Manage external locations

This article describes how to list, view, update, grant permissions on, enable file events for, and delete external locations.

note

Databricks recommends governing file access using volumes. See What are Unity Catalog volumes?.

Describe an external location

To see the properties of an external location, including permissions and workspace access, you can use Catalog Explorer or a SQL command.

Catalog Explorer

1. In the sidebar, click Catalog.
2. On the Quick access page, click the External data > button to go to the External Locations tab.
3. Click the name of an external location to view its properties.

SQL

Run the following command in a notebook or the Databricks SQL editor. Replace <location-name> with the name of the external location.

SQL

DESCRIBE EXTERNAL LOCATION <location-name>;

Show grants on an external location

To show grants on an external location, use a command like the following. You can optionally filter the results to show only the grants for the specified principal.

SQL

SHOW GRANTS [<principal>] ON EXTERNAL LOCATION <location-name>;

Replace the placeholder values:

• <location-name>: The name of the external location that authorizes reading from and writing to the S3 bucket in your cloud tenant.
• <principal>: The email address of an account-level user or the name of an account-level group.

note

If a group or username contains a space or @ symbol, use back-ticks (` `) around it, not apostrophes.

Grant permissions on an external location

This section describes how to grant and revoke permissions on an external location using Catalog Explorer and SQL commands in a notebook or SQL query. For information about using the Databricks CLI or Terraform instead, see the Databricks Terraform documentation and What is the Databricks CLI?.

You can grant the following permissions on an external location:

• CREATE EXTERNAL TABLE
• CREATE EXTERNAL VOLUME
• CREATE MANAGED STORAGE

Permissions required: The CREATE EXTERNAL LOCATION privilege on both the metastore and the storage credential referenced in the external location or the MANAGE privilege on the external location. Metastore admins have CREATE EXTERNAL LOCATION on the metastore by default.

To grant permission to use an external location:

Catalog Explorer

1. In the sidebar, click Catalog.
2. On the Quick access page, click the External data > button to go to the External Locations tab.
3. Click the name of an external location to open its properties.
4. Click Permissions.
5. To grant permission to users or groups, select each identity, then click Grant.
6. To revoke permissions from users or groups, select each identity, then click Revoke.

SQL

Run the following SQL command in a notebook or SQL query editor. This example grants the ability to create an external table that references the external location:

SQL

GRANT CREATE EXTERNAL TABLE ON EXTERNAL LOCATION <location-name> TO <principal>;

Replace the placeholder values:

• <location-name>: The name of the external location that authorizes reading from and writing to the S3 bucket in your cloud tenant.
• <principal>: The email address of an account-level user or the name of an account-level group.

note

If a group or username contains a space or @ symbol, use back-ticks around it (not apostrophes). For example finance team .

Change the owner of an external location

An external location's creator is its initial owner. To change the owner to a different account-level user or group, run the following command in a notebook or the Databricks SQL editor or use Catalog Explorer.

Permissions required: External location owner or a user with the MANAGE privilege.

Replace the placeholder values:

• <location-name>: The name of the credential.
• <principal>: The email address of an account-level user or the name of an account-level group.

SQL

ALTER EXTERNAL LOCATION <location-name> OWNER TO <principal>

Mark an external location as read-only

If you want users to have read-only access to an external location, you can use Catalog Explorer to mark the external location as read-only.

Making external locations read-only:

• Prevents users from writing to files in those external locations, regardless of any write permissions granted by the IAM role that underlies the storage credential, and regardless of the Unity Catalog permissions granted on that external location.
• Prevents users from creating managed tables or volumes in those external locations.
• Enables the system to validate the external location properly at creation time.

You can mark external locations as read-only when you create them.

You can also use Catalog Explorer to change read-only status after creating an external location:

1. In the sidebar, click Catalog.
2. On the Quick access page, click the External data > button to go to the External Locations tab.
3. Select the external location, click the menu next to the Test connection button, and select Edit.
4. On the edit dialog, click Advanced Options and select the Limit to read-only use option.
5. Click Update.

