| = sstablesplit |
| |
| Big sstable files can take up a lot of disk space. The sstablesplit tool |
| can be used to split those large files into smaller files. It can be |
| thought of as a type of anticompaction. |
| |
| ref: https://issues.apache.org/jira/browse/CASSANDRA-4766 |
| |
| Cassandra must be stopped before this tool is executed, or unexpected |
| results will occur. Note: the script does not verify that Cassandra is |
| stopped. |
| |
| == Usage |
| |
| sstablesplit <options> <filename> |
| |
| [cols=",",] |
| |=== |
| |--debug |display stack traces |
| |
| |-h, --help |display this help message |
| |
| |--no-snapshot |don't snapshot the sstables before splitting |
| |
| |-s, --size <size> |maximum size in MB for the output sstables (default: |
| 50) |
| |=== |
| |
| This command should be run with Cassandra stopped. Note: the script does |
| not verify that Cassandra is stopped. |
| |
| == Split a File |
| |
| Split a large sstable into smaller sstables. By default, unless the |
| option --no-snapshot is added, a snapshot will be done of the original |
| sstable and placed in the snapshots folder. |
| |
| Example: |
| |
| .... |
| sstablesplit /var/lib/cassandra/data/keyspace/eventlog-6365332094dd11e88f324f9c503e4753/mc-8-big-Data.db |
| |
| Pre-split sstables snapshotted into snapshot pre-split-1533144514795 |
| .... |
| |
| == Split Multiple Files |
| |
| Wildcards can be used in the filename portion of the command to split |
| multiple files. |
| |
| Example: |
| |
| .... |
| sstablesplit --size 1 /var/lib/cassandra/data/keyspace/eventlog-6365332094dd11e88f324f9c503e4753/mc-1* |
| .... |
| |
| == Attempt to Split a Small File |
| |
| If the file is already smaller than the split size provided, the sstable |
| will not be split. |
| |
| Example: |
| |
| .... |
| sstablesplit /var/lib/cassandra/data/keyspace/eventlog-6365332094dd11e88f324f9c503e4753/mc-8-big-Data.db |
| Skipping /var/lib/cassandra/data/keyspace/eventlog-6365332094dd11e88f324f9c503e4753/mc-8-big-Data.db: it's size (1.442 MB) is less than the split size (50 MB) |
| No sstables needed splitting. |
| .... |
| |
| == Split a File into Specified Size |
| |
| The default size used for splitting is 50MB. Specify another size with |
| the --size option. The size is in megabytes (MB). Specify only the |
| number, not the units. For example --size 50 is correct, but --size 50MB |
| is not. |
| |
| Example: |
| |
| .... |
| sstablesplit --size 1 /var/lib/cassandra/data/keyspace/eventlog-6365332094dd11e88f324f9c503e4753/mc-9-big-Data.db |
| Pre-split sstables snapshotted into snapshot pre-split-1533144996008 |
| .... |
| |
| == Split Without Snapshot |
| |
| By default, sstablesplit will create a snapshot before splitting. If a |
| snapshot is not needed, use the --no-snapshot option to skip it. |
| |
| Example: |
| |
| .... |
| sstablesplit --size 1 --no-snapshot /var/lib/cassandra/data/keyspace/eventlog-6365332094dd11e88f324f9c503e4753/mc-11-big-Data.db |
| .... |
| |
| Note: There is no output, but you can see the results in your file |
| system. |
