Configuration

• Key Value Service Configurations
• External Timelock Service Configurations
• Cassandra Configuration
• Multinode Cassandra HA Guarantees
• Enabling Cassandra Tracing
• Leader Configuration
• Logging Configuration
• Timestamp Client Options
• Internal Schema Configuration

AtlasDB Configuration

AtlasDB uses a YAML based configuration file with a default root configuration block denoted by atlasdb.

The primary config block for your AtlasDB client will be keyValueServiceConfig. This is where all of the KVS specific parameters will go. Please see Key Value Service Configurations for details on specific KVS configurations.

In addition to the keyValueServiceConfig, you must specify a configuration for the timestamp and lock services. If you are using an embedded timestamp and lock service, see the Leader Configuration documentation. If you are using the external Timelock service, then see the Timelock client configuration.

Furthermore, you may configure a namespace for your AtlasDB client. If using TimeLock, this will be the name of your TimeLock client; if using Cassandra, this will also be the name of your keyspace. If this is not configured, we will read the client from the TimeLock client block, and the keyspace directly from the Cassandra KVS config block respectively. Note that AtlasDB will fail to start if any pair of the following are not equal: the namespace, the Cassandra keyspace or the TimeLock client. Previously, users’ Cassandra keyspaces and TimeLock clients were configured independently; this could lead to data corruption if one misconfigured one of the parameters.

For a full list of the configurations available at the atlasdb root level, see AtlasDbConfig.java.

A second root configuration block can be specified for live-reloadable configs. Parameters related to Sweep can be specified there and will be reloaded in each sweep run. Parameters concerning batching of timestamp requests may also be configured; see Timestamp Client for more details. Some of the KeyValueService parameters can be live-reloadable if specified in this block under the keyValueService config. For a full list of the configurations available at this block, see AtlasDbRuntimeConfig.java.

Example Configuration

atlasdb:
  namespace: yourapp

  keyValueService:
    type: cassandra
    servers:
      - cassandra-1:9160
      - cassandra-2:9160
      - cassandra-3:9160
    poolSize: 30
    credentials:
      username: cassandra
      password: cassandra
    sslConfiguration:
      trustStorePath: var/security/truststore.jks
    replicationFactor: 3
    mutationBatchCount: 10000
    mutationBatchSizeBytes: 10000000
    fetchBatchCount: 1000
    autoRefreshNodes: false

  leader:
    # This should be at least half the number of nodes in your cluster
    quorumSize: 2
    learnerLogDir: var/data/paxosLogs
    acceptorLogDir: var/data/paxosLogs
    localServer: https://host1:3828
    lockCreator: https://host1:3828
    # This should be the same for every node
    leaders:
      - https://host1:3828 # If ssl is not enabled, then the hosts must be specified as http
      - https://host2:3828
      - https://host3:3828
    sslConfiguration:
      trustStorePath: var/security/truststore.jks

atlasdb-runtime:
  timestampClient:
    enableTimestampBatching: true
  keyValueService:
    type: cassandra
    sweepReadThreads: 16
  internalSchema:
    targetTransactionsSchemaVersion: 3