The dsetool

Use the dsetool utility for Cassandra File System (CFS) and Hadoop-related tasks, such as managing the job tracker, checking the CFS, and listing node subranges of data in a keyspace.

You can use the dsetool utility for Cassandra File System (CFS) and Hadoop-related tasks, such as managing the job tracker, checking the CFS, and listing node subranges of data in a keyspace. Only JMX ( java management extensions) provides dsetool password authentication. If JMX passwords are enabled, users then need to use the passwords to use the dsetool utility.

Usage: dsetool [-h|--host=hostname] [-p|--port=#] [-j|--jmxport=#] command args

This table describes the dsetool arguments:

Short form	Long form	Description
`-a`	`--jmx-username arg`	User name for authenticating with secure JMX.
`-b`	`--jmx-password arg`	Password for authenticating with secure JMX.
`-h`	`--host arg`	Node hostname or IP address.
`-j`	`--jmxport arg`	Remote JMX agent port numbe.r
`-u`	`--use_hadoop_config`	Get cassandra host from Hadoop configuration files.

The dsetool commands are:

checkcfs: Check a single CFS file or the whole CFS.

createsystemkey encryption option [encryption option ... ] [system key name]: Creates the system key for transparent data encrpytion. DataStax 4.5.2 and later.

inmemorystatus keyspace table: Provides the memory size, capacity, and percentage used by the table. The unit of measurement is MB. Bytes are truncated.

listjt: List all job tracker nodes grouped by DC local to them.

list_subranges keyspace cf-name keys_per_range start_token, end_token: Divide a token range for a given keyspace/table into a number of smaller subranges of approximately keys_per_range. To be useful, the specified range should be contained by the target node's primary range.

jobtracker: Return the job tracker hostname and port, JT local to the DC from which you are running the command.

movejt: Move the job tracker and notify the task tracker nodes.

partitioner: Return the fully qualified classname of the IPartitioner in use by the cluster

repaircfs: Repair the CFS from orphan blocks.

rebuild_indexes keyspace table-name idx1,idx2,...: Rebuild specified secondary indexes for given keyspace/table. Use only keyspace/table-name to re-build all indexes.

ring: List the nodes in the ring including their node type.

sparkmaster: Returns address of Spark master running on the same node as the job tracker.

sparkmaster cleanup [dc_name]: Removes state information about the Spark Master that DataStax Enterprise saves in CFS for high availability of the master.

sparkworker restart: Manually restarts the Spark Worker on the selected node, without restarting the node.

status: Same as the ring command.

Examples of using dsetool commands for managing the job tracker are presented in Managing the job tracker using dsetool commands.

Checking the CFS using dsetool

Use the dsetool checkcfs command to scan the Cassandra File System (CFS) for corrupted files. For example:

dsetool checkcfs cfs:///

Use the dsetool to get details about a particular file that has been corrupted. For example:

dsetool checkcfs /tmp/myhadoop/mapred/system/jobtracker.info

Listing sub-ranges using dsetool

The dsetool command syntax for listing subranges of data in a keyspace is:

dsetool [-h ] [hostname ] list_subranges keyspace table rows per subrange start token end token

rows per subrange is the approximate number of rows per subrange.
start partition range is the start range of the node.
end partition range is the end range of the node.

Note: You run nodetool repair on a single node using the output of list_subranges. The output must be partition ranges used on that node.

Example

dsetool list_subranges Keyspace1 Standard1 10000 113427455640312821154458202477256070485 0

Output

The output lists the subranges to use as input to the nodetool repair command. For example:

Start Token                             End Token                               Estimated Size
------------------------------------------------------------------------------------------------
113427455640312821154458202477256070485 132425442795624521227151664615147681247 11264
132425442795624521227151664615147681247 151409576048389227347257997936583470460 11136
151409576048389227347257997936583470460 0                                       11264

Nodetool repair command options

You need to use the nodetool utility when working with sub-ranges. The start partition range (-st) and end partition range (-et) options specify the portion of the node needing repair. You get values for the start and end tokens from the output of dsetool list_subranges command. The new nodetool repair syntax for using these options is:

nodetool repair keyspace table -st start token  -et end token

Example

nodetool repair Keyspace1 Standard1 -st 113427455640312821154458202477256070485 -et 132425442795624521227151664615147681247 
nodetool repair Keyspace1 Standard1 -st 132425442795624521227151664615147681247 -et 151409576048389227347257997936583470460
nodetool repair Keyspace1 Standard1 -st 151409576048389227347257997936583470460 -et 0

These commands begins an anti-entropy node repair from the start partition range to the end partition range.

Using dsetool with Kerberos

To use dsetool with Kerberos, use one of these methods:

Using the ~/.dserc file
Create or edit the ~/.dserc file in your DataStax Enterprise home directory and add the following entries:
```
sasl_protocol=service_name
login_config=path_to_login_config
```
Command line options
Specify the service name and JAAS configuration file on the command line:
```
-Ddse.sasl.protocol=service_name
-Djava.security.auth.login.config=path_to_login_config
```
where:
- service_name is the service name component of the service_principal that is defined in the dse.yaml file
- path_to_login_config is the JAAS configuration file with the following options declared in it:
```
DseClient {
            com.sun.security.auth.module.Krb5LoginModule required
            useTicketCache=true
            renewTGT=true;
        };
```