Configure the security keyspaces replication factors
Configure the replication factors appropriately for HCD security in production environments.
Change the replication class to NetworkTopologyStrategy
and set the replication factor (RF) between 3
to 5
for the following security keyspaces:
-
system_auth
-
hcd_security
Default replication factors
The default replication factor for the system_auth
and hcd_security
keyspaces is 1
.
To avoid data loss, each of these must be updated in production environments.
DataStax recommends changing the replication factor before enabling authentication.
HCD uses a consistency level of LOCAL_ONE
for all security keyspaces queries, except when using the cassandra
role.
For the cassandra
role, HCD uses the consistency level QUORUM
.
Use the cassandra
role only to login and create your own full access account;
then drop the cassandra
role.
Increase the RF before enabling HCD authentication.
The default login account, |
Recommended replication factors
Determine the appropriate RF based on your failure tolerance and the size of your deployment.
-
system_auth
: Required for each log in and for every action that affects a database object. Once a user logs in, their credentials, roles, and permissions are cached for a period set in the cassandra.yaml. For more information, see Security properties, which contains LDAP, native authentication, and authorization related data. When the keyspace is unavailable, logins and actions may fail. When located on a node in another datacenter, this scenario may cause delays that also can lead to failures. The keyspace tables are relatively small.DataStax recommends using a replication factor of
3
,4
, or5
per datacenter.HCD caches security data. For information about adjusting the cache interval, see Security properties.
Procedure
-
To change the replication factors (RF) of the security keyspaces:
-
Change the
system_auth
keyspace RF:ALTER KEYSPACE system_auth WITH REPLICATION= {'class' : 'NetworkTopologyStrategy', 'data_center_name' : <N>, 'data_center_name' : <N>};
Every time you add or remove a datacenter, you must manually reconfigure the
system_auth
keyspace. -
Change the
hcd_security
keyspace RF:ALTER KEYSPACE hcd_security WITH REPLICATION= {'class' : 'NetworkTopologyStrategy', 'data_center_name' : <N>, 'data_center_name' : <N>};
Every time you add or remove a datacenter, you must manually reconfigure the
hcd_security
keyspace. If HCD or Spark security options are enabled on the cluster, you must also increase the replication factor for thehcd_leases
keyspace across all logical datacenters. -
Run the nodetool repair on the security keyspaces.
nodetool repair --full system_auth nodetool repair --full hcd_security
After changing the replication strategy, you must run
nodetool repair
with its--full option
.