# \#compaction **URL:** https://forum.scylladb.com/tag/compaction/37.md [Latest](https://forum.scylladb.com/latest.md) · [Categories](https://forum.scylladb.com/categories.md) · [Tags](https://forum.scylladb.com/tags.md) --- ## [How do I cleanup Counter tables, without using a TTL? What is the status of Counters and Tablets? Would using TWCS make sense here?](https://forum.scylladb.com/t/how-do-i-cleanup-counter-tables-without-using-a-ttl-what-is-the-status-of-counters-and-tablets-would-using-twcs-make-sense-here/5273)
**Author:** [@Guy](https://forum.scylladb.com/u/Guy)\ **Replies:** 0\ **Last updated:** [February 9, 2026, 10:25am UTC](https://forum.scylladb.com/t/how-do-i-cleanup-counter-tables-without-using-a-ttl-what-is-the-status-of-counters-and-tablets-would-using-twcs-make-sense-here/5273 "2026-02-09T10:25:13Z")
--- ## [ScyllaDB, why is disk space not released when data are modified, compaction and how can I free up disk space?](https://forum.scylladb.com/t/scylladb-why-is-disk-space-not-released-when-data-are-modified-compaction-and-how-can-i-free-up-disk-space/5237)
**Author:** [@arbos](https://forum.scylladb.com/u/arbos)\ **Replies:** 1\ **Last updated:** [January 9, 2026, 10:04am UTC](https://forum.scylladb.com/t/scylladb-why-is-disk-space-not-released-when-data-are-modified-compaction-and-how-can-i-free-up-disk-space/5237 "2026-01-09T10:04:52Z")
Installation details #ScyllaDB version: 4.6.3 #Cluster size: 3 os Ubuntu 20.04: So we had this table, let’s say it’s called mykeyspace.data\_by\_min , that has the default compaction type (size tiered). It contained … --- ## [Does disk space free automatically after reducing RF and running repair?](https://forum.scylladb.com/t/does-disk-space-free-automatically-after-reducing-rf-and-running-repair/5170)
**Author:** [@Jobin\_Jose](https://forum.scylladb.com/u/Jobin_Jose)\ **Replies:** 1\ **Last updated:** [November 8, 2025, 6:11am UTC](https://forum.scylladb.com/t/does-disk-space-free-automatically-after-reducing-rf-and-running-repair/5170 "2025-11-08T06:11:53Z")
We reduced RF from 3→2 using ALTER KEYSPACE and ran nodetool repair on all 3 nodes. Will disk space be freed automatically through compaction? --- ## [How much disk space required when changing compaction strategy?](https://forum.scylladb.com/t/how-much-disk-space-required-when-changing-compaction-strategy/5162)
**Author:** [@Guy](https://forum.scylladb.com/u/Guy)\ **Replies:** 1\ **Last updated:** [October 30, 2025, 5:34am UTC](https://forum.scylladb.com/t/how-much-disk-space-required-when-changing-compaction-strategy/5162 "2025-10-30T05:34:08Z")
--- ## [Incremental backup, repair, compaction and disk space](https://forum.scylladb.com/t/incremental-backup-repair-compaction-and-disk-space/5114)
**Author:** [@Guy](https://forum.scylladb.com/u/Guy)\ **Replies:** 0\ **Last updated:** [September 29, 2025, 5:51am UTC](https://forum.scylladb.com/t/incremental-backup-repair-compaction-and-disk-space/5114 "2025-09-29T05:51:02Z")
--- ## [TWCS with many unique partitions](https://forum.scylladb.com/t/twcs-with-many-unique-partitions/5044)
