DateTieredCompactionStrategy (DTCS) is not working as expected, its optimizations are being defeated in our environment(s) by out-of-order writes (see {T126221}, for background). An alternative to DTCS has emerged in the form of [[ https://github.com/jeffjirsa/twcs | TimeWindowCompactionStrategy ]] (TWCS), which eschews tiering in favor of creating fixed windows of time.
Since time-ordered data models are common in our environment(s), I believe TWCS warrants an investigation.
== Status ==
Tables that have been converted to date.
| Conversion date | Tables | |
|---------------------|---------|--|
| 2016-10-12 | local_group_wiktionary_T_parsoid_html.data | [[ https://grafana.wikimedia.org/dashboard/snapshot/3RQD7qLJ6ZDNCD6Urj2Lv5etFrMDmKIr | SSTables/read ]], [[ https://grafana.wikimedia.org/dashboard/snapshot/EwiQVBstxOPw14tQLNeWuplRR3VQ5nyb | SSTable count ]] (large spikes are the result of repair testing) |
| 2016-10-13 | local_group_wikimedia_T_parsoid_html.data | [[ https://grafana.wikimedia.org/dashboard/snapshot/3x7zFqITnyJOkn2ezZB4GLObRmMca1x5 | SSTables/read ]], [[ https://grafana.wikimedia.org/dashboard/snapshot/dwiuDOR1iLfDnu2jf8u03P5O3TdgUBYr | SSTable count ]]|
| 2016-10-19 | local_group_wikipedia_T_parsoid_html.data | [[ https://grafana.wikimedia.org/dashboard/snapshot/kNFqFBZu4PksvvUu1TGV1toGkozxTD5L | SSTables/read ]]. [[ https://grafana.wikimedia.org/dashboard/snapshot/7eI9PnS4yDNO7TRjUB3KcuvG7c8yaBLs | SSTable count ]] |
| 2016-10-27 | local_group_*_T_mobileapps_{lead,remaining}.data | |
| 2016-11-07 | local_group_*_T_title__revisions.{data,idx_by_rev_ever} | |
----
* http://www.slideshare.net/JeffJirsa1/cassandra-summit-2015-real-world-dtcs-for-operators
* {T126221}
* [[ https://issues.apache.org/jira/browse/CASSANDRA-9666 | CASSANDRA-9666 ]]
* https://github.com/jeffjirsa/twcs
* {T113805} (closely related)