Configure an encryption algorithm on an external location

AWS supports server-side encryption (SSE) with Amazon S3 managed keys (SSE-S3) or AWS KMS keys (SSE-KMS) for protecting data in S3. If your S3 bucket requires SSE encryption, you can configure an encryption algorithm in your external location to allow external tables and volumes in Unity Catalog to access data in your S3 bucket. SSE is not supported with external tables shared using Delta Sharing. For more information, see Configure encryption for S3 with KMS.

note

To learn how to configure SSE-3 and SSE-KMS keys for buckets that you use as external locations, see Step 1: Create or select a key in AWS KMS.

1. In the sidebar, click Catalog.

2. At the top of the Catalog pane, click the gear icon and select External Locations.

3. Select the external location. The external location must use an IAM role for a storage credential.

4. Click the kebab menu next to the Test connection button, and select Edit.

5. On the edit dialog, click Advanced Options.

6. Under Encryption Algorithm select SSE-SE or SSE-KMS depending on your encryption key.

   For SSE-KMS, under Encryption KMS key arn paste the ARN of the KMS key referenced by clients when accessing the S3 location.

7. Click Update.

(Recommended) Enable file events for an external location

Preview

This feature is in Public Preview.

If you want to ingest change notifications that are pushed by the cloud provider, enabling file events for the external location has the following advantages:

• Makes it easier to set up file notifications for Auto Loader. Specifically, it enables incremental file discovery with notification-like performance in Auto Loader by setting cloudFiles.useManagedFileEvents to true. See Configure Auto Loader streams in file notification mode.
• Improves the efficiency and capacity of file arrival triggers for jobs. See Trigger jobs when new files arrive.

Before you begin

If you want Databricks to configure SQS queues in S3 on your behalf, your external location must reference a storage credential that gives adequate permissions to do so. See the next step for instructions.

If you want to create your own SQS queues in S3, the identity represented by the storage credential must have the following permission on those SQS queues:

• sqs:ReceiveMessage
• sqs:DeleteMessage
• sqs:PurgeQueue

Step 1: Confirm that Databricks has access to file events in S3

Before you can enable file events for the external location securable object, you must ensure that your S3 account is configured to give Databricks access to the file events that it emits. If you want Databricks to configure file events in S3 for you, you must also ensure that Databricks has the proper access.

Assigning this access is a recommended step when you configure IAM roles that can access S3 buckets using Databricks and Unity Catalog. To verify that Databricks can configure and subscribe to your bucket's event notifications:

1. Get the IAM role.

   1. In the sidebar, click Catalog.

   2. On the Quick access page, click the External data > button to go to the External Locations tab.

   3. Select the external location.

   4. On the Overview tab, click the Credential name.

   5. On the storage credential Overview tab, copy the IAM role (ARN).

      You will use this in the next step.

2. Log into your AWS account.

3. Go to IAM and search for the role that you copied in step 1.

4. Under Permissions policies, find the IAM policy or policies associated with the IAM role and open it.

5. Open the policy or policies and confirm that there is one that includes the following properties.

   This policy allows your Databricks account to update your bucket's event notification configuration, create an SNS topic, create an SQS queue, and subscribe the SQS queue to the SNS topic.

   Replace <BUCKET> with the name of your S3 bucket.

   JSON

   {
     "Version": "2012-10-17",
     "Statement": [
       {
         "Sid": "ManagedFileEventsSetupStatement",
         "Effect": "Allow",
         "Action": [
           "s3:GetBucketNotification",
           "s3:PutBucketNotification",
           "sns:ListSubscriptionsByTopic",
           "sns:GetTopicAttributes",
           "sns:SetTopicAttributes",
           "sns:CreateTopic",
           "sns:TagResource",
           "sns:Publish",
           "sns:Subscribe",
           "sqs:CreateQueue",
           "sqs:DeleteMessage",
           "sqs:ReceiveMessage",
           "sqs:SendMessage",
           "sqs:GetQueueUrl",
           "sqs:GetQueueAttributes",
           "sqs:SetQueueAttributes",
           "sqs:TagQueue",
           "sqs:ChangeMessageVisibility",
           "sqs:PurgeQueue"
         ],
         "Resource": ["arn:aws:s3:::<BUCKET>", "arn:aws:sqs:*:*:csms-*", "arn:aws:sns:*:*:csms-*"]
       },
       {
         "Sid": "ManagedFileEventsListStatement",
         "Effect": "Allow",
         "Action": ["sqs:ListQueues", "sqs:ListQueueTags", "sns:ListTopics"],
         "Resource": ["arn:aws:sqs:*:*:csms-*", "arn:aws:sns:*:*:csms-*"]
       },
       {
         "Sid": "ManagedFileEventsTeardownStatement",
         "Effect": "Allow",
         "Action": ["sns:Unsubscribe", "sns:DeleteTopic", "sqs:DeleteQueue"],
         "Resource": ["arn:aws:sqs:*:*:csms-*", "arn:aws:sns:*:*:csms-*"]
       }
     ]
   }