**Author:** [@dobermangood](https://forum.scylladb.com/u/dobermangood)\ **Replies:** 2\ **Last updated:** [September 4, 2025, 6:10am UTC](https://forum.scylladb.com/t/twcs-with-many-unique-partitions/5044 "2025-09-04T06:10:15Z")
Hi, I have a table for storing user refresh tokens. CREATE TABLE IF NOT EXISTS user\_refresh\_tokens ( refresh\_token text, user\_id timeuuid, PRIMARY KEY (refresh\_token) ) WITH compaction = { 'class' : 'Tim… --- ## [Will tombstones be frequently repaired after being compressed?](https://forum.scylladb.com/t/will-tombstones-be-frequently-repaired-after-being-compressed/4755)
**Author:** [@bo\_li](https://forum.scylladb.com/u/bo_li)\ **Replies:** 3\ **Last updated:** [July 16, 2025, 1:54pm UTC](https://forum.scylladb.com/t/will-tombstones-be-frequently-repaired-after-being-compressed/4755 "2025-07-16T13:54:02Z")
Installation details #ScyllaDB version: 5.2.18 #Cluster size: 35 os (RHEL/CentOS/Ubuntu/AWS AMI): centos I have a 35 node 5 replica cluster and the traffic pattern involves a lot of writes and deletes through altern… --- ## [Throttling of compaction, using configuration parameters](https://forum.scylladb.com/t/throttling-of-compaction-using-configuration-parameters/4789)
**Author:** [@Guy](https://forum.scylladb.com/u/Guy)\ **Replies:** 0\ **Last updated:** [April 29, 2025, 4:22am UTC](https://forum.scylladb.com/t/throttling-of-compaction-using-configuration-parameters/4789 "2025-04-29T04:22:34Z")
--- ## [Unexpected Behavior with TimeWindowCompactionStrategy in ScyllaDB 6.2 Open Source](https://forum.scylladb.com/t/unexpected-behavior-with-timewindowcompactionstrategy-in-scylladb-6-2-open-source/4345)
**Author:** [@Naman\_kaushik1](https://forum.scylladb.com/u/Naman_kaushik1)\ **Replies:** 2\ **Last updated:** [April 24, 2025, 8:25am UTC](https://forum.scylladb.com/t/unexpected-behavior-with-timewindowcompactionstrategy-in-scylladb-6-2-open-source/4345 "2025-04-24T08:25:28Z")
Hi Community, I’m using ScyllaDB 6.1 Open Source and have a table configured to store 30 days of data with the following compaction strategy: compaction = { \*\* ‘class’: ‘TimeWindowCompactionStrategy’,\*\* \*\* ‘compact… --- ## [Mutliple Datacenter cluster, diagnosing high latency spike and performance issues](https://forum.scylladb.com/t/mutliple-datacenter-cluster-diagnosing-high-latency-spike-and-performance-issues/4749)
**Author:** [@Guy](https://forum.scylladb.com/u/Guy)\ **Replies:** 0\ **Last updated:** [April 20, 2025, 8:12am UTC](https://forum.scylladb.com/t/mutliple-datacenter-cluster-diagnosing-high-latency-spike-and-performance-issues/4749 "2025-04-20T08:12:57Z")
--- ## [Compaction task occurred bad\_alloc when there is large partition](https://forum.scylladb.com/t/compaction-task-occurred-bad-alloc-when-there-is-large-partition/4631)
**Author:** [@qiuqiu](https://forum.scylladb.com/u/qiuqiu)\ **Replies:** 1\ **Last updated:** [April 15, 2025, 12:50pm UTC](https://forum.scylladb.com/t/compaction-task-occurred-bad-alloc-when-there-is-large-partition/4631 "2025-04-15T12:50:47Z")
Installation details #ScyllaDB version: 5.2.13 #Cluster size: os (RHEL/CentOS/Ubuntu/AWS AMI): CentOS Is there any potential risk in large partitions or rows or cells if do compaction, or others? Actually, a node i… --- ## [System batchlog table, tombstones compactions and effect on performance](https://forum.scylladb.com/t/system-batchlog-table-tombstones-compactions-and-effect-on-performance/4645)
