nodetool scrub

Rebuilds SSTables for one or more tables.

Creates a snapshot and then rebuilds SSTables on a node. If possible use nodetool upgradesstables instead of scrub.

Scrub automatically discards broken data and removes any tombstoned rows that have exceeded gc_grace period of the table. If partition key values do not match the column data type, the partition is considered corrupt and the process automatically stops.

Attention: When using LCS, resets all SSTables back to Level 0 and requires recompaction of all SSTables.


install_location/bin/nodetool main_options scrub [(-j <jobs> | --jobs <jobs>)] \
[(-n | --no-validate)][(-ns | --no-snapshot)] \
[ --reinsert-overflowed-ttl ] \
[(-s | --skip-corrupted)] \
[--] [<keyspace> <tables>...]

Connection options

Connection options specify how to connect and authenticate for all nodetool commands:
Short Long Description
-h --host Hostname or IP address.
-p --port Port number.
-pwf --password-file Password file path.
-pw --password Password.
-u --username Username.
-- Separates command parameters from a list of options.
  • If a username and password for RMI authentication are set explicitly in the file for the host, then you must specify credentials.
  • The repair and rebuild commands can affect multiple nodes in the cluster.
  • Most nodetool commands operate on a single node in the cluster if -h is not used to identify one or more other nodes. If the node from which you issue the command is the intended target, you do not need the -h option to identify the target; otherwise, for remote invocation, identify the target node, or nodes, using -h.
nodetool -u username -pw password describering demo_keyspace

  • The file is located in the installation_location/conf directory.

Scrub parameters

Use the following parameters with the scrub command:

-j | --jobs jobs
Number of SSTables to simultaneously scrub. Zero (0) uses all available compaction threads.

Default: 2.

-n | --no-validate
Suppresses validation of columns.

Default: Validate all columns.

-ns --no-snapshot
Suppresses creation of snapshot.

Default: Create a snapshot before rebuilding SSTables.

Rewrites SSTables containing rows with overflowed expiration time with the maximum expiration date of 2038-01-19T03:14:06+00:00 using the original timestamp + 1 (ms).
-s | --skip-corrupted
Forces scrub to skip corrupt partitions and continue. Corrupt partitions have a column value that does not match the column data type. Logs skipped partitions in the system.log.

Default: Stop scrubbing if a corrupted partition is detected.

Note: Skipping corrupted partitions on tables with counter columns results in under-counting.
keyspace_name table_name […]
Identifies the keyspace and targets specific tables using a space separated list.

Default: Include all keyspaces and tables on the node when no arguments are specified.