Establishing a Connection
You can create and manage connections with the Data Explorer and the FireDAC Connection Editor wizards. See Connection Definitions for more information on creating connections from code and creating persistent, private, or temporary connections.
Connecting to Cassandra
You can connect directly to Cassandra instances, as well as Cosmos DB and DataStax Astra DB via their Cassandra APIs.
Cassandra
Set the following to connect to a Cassandra instance:
- Server: Set this to the the host name or IP address of the server hosting the Cassandra database. You can specify the port at the end of this property or in Port.
- Port: Set this to the port on which the Cassandra database is hosted, if you haven't specified the port as part of the Server connection property.
- Database: Set this to the name of the Cassandra keyspace containing your tables.
- ConsistencyLevel: Set this to the number of the replicas that you want to enforce a response from before queries are considered a success.
- User: Set this to the username used to access your Cassandra database.
- Password: Set this to the password used to access your Cassandra database.
Cosmos DB
If you're using Cosmos DB as your Cassandra data store, specify the following values to connect:- Server: Set this to the Host value, the FQDN of the server provisioned for your account. You can specify the port at the end of this property or in Port.
- Port: Set this to the port on which your Cosmos DB instance is hosted, if you haven't specified the port as part of the Server connection property.
- Database: Set this to the database you want to read from and write to.
- ConsistencyLevel: Set this to the number of the replicas that you want to enforce a response from before queries are considered a success.
- User: Set this to your Cosmos DB account name.
- Password: Set this to the account key associated with the Cosmos DB account.
DataStax Astra DB
If you're using Astra DB as your Cassandra data store, specify the following values to connect:
- Server: Set this to the server in your BASE_ADDRESS value. You can also specify the port here or in Port.
- Port: Set this to the port on which your Astra DB instance is hosted, if you haven't specified the port as part of the Server connection property.
- Database: Set this to the database you want to read from and write to.
- ConsistencyLevel: Set this to the number of the replicas that you want to enforce a response from before queries are considered a success.
- User: Set this to your Astra DB username.
- Password: Set this to the password associated with your Astra DB username.
Secure Bundle Connection
You can configure any connection as a secure bundle by setting the following connection properties:- Server: Set this to your server name.
- Port: Set this to 29042.
- User: Set this to the Atra DB user.
- Password: Set this to Astra DB user password.
- SSLClientCert: Set this to the path to the identity.jks file.
- SSLClientCertType: Set this JKSFILE.
- SSLClientCertPassword: Set this to the password for the identity.jks file.
- SSLClientCertSubject: Set this to CERTIFICATE SUBJECT INFORMATION.
- UseSSL: Set this to "true".
See Secure connect bundle contents for a list of files that are included in a secure bundle.
Authenticating to Cassandra
The component supports Basic authentication with login credentials and the additional authentication features of DataStax Enterprise (DSE). The following sections detail connection properties your authentication method may require.You need to set AuthScheme to the value corresponding to the authenticator configured for your system. You specify the authenticator in the authenticator property in the cassandra.yaml file. This file is typically found in /etc/dse/cassandra or through the DSE Unified Authenticator on DSE Cassandra.
Basic
Set AuthScheme to Basic to authenticate with login credentials alone.
In the cassandra.yaml file, set the authenticator property to "PasswordAuthenticator".
DSE
Set the AuthScheme property to DSE to authenticate with login credentials and the DSE Unified Authenticator.
In the file, set the authenticator property to "com.datastax.bdp.cassandra.auth.DseAuthenticator".
Kerberos
Set the following to authenticating using Kerberos:
- AuthScheme: Set this to KERBEROS.
- KerberosKDC: Set this to the Kerberos Key Distribution Center (KDC) service used to authenticate the user.
- KerberosRealm: Set this to the Kerberos Realm used to authenticate the user.
- KerberosSPN: Set this to the service principal name (SPN) for the Kerberos Domain Controller.
- In the cassandra.yaml file, set the authenticator property to "com.datastax.bdp.cassandra.auth.DseAuthenticator".
- Modify the authentication_options section in the dse.yaml file, specifying the default_schema and other_schemas properties as "kerberos".
- Modify the kerberos_options section in the dse.yaml file, specifying the keytab, service_principle, http_principle and qop properties.
Please see Using Kerberos for more details on how to set connection properties in order to connect to Kerberos.
LDAP
Set the following to authenticate:
- AuthScheme: Set this to LDAP to authenticate an LDAP user.
- LDAPServer: Set this to the host name or IP address of the LDAP server.
- LDAPPassword: The password of the default LDAP user.
- In the cassandra.yaml file, set the authenticator property to "com.datastax.bdp.cassandra.auth.DseAuthenticator".
- Modify the authentication_options section in the dse.yaml file, specifying the default_schema and other_schemas properties as "ldap".
- Modify the ldap_options section in the dse.yaml file, specifying the server_host, server_port, search_dn, search_password, user_search_base, and user_search_filter properties.
Securing Cassandra Connections
You can set UseSSL to negotiate SSL/TLS encryption when you connect. By default, the component attempts to negotiate SSL/TLS by checking the server's certificate against the system's trusted certificate store. To specify another certificate, see the SSLServerCert property for the available formats.
Using the FireDAC Connection Editor
Complete the following steps to use the FireDAC Connection Editor to assign a Cassandra connection to a TFDConnection object:
- Open a project and drop a TFDPhysCDataCassandraDriverLink from the Tool Palette onto the Form Designer.
- Drop a TFDConnection object onto the Form Designer.
- Double-click the TFDConnection and select CDataCassandra in the Driver Id menu.
- Define the necessary connection properties.
- To execute ad-hoc SQL statements based on this connection, enter SQL commands on the SQL Script tab.
- In the Form Designer, select the TFDConnection object and set the Connected property to true.
Using the Data Explorer
Complete the following steps to use the Data Explorer to define persistent connections that can be shared across applications and projects:
- Click View > Tool Windows > Data Explorer in RAD Studio and expand the FireDAC node.
- Right-click the CData Cassandra Data Source node and click Add New Connection.
- Enter a name for the connection. The FireDAC Connection Editor opens.
Working with Persistent Connections
The connections you define in the Data Explorer can be assigned to a TFDConnection object by specifying the connection name in the TFDConnection object's ConnectionDefName property.
Browsing Data and Metadata
The Data Explorer also provides options for browsing Cassandra objects at design time:
- Expand the CData Cassandra Data Source node in the Data Explorer to view the defined connections.
- Expand a connection node to find the database objects available for a connection.
- Drill down to a database object to find metadata such as primary keys.
- To display data, double-click a table or view or right-click and click View.