**Author:** [@Guy](https://forum.scylladb.com/u/Guy)\ **Replies:** 0\ **Last updated:** [March 24, 2025, 4:57am UTC](https://forum.scylladb.com/t/system-batchlog-table-tombstones-compactions-and-effect-on-performance/4645 "2025-03-24T04:57:08Z")
--- ## [Tombstones, gc\_grace\_seconds, propagation\_delay\_in\_seconds, TWCS, compaction and related questions](https://forum.scylladb.com/t/tombstones-gc-grace-seconds-propagation-delay-in-seconds-twcs-compaction-and-related-questions/4064)
**Author:** [@Guy](https://forum.scylladb.com/u/Guy)\ **Replies:** 0\ **Last updated:** [December 4, 2024, 4:32am UTC](https://forum.scylladb.com/t/tombstones-gc-grace-seconds-propagation-delay-in-seconds-twcs-compaction-and-related-questions/4064 "2024-12-04T04:32:19Z")
--- ## [Does tombstone blocks shadowed data SSTables from being purged in TWCS](https://forum.scylladb.com/t/does-tombstone-blocks-shadowed-data-sstables-from-being-purged-in-twcs/3205)
**Author:** [@Artem\_Golovko](https://forum.scylladb.com/u/Artem_Golovko)\ **Replies:** 1\ **Last updated:** [November 22, 2024, 4:52am UTC](https://forum.scylladb.com/t/does-tombstone-blocks-shadowed-data-sstables-from-being-purged-in-twcs/3205 "2024-11-22T04:52:12Z")
Installation details ScyllaDB version: 6.2.1 From the documentation: Avoid overwriting data and deleting data explicitly at all costs, as this can potentially block an expired SSTable from being purged, due to the che… --- ## [Safe way change table compaction strategy](https://forum.scylladb.com/t/safe-way-change-table-compaction-strategy/3163)
**Author:** [@owanio1992](https://forum.scylladb.com/u/owanio1992)\ **Replies:** 1\ **Last updated:** [November 14, 2024, 1:55pm UTC](https://forum.scylladb.com/t/safe-way-change-table-compaction-strategy/3163 "2024-11-14T13:55:32Z")
Installation details #ScyllaDB version: 5.1.19 #Cluster size: 22 #OS: ubuntu Hello everyone, My Scylla cluster version is 5.1. Due to some performance issues, I want to change the compaction strategy of certain ta… --- ## [Compaction Storm slows down Scylla](https://forum.scylladb.com/t/compaction-storm-slows-down-scylla/2958)
**Author:** [@Womsel](https://forum.scylladb.com/u/Womsel)\ **Replies:** 24\ **Last updated:** [October 7, 2024, 8:27pm UTC](https://forum.scylladb.com/t/compaction-storm-slows-down-scylla/2958 "2024-10-07T20:27:27Z")
Today we observed a weird behavior of ScyllaDB: All of a sudden, the cluster became noticeable slow. Logs were not very interesting, but showed alot of compactions going on on some nodes of the cluster. Looking into the… --- ## [SSTable Resharding, how much free disk space required?](https://forum.scylladb.com/t/sstable-resharding-how-much-free-disk-space-required/2872)
**Author:** [@Guy](https://forum.scylladb.com/u/Guy)\ **Replies:** 0\ **Last updated:** [September 10, 2024, 10:51am UTC](https://forum.scylladb.com/t/sstable-resharding-how-much-free-disk-space-required/2872 "2024-09-10T10:51:56Z")
--- ## [Data size gets larger after a compaction - Is this normal?](https://forum.scylladb.com/t/data-size-gets-larger-after-a-compaction-is-this-normal/2523)
**Author:** [@papapapadopoulos](https://forum.scylladb.com/u/papapapadopoulos)\ **Replies:** 1\ **Last updated:** [August 22, 2024, 7:48am UTC](https://forum.scylladb.com/t/data-size-gets-larger-after-a-compaction-is-this-normal/2523 "2024-08-22T07:48:29Z")
I found some compaction log records like this: compaction … 1GB to 1GB (~102% of original) in 140469ms = 9MB/s. ~10368 total partitions merged to 2459. I thought it was some rounding issue because compacted data shou… --- ## [What is tombstone\_compaction\_interval mean?](https://forum.scylladb.com/t/what-is-tombstone-compaction-interval-mean/2028)
