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Dremio Services Configuration

The dremio.conf file is used to configure Dremio services. By default, dremio.conf is located under the /etc/dremio/ directory, however, if the file is absent from the configuration directory, Dremio uses a default configuration and starts up. The dremio.conf file uses the HOCON syntax. Drmeio provides a template of dremio.conf to assist in creating your configuration.

Template dremio.conf configuration file

paths: {

  # the local path for dremio to store data.
  local: ${DREMIO_HOME}"/data"

  # the distributed path Dremio data including job results, downloads, uploads, etc
  dist: "pdfs://"${paths.local}"/pdfs"

  # location for catalog database (if master node)
  db: ${paths.local}/db,

  spilling: [${paths.local}/spill]

  # storage area for the accelerator cache.
  accelerator: ${paths.dist}/accelerator

  # staging area for json and csv ui downloads
  downloads: ${paths.dist}/downloads

  # stores uploaded data associated with user home directories
  uploads: ${paths.dist}/uploads

  # stores data associated with the job results cache.
  results: ${paths.dist}/results

  # shared scratch space for creation of tables.
  scratch: ${paths.dist}/scratch

}

services: {
  coordinator: {
    enabled: true,

    # Auto-upgrade Dremio at startup if needed
    auto-upgrade: false,

    master: {
      enabled: true,
      # configure an embedded ZooKeeper server on the same node as master
      embedded-zookeeper: {
        enabled: true,
        port: 2181,
        path: ${paths.local}/zk
      }
    },

    web: {
      enabled: true,
      port: 9047,
      ssl: {
        # If SSL for communication path between browsers (or REST clients) and Dremio should be enabled.
        enabled: false,

        # Allow for auto-generated certificates if keyStore option is not set
        # Auto-generated self-signed certificates are considered insecure, and this
        # option should be set to false in production environment
        auto-certificate.enabled: true

        # KeyStore and TrustStore settings default to Java keystore and truststore JVM arguments.
        # If needed to be overridden, then change the below properties

        # KeyStore type
        keyStoreType: ${javax.net.ssl.keyStoreType},

        # Path to KeyStore file
        keyStore: ${javax.net.ssl.keyStore},

        # Password to access the keystore file
        keyStorePassword: ${javax.net.ssl.keyStorePassword},

        # Password to access the key
        keyPassword: ${javax.net.ssl.keyPassword},

        # TrustStore type
        trustStoreType: ${javax.net.ssl.trustStoreType},

        # Path to TrustStore file
        trustStore: ${javax.net.ssl.trustStore},

        # Password to access the truststore file
        trustStorePassword: ${javax.net.ssl.trustStorePassword}
      },
      auth: {
        type: "internal", # Possible values are "internal", "ldap" (includes Microsoft Entra ID)
        # LDAP config file for configuration when auth type is "ldap"
        ldap_config: "ldap.json" # file name provided should be in the classpath.
      }
      tokens: {
        cache: {
          # number of tokens to store locally on this coordinator node
          # (set to 0, if all requests should be made directly to the database of tokens)
          size: 100
          # time (in minutes) after which the token needs to be obtained from the token store
          expiration_minutes: 5
        }
      }
    },

    client-endpoint: {
      port: 31010
    },

    scheduler: {
      threads: 24
    },

    command-pool: {
      enabled: true
      size: 0 # 0 defaults to the machine's number of cores
    }
  },

  executor: {
    enabled: true
  },

  flight: {
      enabled: true,
      port: 32010,
      # Authentication mode for the Arrow FlightServer endpoint.
      # There are two modes:
      #       - legacy.arrow.flight.auth
      #       - arrow.flight.auth2
      # legacy.arrow.flight.auth is backwards compatible and will be deprecated in the future.
      # arrow.flight.auth2 is the new and preferred Arrow Flight authentication method.
      auth.mode: "arrow.flight.auth2"
   }

  fabric: {
    port: 45678,

    memory: {
      reservation: 100M
    }
  },

  conduit: {
    # If set to 0, a port is automatically allocated (typically in ephemeral range). Otherwise, the configured value
    # is used.
    port: 0

    ssl: {
      # If SSL for communication path between Dremio instances should be enabled.
      enabled: ${services.fabric.ssl.enabled},

      # Allow for auto-generated certificates if keyStore option is not set
      # Auto-generated self-signed certificates are considered insecure, and this
      # option should be set to false in production environment
      auto-certificate.enabled: ${services.fabric.ssl.auto-certificate.enabled},

      # KeyStore and TrustStore settings default to Java keystore and truststore JVM arguments.
      # If needed to be overridden, then change the below properties

