README.md

ADB workspace with external hive metastore

Credits to [email protected] and [email protected] for notebook logic for database initialization steps. This architecture will be deployed:

Get Started:

On your local machine, inside this folder of adb-external-hive-metastore:

1. Clone the tf_azure_deployment repository to local.

2. Supply with your terraform.tfvars file to overwrite default values accordingly. See inputs section below on optional/required variables.

3. For step 2, variables for db_username and db_password, you can also use your environment variables: terraform will automatically look for environment variables with name format TF_VAR_xxxxx.

   export TF_VAR_db_username=yoursqlserveradminuser

   export TF_VAR_db_password=yoursqlserveradminpassword

4. Init terraform and apply to deploy resources:

   terraform init

   terraform apply

Step 4 automatically completes 99% steps. The last 1% step is to manually trigger the deployed job to run once.

Go to databricks workspace - Job - run the auto-deployed job only once; this is to initialize the database with metastore schema.

Then you can verify in a notebook:

We can also check inside the sql db (metastore), we've successfully linked up cluster to external hive metastore and registered the table here:

Now you can config all other clusters to use this external metastore, using the same spark conf and env variables of cold start cluster.

Notes: Migrate from your existing managed metastore to external metastore

Refer to tutorial: https://kb.databricks.com/metastore/create-table-ddl-for-metastore.html

dbs = spark.catalog.listDatabases()
for db in dbs:
    f = open("your_file_name_{}.ddl".format(db.name), "w")
    tables = spark.catalog.listTables(db.name)
    for t in tables:
        DDL = spark.sql("SHOW CREATE TABLE {}.{}".format(db.name, t.name))
        f.write(DDL.first()[0])
        f.write("\n")
    f.close()

Module creates:

• Resource group with random prefix
• Tags, including Owner, which is taken from az account show --query user
• VNet with public and private subnet
• Databricks workspace
• External Hive Metastore for ADB workspace
• Private endpoint connection to external metastore

Requirements

Name	Version
azurerm	=2.83.0
databricks	0.3.10

Providers

Name	Version
azurerm	2.83.0
databricks	0.3.10
external	2.1.0
random	3.1.0

Modules

No modules.

Resources

Name	Type
azurerm_databricks_workspace.this	resource
azurerm_key_vault.akv1	resource
azurerm_key_vault_access_policy.example	resource
azurerm_key_vault_secret.hivepwd	resource
azurerm_key_vault_secret.hiveurl	resource
azurerm_key_vault_secret.hiveuser	resource
azurerm_mssql_database.sqlmetastore	resource
azurerm_mssql_server.metastoreserver	resource
azurerm_mssql_server_extended_auditing_policy.mssqlpolicy	resource
azurerm_mssql_virtual_network_rule.sqlservervnetrule	resource
azurerm_network_security_group.this	resource
azurerm_private_dns_zone.dnsmetastore	resource
azurerm_private_dns_zone_virtual_network_link.metastorednszonevnetlink	resource
azurerm_private_endpoint.sqlserverpe	resource
azurerm_resource_group.this	resource
azurerm_storage_account.sqlserversa	resource
azurerm_subnet.plsubnet	resource
azurerm_subnet.private	resource
azurerm_subnet.public	resource
azurerm_subnet.sqlsubnet	resource
azurerm_subnet_network_security_group_association.private	resource
azurerm_subnet_network_security_group_association.public	resource
azurerm_virtual_network.sqlvnet	resource
azurerm_virtual_network.this	resource
databricks_cluster.coldstart	resource
databricks_global_init_script.metastoreinit	resource
databricks_job.metastoresetup	resource
databricks_notebook.ddl	resource
databricks_secret_scope.kv	resource
random_string.naming	resource
azurerm_client_config.current	data source
databricks_current_user.me	data source
databricks_node_type.smallest	data source
databricks_spark_version.latest_lts	data source
external_external.me	data source

Inputs

Name	Description	Type	Default	Required
cold_start	if true, will spin up a cluster to download hive jars to dbfs	bool	true	no
db_password	Database administrator password	string	n/a	yes
db_username	Database administrator username	string	n/a	yes
dbfs_prefix	n/a	string	"dbfs"	no
no_public_ip	n/a	bool	true	no
private_subnet_endpoints	n/a	list	[]	no
rglocation	n/a	string	"southeastasia"	no
spokecidr	n/a	string	"10.179.0.0/20"	no
sqlvnetcidr	n/a	string	"10.178.0.0/20"	no
workspace_prefix	n/a	string	"adb"	no

Outputs

Name	Description
arm_client_id	n/a
arm_subscription_id	n/a
arm_tenant_id	n/a
azure_region	n/a
databricks_azure_workspace_resource_id	n/a
resource_group	n/a
workspace_url	n/a