**Author:** [@chih-hao\_wang](https://forum.scylladb.com/u/chih-hao_wang)\ **Replies:** 2\ **Last updated:** [August 19, 2024, 6:42am UTC](https://forum.scylladb.com/t/what-is-tombstone-compaction-interval-mean/2028 "2024-08-19T06:42:22Z")
I read the doc troubleshooting/pointless-compactions here is my table schema ALTER TABLE foo.bar WITH compaction = {'class' : 'LeveledCompactionStrategy','tombstone\_threshold' : 0.1,'sstable\_size\_in\_mb' : 160, 'tombs… --- ## [Spark Connector, TTL on a per-element basis within the map collection type, which compaction strategy](https://forum.scylladb.com/t/spark-connector-ttl-on-a-per-element-basis-within-the-map-collection-type-which-compaction-strategy/2297)
**Author:** [@Guy](https://forum.scylladb.com/u/Guy)\ **Replies:** 0\ **Last updated:** [July 14, 2024, 4:56am UTC](https://forum.scylladb.com/t/spark-connector-ttl-on-a-per-element-basis-within-the-map-collection-type-which-compaction-strategy/2297 "2024-07-14T04:56:14Z")
--- ## [Different running compactions between multi dc](https://forum.scylladb.com/t/different-running-compactions-between-multi-dc/2282)
**Author:** [@tg.um](https://forum.scylladb.com/u/tg.um)\ **Replies:** 1\ **Last updated:** [July 12, 2024, 3:32pm UTC](https://forum.scylladb.com/t/different-running-compactions-between-multi-dc/2282 "2024-07-12T15:32:06Z")
Hi, we’re running two clusters scyllaDB with 3 nodes. DC1 (3 nodes) DC2 (3 nodes) CREATE KEYSPACE test\_keyspace WITH replication = {‘class’: ‘NetworkTopologyStrategy’, ‘dc1’: ‘3’, ‘dc2’: ‘3’}; Table is using STCS As… --- ## [Compaction strategy best for deletion of a large number of records](https://forum.scylladb.com/t/compaction-strategy-best-for-deletion-of-a-large-number-of-records/2161)
**Author:** [@liana12](https://forum.scylladb.com/u/liana12)\ **Replies:** 1\ **Last updated:** [June 14, 2024, 6:27am UTC](https://forum.scylladb.com/t/compaction-strategy-best-for-deletion-of-a-large-number-of-records/2161 "2024-06-14T06:27:02Z")
Hello! I wanted to ask for some suggestions on what compaction strategy to use for my use case. I’m using ScyllaDB to store the data generated by running in parallel multiple scripts. These scripts can finish running in… --- ## [Hosting and operating ScyllaDB vs. Cassandra, ease of use, Compaction, Garbage Collection and complexity](https://forum.scylladb.com/t/hosting-and-operating-scylladb-vs-cassandra-ease-of-use-compaction-garbage-collection-and-complexity/2139)
**Author:** [@Guy](https://forum.scylladb.com/u/Guy)\ **Replies:** 0\ **Last updated:** [June 6, 2024, 11:28am UTC](https://forum.scylladb.com/t/hosting-and-operating-scylladb-vs-cassandra-ease-of-use-compaction-garbage-collection-and-complexity/2139 "2024-06-06T11:28:47Z")
--- ## [High Compaction at peak](https://forum.scylladb.com/t/high-compaction-at-peak/1973)