      # KeyStore type
      keyStoreType: ${services.fabric.ssl.keyStoreType},

      # Path to KeyStore file
      keyStore: ${services.fabric.ssl.keyStore},

      # Password to access the keystore file
      keyStorePassword: ${services.fabric.ssl.keyStorePassword},

      # Password to access the key
      keyPassword: ${services.fabric.ssl.keyPassword},

      # TrustStore type
      trustStoreType: ${services.fabric.ssl.trustStoreType},

      # Path to TrustStore file
      trustStore: ${services.fabric.ssl.trustStore},

      # Password to access the truststore file
      trustStorePassword: ${services.fabric.ssl.trustStorePassword}
    }
  }

  # Set up kerberos credentials in server (applicable for both coordinator and executor)
  kerberos: {
    principal: "",
    keytab.file.path: ""
  }

  web-admin: {
    enabled: true,
    # Port, bound to loopback interface, on which the daemon responds to liveness HTTP requests (0 == auto-allocated)
    port: 0
  }
}

provisioning: {
  yarn: {
    jvmoptions: "",
    # list of jars to be added to the main container classpath
    classpath: []
    app {
      # list of jars to be added to the Dremio application classpath
      classpath: []
      # list of jars to be added to the Dremio application classpath (at the front)
      classpath-prefix: []
    }
    watchdog: {
      # how long to wait for server reply before considering it failed
      poll.timeout: 1000ms
      # interval between two server polls
      poll.interval: 10000ms
      # how many consecutive failed attempts before killing server
      missed.polls.before.kill: 6
      # maximum attempts at killing server
      max.kill.attempts: 10
      # how long before reattempting killing server
      kill.reattempt.interval: 1000ms
    }
  }
}

# the zookeeper quorum for the cluster
zookeeper: "localhost:"${services.coordinator.master.embedded-zookeeper.port}
zk.client.session.timeout: 90000

# These system properties are listed here to allow substitution of system property values for DAC Web SSL properties
# listed in services.web.ssl section. Currently we consider only the system properties listed in this file for
# substitution.
javax.net.ssl {
  keyStoreType: "",
  keyStore: "",
  keyStorePassword: "",
  keyPassword: "",
  trustStoreType: "",
  trustStore:"",
  trustStorePassword: ""
}

registration.publish-host: ""

Configuring Basic Services

The Dremio services property determines whether the node is enabled with the master coordinator, secondary coordinator, or executor role. Each node in the Dremio cluster must be configure accordingly.

Dremio Coordinators

To configure a coordinator node with the master-coordinator role, use the following Dremio services configuration.

Coordinator configuration

services: {
  coordinator.enabled: true,
  coordinator.master.enabled: true,
  executor.enabled: false
}

Configure multiple secondary coordinator nodes to improve concurrency and distribute query planning for ODBC and JDBC client requests to your deployment. To distribute queries across your deployment, Dremio recommends that you also configure ZooKeeper.

Secondary coordinator nodes run ODBC and JDBC queries only from clients that connect to the secondary coordinator either directly or with a load balancer.

note

Run metadata commands only on the master coordinator, not on secondary coordinators, unless you are working with Iceberg tables or unlimited splits are enabled on the cluster.

To enable this feature for YARN-based and standalone deployments, add the following Dremio services configuration to the dremio.conf file on each secondary coordinator node in your cluster and restart your deployment:

Secondary coordinator configuration

services: {
    coordinator.enabled: true,
    coordinator.master.enabled: false,
    coordinator.web.enabled: false,
    executor.enabled: false
}

Dremio recommends a maximum of five secondary coordinator nodes for a deployment. Dremio deployments on Azure ARM do not support secondary coordinator nodes.

Executors

To configure an executor node, use the following Dremio services configuration.

Executor configuration

services: {
  coordinator.enabled: false,
  coordinator.master.enabled: false,
  executor.enabled: true
}

Additional Configuration

Dremio provides configuration to customize the behavior of services attributes.

Feature	Description	Example
Metadata Store	Manages and optimizes metadata to enable fast query performance and efficient data access. Dremio track datasets, table schemas, indexes, and query execution details through its metadata store.	`paths: { local: ${DREMIO_HOME}"/data" }`
Distributed Store	Responsible for storing metadata, query profiles, and shared resources across the cluster.	`paths: { dist: "dremioS3:///<bucket_name>/" }`
Cloud Cache	A caching layer that improves query performance by storing frequently accessed data on executors, thus minimizing the need to repeatedly fetch data from remote object storage like cloud buckets.	`services: { executor.cache: { path.db: "/your/path", path.fs: "/your/path" } }`
Wire Encryption	Configures Transport Layer Security (TLS) between Dremio nodes and with clients in several optional configurations to fit your security requirements.	`services: { coordinator.web.ssl: { enabled: true auto-certificate.enabled: true } }`
Apache Zookeeper	ZooKeeper provides coordination and service discovery in distributed deployments, especially in multi-coordinator, multi-executor setups.	`zookeeper: "masterA:2181"`
High Availability	Dremio achieves high availability in a standalone environment by configuring one active and multiple backup coordinator nodes as standbys.	`services: { coordinator: { enabled: true, master.enabled: true } }`

Configuring Basic Services​

Dremio Coordinators​

Executors​

Additional Configuration​

Configuring Basic Services

Dremio Coordinators

Executors

Additional Configuration