[jira] [Updated] (CASSANDRA-13561) Purge TTL on expiration
[ https://issues.apache.org/jira/browse/CASSANDRA-13561?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel ] Andrew Whang updated CASSANDRA-13561: - Resolution: Duplicate Status: Resolved (was: Patch Available) > Purge TTL on expiration > --- > > Key: CASSANDRA-13561 > URL: https://issues.apache.org/jira/browse/CASSANDRA-13561 > Project: Cassandra > Issue Type: New Feature >Reporter: Andrew Whang >Assignee: Andrew Whang >Priority: Minor > Fix For: 4.0 > > > Tables with mostly TTL columns tend to suffer from high droppable tombstone > ratio, which results in higher read latency, cpu utilization, and disk usage. > Expired TTL data become tombstones, and the nature of purging tombstones > during compaction (due to checking for overlapping SSTables) make them > susceptible to surviving much longer than expected. A table option to purge > TTL on expiration would address this issue, by preventing them from becoming > tombstones. A boolean purge_ttl_on_expiration table setting would allow users > to easily turn the feature on or off. > Being more aggressive with gc_grace could also address the problem of long > lasting tombstones, but that would affect tombstones from deletes as well. > Even if a purged [expired] cell is revived via repair from a node that hasn't > yet compacted away the cell, it would be revived as an expiring cell with the > same localDeletionTime, so reads should properly handle them. As well, it > would be purged in the next compaction. -- This message was sent by Atlassian JIRA (v6.4.14#64029) - To unsubscribe, e-mail: commits-unsubscr...@cassandra.apache.org For additional commands, e-mail: commits-h...@cassandra.apache.org
[jira] [Updated] (CASSANDRA-13561) Purge TTL on expiration
[ https://issues.apache.org/jira/browse/CASSANDRA-13561?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel ] Andrew Whang updated CASSANDRA-13561: - Fix Version/s: 4.0 Status: Patch Available (was: Open) Patch here https://github.com/whangsf/cassandra/commit/6f46e18988122f80608b1f5ba4a3d5c5dbbe1c61 > Purge TTL on expiration > --- > > Key: CASSANDRA-13561 > URL: https://issues.apache.org/jira/browse/CASSANDRA-13561 > Project: Cassandra > Issue Type: New Feature >Reporter: Andrew Whang >Priority: Minor > Fix For: 4.0 > > > Tables with mostly TTL columns tend to suffer from high droppable tombstone > ratio, which results in higher read latency, cpu utilization, and disk usage. > Expired TTL data become tombstones, and the nature of purging tombstones > during compaction (due to checking for overlapping SSTables) make them > susceptible to surviving much longer than expected. A table option to purge > TTL on expiration would address this issue, by preventing them from becoming > tombstones. A boolean purge_ttl_on_expiration table setting would allow users > to easily turn the feature on or off. > Being more aggressive with gc_grace could also address the problem of long > lasting tombstones, but that would affect tombstones from deletes as well. > Even if a purged [expired] cell is revived via repair from a node that hasn't > yet compacted away the cell, it would be revived as an expiring cell with the > same localDeletionTime, so reads should properly handle them. As well, it > would be purged in the next compaction. -- This message was sent by Atlassian JIRA (v6.3.15#6346) - To unsubscribe, e-mail: commits-unsubscr...@cassandra.apache.org For additional commands, e-mail: commits-h...@cassandra.apache.org
