Configuring cache settings

Change the amount of time and refresh rate for the role and permissions cache.

By default, DataStax Enterprise (DSE) caches the login user's roles and corresponding permissions. Caching allows multiple connection requests to occur within the specified period without repeating the entire authorization process (querying the system_auth tables) for every action.

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

Security-related cache settings

Adjust settings in the cassandra.yaml file:

roles_validity_in_ms
Validity period for roles cache in milliseconds. Determines how long to cache the list of roles assigned to the user; users may have several roles, either through direct assignment or inheritance (a role that has been granted to another role). Adjust this setting based on the complexity of your role hierarchy, tolerance for role changes, the number of nodes in your environment, and activity level of the cluster.
Fetching permissions can be an expensive operation, so this setting allows flexibility. Granted roles are cached for authenticated sessions in AuthenticatedUser. After the specified time elapses, role validity is rechecked. Disabled automatically when internal authentication is not enabled when using DseAuthenticator.
  • 0 - disable role caching
  • milliseconds - how long to cache the list of roles assigned to the user

Default: 120000 (2 minutes)

roles_update_interval_in_ms
Refresh interval for roles cache. After this interval, cache entries become eligible for refresh. On next access, the database schedules an async reload, and returns the old value until the reload completes. If roles_validity_in_ms is non-zero, then this value must also be non-zero. When not set, the default is the same value as roles_validity_in_ms.

Default: commented out (120000) 

permissions_validity_in_ms
How long permissions in cache remain valid to manage performance impact of permissions queries. Fetching permissions can be resource intensive. Set the cache validity period to your security tolerances. The cache is used for the standard authentication and the row-level access control (RLAC) cache. The cache is quite effective at small durations.
  • 0 - disable permissions cache
  • milliseconds - time, in milliseconds
CAUTION: REVOKE does not automatically invalidate cached permissions. Permissions are invalidated the next time they are refreshed.

Default: 120000 (2 minutes)

permissions_update_interval_in_ms
Sets refresh interval for the standard authentication cache and the row-level access control (RLAC) cache. After this interval, cache entries become eligible for refresh. On next access, the database schedules an async reload and returns the old value until the reload completes. If permissions_validity_in_ms is non-zero, the value for roles_update_interval_in_ms must also be non-zero. When not set, the default is the same value as permissions_validity_in_ms.

Default: commented out (2000) 

permissions_cache_max_entries
The maximum number of entries that are held by the standard authentication cache and row-level access control (RLAC) cache. With the default value of 1000, the RLAC permissions cache can have up to 1000 entries in it, and the standard authentication cache can have up to 1000 entries. This single option applies to both caches. To size the permissions cache for use with Setting up Row Level Access Control (RLAC), use this formula:
numRlacUsers * numRlacTables + 100
If this option is not present in cassandra.yaml, manually enter it to use a value other than 1000. See Enabling DSE Unified Authentication.

Default: not set (1000) 

Disabling Authentication and Authorization caching

To disable configuration of authorization caches (for roles and permissions), uncomment the following line in the jvm.options file:

-Dcassandra.disable_auth_caches_remote_configuration=true

After setting this option, cache options can be set only in the cassandra.yaml file. To make the new setting take effect, restart Cassandra.