   See also Step 1: Create an IAM role.

6. If this policy is missing, add it to the IAM role.

Step 2: Enable file events for the external location using Catalog Explorer

To enable file events:

1. In the sidebar, click Catalog.

2. On the Quick access page, click the External data > button to go to the External Locations tab.

3. Select the external location.

4. Click the kebab menu next to the Test connection button, and select Edit.

5. On the edit dialog, click Advanced Options.

6. Select Enable file events.

7. Select the File event type:

   Automatic: (Recommended) select this if you want Databricks to set up subscriptions and events for you.

   Provided: Select this if you have already configured an SQS queue yourself.

8. If you selected the Provided file event type, enter the Queue URL of the existing SQS queue: https://sqs.<region>.amazonaws.com/<account-ID>/<queue-name>.

9. Click Update.

10. Wait a few seconds and click Test connection on the main external location edit page to confirm that file events have been enabled successfully.

File events limitations

File events on external locations have the following limitations:

• Event throughput is limited to 2000 files ingested per second.

• You cannot tag cloud resources using the resourceTags option. Instead, tag resources using the cloud console after the Auto Loader service creates your queue and subscription resources.

• You can't set up file events for the Unity Catalog metastore root storage location if no external location is defined for that storage location.

  You can't set up file events on storage locations that have no external location object defined in Unity Catalog. Some implementations of Unity Catalog include a metastore root storage location that is not associated with an external location. To determine if this is the case for your metastore root storage location:

  1. As an account admin, log in to the account console.

  2. Click Catalog.

  3. Click the metastore name.

  4. Go to the Configuration tab.

  5. If there is a S3 bucket path value, then your metastore root has no external location object defined for it.

     To update the metastore root storage to use an external location, click the Remove button. An external location will be created for you. For details, see Remove metastore-level storage.

Modify an external location

An external location's owner or a user with the MANAGE privilege can rename, change the URI, and change the storage credential of the external location.

To rename an external location, do the following:

Run the following command in a notebook or the Databricks SQL editor. Replace the placeholder values:

• <location-name>: The name of the location.
• <new-location-name>: A new name for the location.

SQL

ALTER EXTERNAL LOCATION <location-name> RENAME TO <new-location-name>;

To change the URI that an external location points to in your cloud tenant, do the following:

Run the following command in a notebook or the Databricks SQL editor. Replace the placeholder values:

• <location-name>: The name of the external location.
• <url>: The new storage URL the location should authorize access to in your cloud tenant.

SQL

ALTER EXTERNAL LOCATION location_name SET URL '<url>' [FORCE];

The FORCE option changes the URL even if external tables depend upon the external location.

To change the storage credential that an external location uses, do the following:

Run the following command in a notebook or the Databricks SQL editor. Replace the placeholder values:

• <location-name>: The name of the external location.
• <credential-name>: The name of the storage credential that grants access to the location's URL in your cloud tenant.

SQL

ALTER EXTERNAL LOCATION <location-name> SET STORAGE CREDENTIAL <credential-name>;

Delete an external location

To delete (drop) an external location you must be its owner or have the MANAGE privilege on the external location. To delete an external location, do the following:

Run the following command in a notebook or the Databricks SQL editor. Items in brackets are optional. Replace <location-name> with the name of the external location.

SQL

DROP EXTERNAL LOCATION [IF EXISTS] <location-name>;