nodetool compact
Forces a major compaction on one or more tables or user-defined compaction on given SSTables.
Major compactions may behave differently depending which compaction strategy is used for the affected tables:
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SizeTieredCompactionStrategy (STCS)
: The default compaction strategy. This strategy triggers a minor compaction when there are a number of similar sized SSTables on disk as configured by the table subproperty,min_threshold
. A minor compaction does not involve all the tables in a keyspace. Also see STCS compaction subproperties. -
DateTieredCompactionStrategy (DTCS)
(deprecated). -
TimeWindowCompactionStrategy (TWCS)
: This strategy is an alternative for time series data. TWCS compacts SSTables using a series of time windows. While with a time window, TWCS compacts all SSTables flushed from memory into larger SSTables using STCS. At the end of the time window, all of these SSTables are compacted into a single SSTable. Then the next time window starts and the process repeats. The duration of the time window is the only setting required. See TWCS compaction subproperties. For more information about TWCS, see How is data maintained?. -
LeveledCompactionStrategy (LCS)
: The leveled compaction strategy creates SSTables of a fixed, relatively small size (160 MB by default) that are grouped into levels. Within each level, SSTables are guaranteed to be non-overlapping. Each level (L0, L1, L2 and so on) is 10 times as large as the previous. Disk I/O is more uniform and predictable on higher than on lower levels as SSTables are continuously being compacted into progressively larger levels. At each level, row keys are merged into non-overlapping SSTables in the next level. This process can improve performance for reads, because the database can determine which SSTables in each level to check for the existence of row key data. This compaction strategy is modeled after Google’s LevelDB implementation. Also see LCS compaction subproperties.
A major compaction incurs considerably more disk I/O than minor compactions. |
Synopsis
nodetool [<connection_options>] compact
[-et <end_token>] [-s] [-st <start_token>] [--user-defined]
[--] [<keyspace> <tables> [<tables> ...] | <sstable_name> ...]
Syntax conventions | Description |
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UPPERCASE |
Literal keyword. |
Lowercase |
Not literal. |
<`Italics>` |
Variable value. Replace with a valid option or user-defined value. |
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Optional.
Square brackets ( |
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Group.
Parentheses ( |
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Or.
A vertical bar ( |
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Repeatable.
An ellipsis ( |
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Single quotation ( |
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Map collection.
Braces ( |
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Set, list, map, or tuple.
Angle brackets ( |
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End CQL statement.
A semicolon ( |
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Separate the command line options from the command arguments with two hyphens ( |
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Search CQL only: Single quotation marks ( |
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Search CQL only: Identify the entity and literal value to overwrite the XML element in the schema and solrconfig files. |
Definition
The short- and long-form options are comma-separated.
Connection options
- -h, --host hostname
-
The hostname or IP address of a remote node or nodes. When omitted, the default is the local machine.
- -p, --port jmx_port
-
The JMX port number.
- -pw, --password jmxpassword
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The JMX password for authenticating with secure JMX. If a password is not provided, you are prompted to enter one.
- -pwf, --password-file jmx_password_filepath
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The filepath to the file that stores JMX authentication credentials.
- -u, --username jmx_username
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The username for authenticating with secure JMX.
Command arguments
--
-
Separates an option from an argument that could be mistaken for an option.
- -et, --end-token end_token
-
The token at which the range ends. Requires start token (-st).
- keyspace_name
-
The keyspace name.
- -s, --split-output
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Do not create a single large file. Split output when using SizeTieredCompactionStrategy (STCS) to files that are 50%-25%-12.5% and so on of the total size. Ignored for DTCS.
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- sstable_name
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The name of the SSTable file. Specify <sstable_name> or <sstable_directory>.
- -st, --start-token start_token
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The token at which the range starts. Requires end token (-et).
- table_name
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The table name.
- --user-defined
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Submits listed files for user-defined compaction.