| = sstablelevelreset |
| |
| 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 |
| http://cassandra.apache.org/doc/latest/operating/compaction.html#leveled-compaction-strategy |
| 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. |
| |
| ref: https://issues.apache.org/jira/browse/CASSANDRA-5271 |
| |
| == Usage |
| |
| 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. |
| |
| Example: |
| |
| .... |
| ColumnFamily not found: keyspace/evenlog. |
| .... |
| |
| == Table has no sstables |
| |
| Example: |
| |
| .... |
| 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. |
| |
| Example: |
| |
| .... |
| 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. |
| |
| Example: |
| |
| .... |
| 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 |
| .... |
