nodetool setcachecapacity

Set global key and row cache capacities in megabytes.

cassandra.yaml

The location of the cassandra.yaml file depends on the type of installation:
Package installations /etc/dse/cassandra/cassandra.yaml
Tarball installations installation_location/resources/cassandra/conf/cassandra.yaml

Sets global key and row cache capacities in megabytes. A value of 0 means that the cache is disabled.

Tip: Overrides the configured value of the row_cache_size_in_mb parameter in cassandra.yaml.
Tip: To change the current setting, use nodetool getcachecapacity.

Synopsis

nodetool [connection_options] setcachecapacity
[--] key-cache-capacity row-cache-capacity counter-cache-capacity
Table 1. Legend
Syntax conventions Description
UPPERCASE Literal keyword.
Lowercase Not literal.
Italics Variable value. Replace with a valid option or user-defined value.
[ ] Optional. Square brackets ( [ ] ) surround optional command arguments. Do not type the square brackets.
( ) Group. Parentheses ( ( ) ) identify a group to choose from. Do not type the parentheses.
| Or. A vertical bar ( | ) separates alternative elements. Type any one of the elements. Do not type the vertical bar.
... Repeatable. An ellipsis ( ... ) indicates that you can repeat the syntax element as often as required.
'Literal string' Single quotation ( ' ) marks must surround literal strings in CQL statements. Use single quotation marks to preserve upper case.
{ key:value } Map collection. Braces ( { } ) enclose map collections or key value pairs. A colon separates the key and the value.
<datatype1,datatype2> Set, list, map, or tuple. Angle brackets ( < > ) enclose data types in a set, list, map, or tuple. Separate the data types with a comma.
cql_statement; End CQL statement. A semicolon ( ; ) terminates all CQL statements.
[ -- ] Separate the command line options from the command arguments with two hyphens ( -- ). This syntax is useful when arguments might be mistaken for command line options.
' <schema> ... </schema> ' Search CQL only: Single quotation marks ( ' ) surround an entire XML schema declaration.
@xml_entity='xml_entity_type' Search CQL only: Identify the entity and literal value to overwrite the XML element in the schema and solrconfig files.

Definition

The short form and long form parameters 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
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
The filepath to the file that stores JMX authentication credentials.
-u, --username jmx_username
The username for authenticating with secure JMX.

Command arguments

counter-cache-capacity
Corresponds to the counter_cache_size_in_mb in cassandra.yaml.
  • number - the number of keys saved by each cache
  • 0 - disable counter caching
Default: Smaller of minimum of 2.5% of heap or 50 MB.
key-cache-capacity
Key cache capacity in MB units.
  • number - the number of MB saved by each cache
  • 0 - disable caching
row-cache-capacity
Row cache capacity in MB units. Corresponds to the row_cache_size_in_mb parameter in cassandra.yaml.
  • number - the number of MB saved by each cache
  • 0 - disable caching
Default: 0 (disabled).

Example

Set the global key to 200 MB, row cache to 50 MB, and counter cache to 25 MB capacities

nodetool setcachecapacity 200 0 25
Ensure capacities were updated.
nodetool getcachecapacity
Results:
Key cache capacity: 200 MB
Row cache capacity: 0 MB
Counter cache capacity: 25 MB