well as confused users. > To address this, we can adjust the ideal top level size to how much data is > actually in it (and set each corresponding lower level to 1/10 of the next > one above). > (This is an idea [from > rocksdb|https://www.reddit.com/r/IAmA/comments/3de3cv/we_are_rocksdb_engineering_team_ask_us_anything/ct4asen].) -- This message was sent by Atlassian JIRA (v7.6.3#76005) - To unsubscribe, e-mail: commits-unsubscr...@cassandra.apache.org For additional commands, e-mail: commits-h...@cassandra.apache.org
[jira] [Updated] (CASSANDRA-9829) Dynamically adjust LCS level sizes
[ https://issues.apache.org/jira/browse/CASSANDRA-9829?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel ] Wei Deng updated CASSANDRA-9829: Labels: compaction lcs performance (was: compaction performance) > Dynamically adjust LCS level sizes > -- > > Key: CASSANDRA-9829 > URL: https://issues.apache.org/jira/browse/CASSANDRA-9829 > Project: Cassandra > Issue Type: New Feature >Reporter: Jonathan Ellis > Labels: compaction, lcs, performance > Fix For: 3.x > > > LCS works best when the top level is full. Then 90% of reads can be served > from a single sstable. By contrast if the top level is only 10% full then > 90% of reads will be served from two. This results in worse performance as > well as confused users. > To address this, we can adjust the ideal top level size to how much data is > actually in it (and set each corresponding lower level to 1/10 of the next > one above). > (This is an idea [from > rocksdb|https://www.reddit.com/r/IAmA/comments/3de3cv/we_are_rocksdb_engineering_team_ask_us_anything/ct4asen].) -- This message was sent by Atlassian JIRA (v6.3.4#6332)
[jira] [Updated] (CASSANDRA-9829) Dynamically adjust LCS level sizes
[ https://issues.apache.org/jira/browse/CASSANDRA-9829?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel ] Paulo Motta updated CASSANDRA-9829: --- Assignee: (was: Paulo Motta) > Dynamically adjust LCS level sizes > -- > > Key: CASSANDRA-9829 > URL: https://issues.apache.org/jira/browse/CASSANDRA-9829 > Project: Cassandra > Issue Type: New Feature >Reporter: Jonathan Ellis > Labels: compaction, performance > Fix For: 3.x > > > LCS works best when the top level is full. Then 90% of reads can be served > from a single sstable. By contrast if the top level is only 10% full then > 90% of reads will be served from two. This results in worse performance as > well as confused users. > To address this, we can adjust the ideal top level size to how much data is > actually in it (and set each corresponding lower level to 1/10 of the next > one above). > (This is an idea [from > rocksdb|https://www.reddit.com/r/IAmA/comments/3de3cv/we_are_rocksdb_engineering_team_ask_us_anything/ct4asen].) -- This message was sent by Atlassian JIRA (v6.3.4#6332)
[jira] [Updated] (CASSANDRA-9829) Dynamically adjust LCS level sizes
[ https://issues.apache.org/jira/browse/CASSANDRA-9829?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel ] Jonathan Ellis updated CASSANDRA-9829: -- Labels: compaction performance (was: ) > Dynamically adjust LCS level sizes > -- > > Key: CASSANDRA-9829 > URL: https://issues.apache.org/jira/browse/CASSANDRA-9829 > Project: Cassandra > Issue Type: New Feature > Components: Core >Reporter: Jonathan Ellis >Assignee: Paulo Motta > Labels: compaction, performance > Fix For: 3.x > > > LCS works best when the top level is full. Then 90% of reads can be served > from a single sstable. By contrast if the top level is only 10% full then > 90% of reads will be served from two. This results in worse performance as > well as confused users. > To address this, we can adjust the ideal top level size to how much data is > actually in it (and set each corresponding lower level to 1/10 of the next > one above). > (This is an idea [from > rocksdb|https://www.reddit.com/r/IAmA/comments/3de3cv/we_are_rocksdb_engineering_team_ask_us_anything/ct4asen].) -- This message was sent by Atlassian JIRA (v6.3.4#6332)
