Cassandra Connection Parameters

These parameters control connections to the Cassandra database using the Thrift or CQL APIs:

dbhost: 'localhost'

This parameter configures the host name(s) or address(es) of the Cassandra node(s) that the Doradus server connect to. Static IP addresses are preferred over host names. If a comma-separated list of hosts is provided, Doradus will connect to each one in round-robin fashion, allowing load balancing and failover.

dbport: 9160

This is the Cassandra Thrift or CQL API port number. Change this value if Cassandra’s port is using something other than 9160. (Cassandra should use the same port on all nodes.)

jmxport: 7199

Change this value if Cassandra’s JMX port is using something other than 7199. (Cassandra should use the same port on all nodes.)

db_timeout_millis: 60000

This is the socket-level Cassandra database connection timeout in milliseconds. It is applicable to both the Thrift and CQL APIs. This time is used both when connecting to Cassandra and when performing read/write operations. If a connect, read, or write request is not received within this time, the connection is closed and a retry is initiated. Note, however, that Cassandra has its own RPC timeout value, which defaults to 10 seconds. This means that read and write operations will typically based on Cassandra’s value and not this one.

db_connect_retry_wait_millis: 30000

This is the Cassandra database (Thrift) initial connection retry wait in milliseconds. It is applicable to both the Thrift and CQL APIs. If an initial connection to Cassandra times-out (see db_timeout_millis above), Doradus waits this amount of time before trying again. Doradus keeps retrying indefinitely under the assumption that Cassandra may take a while to start.

max_commit_attempts: 10

This is the maximum number of times Doradus will attempt to perform a Cassandra update operation before aborting the operation. (See also retry_wait_millis).

max_read_attempts: 3

This is the maximum number of times Doradus will attempt to perform a read operation before aborting the operation. (See also retry_wait_millis).

max_reconnect_attempts: 3

This is the maximum number of times Doradus will attempt to reconnect to Cassandra after a failure. A reconnect is performed if a read or update call fails. (See also retry_wait_millis).

retry_wait_millis: 5000

This is the time in milliseconds that Doradus waits after a failed update, read, or reconnect request call to Cassandra. This time is multiplied by the attempt number, which means Doradus waits a little longer after each successive failed call. (See also max_commit_attempts, max_read_attempts, and max_reconnect_attempts.)

use_cql: false

By default, Doradus uses the Thrift API to communicate with Cassandra. When this option is set to true, it uses the CQL API instead. CQL must be enabled in each Cassandra instance that Doradus connects via the cassandra.yaml file option start_native_transport: true. Additionally, the doradus.yaml file option dbport must be set to the CQL API’s port (the default is 9042).

dbtls: false

Set to true to use TLS/SSL for connections to Cassandra. This option works for both CQL and Thrift. When dbtls is enabled, the options keystore and keystorepassword are used for certificate information.

dbtls_cipher_suites: [TLS_RSA_WITH_AES_128_CBC_SHA]

Set to a list of one or more cipher suites to be used with SSL/TLS to Cassandra. This option is only meaningful if dbtls is set to true. Cassandra must be configured to allow at least one of the same cipher algorithms in order to establish a successful connection. The list can be comma-separated on a single line within square brackets (e.g., [X, Y, Z]), or each cipher suite can be listed on its own line, indented and prefixed with a "-". The cipher suite TLS_RSA_WITH_AES_128_CBC_SHA is generally always allowed by Cassandra.

dbuser: cassandra

dbpassword: cassandra

If authentication/authorization is configured for Cassandra, these parameters must be set to a super user that Doradus can use. When Cassandra's authenticator is set to PasswordAuthorizer, it initially creates the super id/password cassandra/cassandra. A better password and/or a different super user should be created for Doradus. Remember that these values can be passed-in dynamically as run-time arguments. The dbuser and dbpassword parameters can be used for both the Thrift and CQL APIs and for both single- and multi-tenant operation.