nodetool repair 

Repairs one or more tables.

Repairs one or more tables.

Important: DataStax recommends stopping repair operations during topology changes; the Repair Service does this automatically. Repairs running during a topology change are likely to error when it involves moving ranges.

Synopsis 

$  nodetool [(-h <host> | --host <host>)] [(-p <port> | --port <port>)]
     [(-pw password | --password password)]
     [(-pwf passwordFilePath | --password-file passwordFilePath)]
     [(-u username | --username username)] repair
     [(-dc specific_dc | --in-dc specific_dc)...]
     [(-dcpar | --dc-parallel)] [(-et end_token | --end-token end_token)]
     [(-full | --full)]
     [(-hosts specific_host | --in-hosts specific_host)...]
     [(-j job_threads | --job-threads job_threads)]
     [(-local | --in-local-dc)] [(-pr | --partitioner-range)]
     [(-seq | --sequential)]
     [(-st start_token | --start-token start_token)] [(-tr | --trace)]
     [--] [keyspace tables...]
Options
Short Long Description
-h --host Hostname or IP address.
-p --port Port number.
-pwf --password-file Password file path.
-pw --password Password.
-u --username Remote JMX agent username.
-dc specific_dc --in-dc specific_dc Repair to nodes in the named datacenter (specific_dc).
-dcpar --dc-parallel Repair datacenters in parallel, one node per datacenter at a time.
-et end_token --end-token end_token Token UUID. Repair a range of nodes starting with the first token (see -st) and ending with this token (end_token). Use -hosts to specify neighbor nodes.
-full --full Do a full repair.
-h host_name --host host_name Node host name or IP address.
-hosts specific_host --in-hosts specific_host Repair specific hosts.
-j job_threads --job-threads job_threads Number of threads (job_threads) to run repair jobs. Usually the number of tables to repair concurrently. Be aware that increasing this setting puts more load on repairing nodes. (Default: 1, maximum: 4)
-local --in-local-dc Use to only repair nodes in the same datacenter.
-pr --partitioner-range Run a repair on the partition ranges that are primary on a replica.
-seq start_token --sequential start_token Run a sequential repair.
-st start_token --start-token start_token Specify the token (start_token) at which the repair range starts.
-tr --trace Trace the repair. Traces are logged to system_traces.events.
keyspace Name of keyspace.
tables One or more table names, separated by a space.
-- Separates an option from an argument that could be mistaken for a option.

Description 

Performing an anti-entropy node repair on a regular basis is important, especially in an environment that deletes data frequently. The repair command repairs one or more nodes in a cluster, and provides options for restricting repair to a set of nodes. Anti-entropy node repair performs the following tasks:
  • Ensures that all data on a replica is consistent.
  • Repairs inconsistencies on a node that has been down.

Incremental repair is the default for Cassandra 2.2 and later, and full repair is the default in Cassandra 2.1 and earlier. In Cassandra 2.2 and later, when a full repair is run, SSTables are marked as repaired and anti-compacted. Parallel repair is the default for Cassandra 2.2 and later, and sequential repair is the default in Cassandra 2.1 and earlier.

Using options 

You can use options to do these other types of repair:
  • Sequential or Parallel
  • Full or incremental

Use the -hosts option to list the good nodes to use for repairing the bad nodes. Use -h to name the bad nodes.

Use the -full option for a full repair if required. By default, an incremental repair eliminates the need for constant Merkle tree construction by persisting already repaired data and calculating only the Merkle trees for SSTables that have not been repaired. The repair process is likely more performant than the other types of repair even as datasets grow, assuming you run repairs frequently. Before doing an incremental repair for the first time, perform migration steps first if necessary for tables created before Cassandra 2.2.

Use the -dcpar option to repair data centers in parallel. Unlike sequential repair, parallel repair constructs the Merkle tables for all data centers at the same time. Therefore, no snapshots are required (or generated). Use parallel repair to complete the repair quickly or when you have operational downtime that allows the resources to be completely consumed during the repair.

Performing partitioner range repairs by using the -pr option is generally considered a good choice for doing manual repairs. However, do not use this option with incremental repairs (default for Cassandra 3.0 and later).

Example 

All nodetool repair arguments are optional.

To do a sequential repair of all keyspaces on the current node:
$ nodetool repair -seq
To do a partitioner range repair of the bad partition on current node using the good partitions on 10.2.2.20 or 10.2.2.21:
$ nodetool repair -pr -hosts 10.2.2.20 10.2.2.21
For a start-point-to-end-point repair of all nodes between two nodes on the ring:
$ nodetool -st a9fa31c7-f3c0-44d1-b8e7-a26228867840c -et f5bb146c-db51-475ca44f-9facf2f1ad6e 
To restrict the repair to the local data center, use the -dc option followed by the name of the data center. Issue the command from a node in the data center you want to repair. Issuing the command from a data center other than the named one returns an error. Do not use -pr with this option to repair only a local data center.
$ nodetool repair -dc DC1
Results in output:
[2014-07-24 21:59:55,326] Nothing to repair for keyspace 'system'
[2014-07-24 21:59:55,617] Starting repair command #2, repairing 490 ranges 
  for keyspace system_traces (seq=true, full=true)
[2014-07-24 22:23:14,299] Repair session 323b9490-137e-11e4-88e3-c972e09793ca 
  for range (820981369067266915,822627736366088177] finished
[2014-07-24 22:23:14,320] Repair session 38496a61-137e-11e4-88e3-c972e09793ca 
  for range (2506042417712465541,2515941262699962473] finished
. . .
And an inspection of the system.log shows repair taking place only on IP addresses in DC1.
. . .
INFO  [AntiEntropyStage:1] 2014-07-24 22:23:10,708 RepairSession.java:171 
  - [repair #16499ef0-1381-11e4-88e3-c972e09793ca] Received merkle tree 
  for sessions from /192.168.2.101
INFO  [RepairJobTask:1] 2014-07-24 22:23:10,740 RepairJob.java:145 
  - [repair #16499ef0-1381-11e4-88e3-c972e09793ca] requesting merkle trees 
  for events (to [/192.168.2.103, /192.168.2.101])
. . .