**Author:** [@sdnaffi](https://forum.scylladb.com/u/sdnaffi)\ **Replies:** 1\ **Last updated:** [May 14, 2024, 4:29pm UTC](https://forum.scylladb.com/t/high-compaction-at-peak/1973 "2024-05-14T16:29:40Z")
Hi, I want to know how to adjust compaction\_static\_shares parameter according to the load. We are experiencing high compaction running at peak read and latency increases to 5s. Help us to understand the above parameter. … --- ## [Compaction\_throughput mb\_per\_sec default value](https://forum.scylladb.com/t/compaction-throughput-mb-per-sec-default-value/1870)
**Author:** [@akshay-reddy](https://forum.scylladb.com/u/akshay-reddy)\ **Replies:** 1\ **Last updated:** [April 30, 2024, 8:24am UTC](https://forum.scylladb.com/t/compaction-throughput-mb-per-sec-default-value/1870 "2024-04-30T08:24:53Z")
What was the default value of compaction\_throughput\_mb\_per\_sec in Scylla 4.6 and did this default value change to 0 from Scylla 5.1 ? --- ## [TimeWindow Compaction Strategy, TTL, Tombstones, and window size](https://forum.scylladb.com/t/timewindow-compaction-strategy-ttl-tombstones-and-window-size/1485)
**Author:** [@Guy](https://forum.scylladb.com/u/Guy)\ **Replies:** 0\ **Last updated:** [April 15, 2024, 6:31pm UTC](https://forum.scylladb.com/t/timewindow-compaction-strategy-ttl-tombstones-and-window-size/1485 "2024-04-15T18:31:07Z")
--- ## [Is there any problem with adding new parameters to sstable metadata?](https://forum.scylladb.com/t/is-there-any-problem-with-adding-new-parameters-to-sstable-metadata/1469)
**Author:** [@bybywph](https://forum.scylladb.com/u/bybywph)\ **Replies:** 6\ **Last updated:** [April 15, 2024, 10:13am UTC](https://forum.scylladb.com/t/is-there-any-problem-with-adding-new-parameters-to-sstable-metadata/1469 "2024-04-15T10:13:16Z")
I want to track the tombstone count in each sstable to determine when to execute compaction. Therefore, I added a new parameter, ‘tombstone\_count,’ to ‘stats\_metadata.’ The newly generated sstable statistics files with t… --- ## [INSERT =\> READ =\> DELETE workflow with single rows](https://forum.scylladb.com/t/insert-read-delete-workflow-with-single-rows/1420)
**Author:** [@Guy](https://forum.scylladb.com/u/Guy)\ **Replies:** 0\ **Last updated:** [March 25, 2024, 6:38am UTC](https://forum.scylladb.com/t/insert-read-delete-workflow-with-single-rows/1420 "2024-03-25T06:38:09Z")
--- ## [Memory issue - deleting big partitions in ScyllaDB with TimeWindowCompactionStrategy](https://forum.scylladb.com/t/memory-issue-deleting-big-partitions-in-scylladb-with-timewindowcompactionstrategy/1395)
**Author:** [@Guy](https://forum.scylladb.com/u/Guy)\ **Replies:** 0\ **Last updated:** [March 19, 2024, 5:59am UTC](https://forum.scylladb.com/t/memory-issue-deleting-big-partitions-in-scylladb-with-timewindowcompactionstrategy/1395 "2024-03-19T05:59:29Z")
--- ## [Cassandra's unchecked\_tombstone\_compaction not recognized](https://forum.scylladb.com/t/cassandras-unchecked-tombstone-compaction-not-recognized/1360)
**Author:** [@hanishi](https://forum.scylladb.com/u/hanishi)\ **Replies:** 4\ **Last updated:** [March 7, 2024, 6:23am UTC](https://forum.scylladb.com/t/cassandras-unchecked-tombstone-compaction-not-recognized/1360 "2024-03-07T06:23:03Z")
I’m engaging with the community to share an experience and seek insights regarding ScyllaDB’s handling of specific Cassandra’s tombstone compaction option, particularly unchecked\_tombstone\_compaction. While integrating … [Next page](https://forum.scylladb.com/tag/compaction/37.md?match_all_tags=true&page=1&tags%5B%5D=compaction)