Apache Spark setup
profiles.yml
file is for dbt Core users onlyIf you're using dbt Cloud, you don't need to create a profiles.yml
file. This file is only for dbt Core users. To connect your data platform to dbt Cloud, refer to About data platforms.
dbt-databricks
If you're using Databricks, the dbt-databricks
adapter is recommended over dbt-spark
. If you're still using dbt-spark with Databricks consider migrating from the dbt-spark adapter to the dbt-databricks adapter.
For the Databricks version of this page, refer to Databricks setup.
- Maintained by: dbt Labs
- Authors: core dbt maintainers
- GitHub repo: dbt-labs/dbt-spark
- PyPI package:
dbt-spark
- Slack channel: db-databricks-and-spark
- Supported dbt Core version: v0.15.0 and newer
- dbt Cloud support: Supported
- Minimum data platform version: n/a
Installing dbt-spark
Use pip
to install the adapter. Before 1.8, installing the adapter would automatically install dbt-core
and any additional dependencies. Beginning in 1.8, installing an adapter does not automatically install dbt-core
. This is because adapters and dbt Core versions have been decoupled from each other so we no longer want to overwrite existing dbt-core installations.
Use the following command for installation:
Configuring dbt-spark
For Spark-specific configuration, please refer to Spark configs.
If connecting to Databricks via ODBC driver, it requires pyodbc
. Depending on your system, you can install it seperately or via pip. See the pyodbc
wiki for OS-specific installation details.
If connecting to a Spark cluster via the generic thrift or http methods, it requires PyHive
.
# odbc connections
$ python -m pip install "dbt-spark[ODBC]"
# thrift or http connections
$ python -m pip install "dbt-spark[PyHive]"
# session connections
$ python -m pip install "dbt-spark[session]"
Configuring dbt-spark
For Spark-specific configuration please refer to Spark Configuration
For further info, refer to the GitHub repository: dbt-labs/dbt-spark
Connection methods
dbt-spark can connect to Spark clusters by four different methods:
-
odbc
is the preferred method when connecting to Databricks. It supports connecting to a SQL Endpoint or an all-purpose interactive cluster. -
thrift
connects directly to the lead node of a cluster, either locally hosted / on premise or in the cloud (e.g. Amazon EMR). -
http
is a more generic method for connecting to a managed service that provides an HTTP endpoint. Currently, this includes connections to a Databricks interactive cluster. -
session
connects to a pySpark session, running locally or on a remote machine.
The session
connection method is intended for advanced users and experimental dbt development. This connection method is not supported by dbt Cloud.
ODBC
Use the odbc
connection method if you are connecting to a Databricks SQL endpoint or interactive cluster via ODBC driver. (Download the latest version of the official driver here.)
your_profile_name:
target: dev
outputs:
dev:
type: spark
method: odbc
driver: [path/to/driver]
schema: [database/schema name]
host: [yourorg.sparkhost.com]
organization: [org id] # Azure Databricks only
token: [abc123]
# one of:
endpoint: [endpoint id]
cluster: [cluster id]
# optional
port: [port] # default 443
user: [user]
server_side_parameters:
"spark.driver.memory": "4g"
Thrift
Use the thrift
connection method if you are connecting to a Thrift server sitting in front of a Spark cluster, e.g. a cluster running locally or on Amazon EMR.
your_profile_name:
target: dev
outputs:
dev:
type: spark
method: thrift
schema: [database/schema name]
host: [hostname]
# optional
port: [port] # default 10001
user: [user]
auth: [e.g. KERBEROS]
kerberos_service_name: [e.g. hive]
use_ssl: [true|false] # value of hive.server2.use.SSL, default false
server_side_parameters:
"spark.driver.memory": "4g"
HTTP
Use the http
method if your Spark provider supports generic connections over HTTP (e.g. Databricks interactive cluster).
your_profile_name:
target: dev
outputs:
dev:
type: spark
method: http
schema: [database/schema name]
host: [yourorg.sparkhost.com]
organization: [org id] # Azure Databricks only
token: [abc123]
cluster: [cluster id]
# optional
port: [port] # default: 443
user: [user]
connect_timeout: 60 # default 10
connect_retries: 5 # default 0
server_side_parameters:
"spark.driver.memory": "4g"
Databricks interactive clusters can take several minutes to start up. You may
include the optional profile configs connect_timeout
and connect_retries
,
and dbt will periodically retry the connection.
Session
Use the session
method if you want to run dbt
against a pySpark session.
your_profile_name:
target: dev
outputs:
dev:
type: spark
method: session
schema: [database/schema name]
host: NA # not used, but required by `dbt-core`
server_side_parameters:
"spark.driver.memory": "4g"
Optional configurations
Retries
Intermittent errors can crop up unexpectedly while running queries against Apache Spark. If retry_all
is enabled, dbt-spark will naively retry any query that fails, based on the configuration supplied by connect_timeout
and connect_retries
. It does not attempt to determine if the query failure was transient or likely to succeed on retry. This configuration is recommended in production environments, where queries ought to be succeeding.
For instance, this will instruct dbt to retry all failed queries up to 3 times, with a 5 second delay between each retry:
retry_all: true
connect_timeout: 5
connect_retries: 3
Server side configuration
Spark can be customized using Application Properties. Using these properties the execution can be customized, for example, to allocate more memory to the driver process. Also, the Spark SQL runtime can be set through these properties. For example, this allows the user to set a Spark catalogs.
Caveats
When facing difficulties, run poetry run dbt debug --log-level=debug
. The logs are saved at logs/dbt.log
.
Usage with EMR
To connect to Apache Spark running on an Amazon EMR cluster, you will need to run sudo /usr/lib/spark/sbin/start-thriftserver.sh
on the master node of the cluster to start the Thrift server (see the docs for more information). You will also need to connect to port 10001, which will connect to the Spark backend Thrift server; port 10000 will instead connect to a Hive backend, which will not work correctly with dbt.
Supported functionality
Most dbt Core functionality is supported, but some features are only available on Delta Lake (Databricks).
Delta-only features:
- Incremental model updates by
unique_key
instead ofpartition_by
(seemerge
strategy) - Snapshots
- Persisting column-level descriptions as database comments
Default namespace with Thrift connection method
To run metadata queries in dbt, you need to have a namespace named default
in Spark when connecting with Thrift. You can check available namespaces by using Spark's pyspark
and running spark.sql("SHOW NAMESPACES").show()
. If the default namespace doesn't exist, create it by running spark.sql("CREATE NAMESPACE default").show()
.
If there's a network connection issue, your logs will display an error like Could not connect to any of [('127.0.0.1', 10000)]
(or something similar).