Cassandra Documentation



If LeveledCompactionStrategy is set, this script can be used to reset level to 0 on a given set of sstables. This is useful if you want to, for example, change the minimum sstable size, and therefore restart the compaction process using this new configuration.

See for information on how levels are used in this compaction strategy.

Cassandra must be stopped before this tool is executed, or unexpected results will occur. Note: the script does not verify that Cassandra is stopped.


sstablelevelreset --really-reset <keyspace> <table>

The really-reset flag is required, to ensure this intrusive command is not run accidentally.

Table not found

If the keyspace and/or table is not in the schema (e.g., if you misspelled the table name), the script will return an error.


ColumnFamily not found: keyspace/evenlog.

Table has no sstables


Found no sstables, did you give the correct keyspace/table?

Table already at level 0

The script will not set the level if it is already set to 0.


Skipped /var/lib/cassandra/data/keyspace/eventlog-65c429e08c5a11e8939edf4f403979ef/mc-1-big-Data.db since it is already on level 0

Table levels reduced to 0

If the level is not already 0, then this will reset it to 0.


sstablemetadata /var/lib/cassandra/data/keyspace/eventlog-6365332094dd11e88f324f9c503e4753/mc-8-big-Data.db | grep -i level
SSTable Level: 1

sstablelevelreset --really-reset keyspace eventlog
Changing level from 1 to 0 on /var/lib/cassandra/data/keyspace/eventlog-6365332094dd11e88f324f9c503e4753/mc-8-big-Data.db

sstablemetadata /var/lib/cassandra/data/keyspace/eventlog-6365332094dd11e88f324f9c503e4753/mc-8-big-Data.db | grep -i level
SSTable Level: 0