Export metadata from Dataproc Metastore

This page explains how to export metadata from Dataproc Metastore.

The export metadata feature lets you save your metadata in a portable storage format.

After you export your data, you can then import the metadata into another Dataproc Metastore service or a self-managed Hive Metastore (HMS).

About exporting metadata

When you export metadata from Dataproc Metastore, the service stores the data in one of the following file formats:

A set of Avro files stored in a folder.
A single MySQL dump file stored in a Cloud Storage folder.

Avro

Avro based exports are only supported for Hive versions 2.3.6 and 3.1.2. When you export Avro files, Dataproc Metastore creates a <table-name>.avro file for each table in your database.

To export Avro files, your Dataproc Metastore service can use the MySQL or Spanner database type.

MySQL

MySQL based exports are supported for all versions of Hive. When you export MySQL files, Dataproc Metastore creates a single SQL file that contains all your table information.

To export MySQL files, your Dataproc Metastore service must use the MySQL database type. The Spanner database type doesn't support MySQL imports.

Before you begin

Enable Dataproc Metastore in your project.
Understand networking requirements specific to your project.
Create a Dataproc Metastore service.

Required roles

To get the permissions that you need to export metadata into Dataproc Metastore, ask your administrator to grant you the following IAM roles:

To export metadata, either:
- Dataproc Metastore Editor (roles/metastore.editor) on the Dataproc Metastore service
- Dataproc Metastore Administrator (roles/metastore.admin) on the Dataproc Metastore service
- Dataproc Metastore Metadata Operator (roles/metastore.metadataOperator) on the Dataproc Metastore service
For MySQL and Avro, to use the Cloud Storage object for export: grant your user account and the Dataproc Metastore service agent the Storage Creator role (roles/storage.objectCreator) on the Cloud Storage bucket

For more information about granting roles, see Manage access.

These predefined roles contain the permissions required to export metadata into Dataproc Metastore. To see the exact permissions that are required, expand the Required permissions section:

Required permissions

The following permissions are required to export metadata into Dataproc Metastore:

To export metadata: metastore.services.export on the metastore service
For MySQL and Avro, to use the Cloud Storage object for export, grant your user account and the Dataproc Metastore service agent: storage.objects.create on the Cloud Storage bucket

You might also be able to get these permissions with custom roles or other predefined roles.

For more information about specific Dataproc Metastore roles and permissions, see Dataproc Metastore IAM overview.

Export metadata

Before exporting your metadata, note the following considerations:

While an export is running, you can't update a Dataproc Metastore service — for example changing configuration settings. However, you can still use it for normal operations, such as using it to access its metadata from attached Dataproc or self-managed clusters.
The metadata export feature only exports metadata. Data that's created by Apache Hive in internal tables isn't replicated in the export.

To export metadata from a Dataproc Metastore service, perform the following steps.

Console

In the Google Cloud console, open the Dataproc Metastore page:

Open Dataproc Metastore
On the Dataproc Metastore page, click the name of the service you want to export metadata from.

The Service detail page opens.
In the navigation bar, click Export.

The Export metadata page opens.
In the Destination section, choose either MySQL or Avro.
In the Destination URI field, click Browse and select the Cloud Storage URI where you want to export your files to.

You can also enter your bucket location in the provided text field. Use the following format: bucket/object or bucket/folder/object.

Note: To store your exported metadata, the export job creates a new sub folder in your Cloud Storage URI destination.
To start the export, click Submit.

When finished, your export appears in a table on the Service detail page on the Import/Export tab.

When the export completes, Dataproc Metastore automatically returns to the active state, regardless of whether or not the export succeeded.

gcloud CLI

To export metadata from a service, run the following gcloud metastore services export gcs command:
```
gcloud metastore services export gcs SERVICE \
    --location=LOCATION \
    --destination-folder=gs://bucket-name/path/to/folder \
    --dump-type=DUMP_TYPE
```
Replace the following:
- SERVICE: the name of your Dataproc Metastore service.
- LOCATION: the Google Cloud region in which your Dataproc Metastore service resides.
- bucket-name/path/to/folder: the Cloud Storage destination folder where you want to store your export.
- DUMP_TYPE: the type of database dump to be generated by the export. Accepted values include mysql and avro. The default value is mysql.
Verify that the export was successful.

When the export completes, Dataproc Metastore automatically returns to the active state, regardless of whether or not the export succeeded.

REST

Follow the API instructions to export metadata into a service by using the APIs Explorer.

When the export completes, the service automatically returns to the active state, regardless of whether or not it succeeded.

View export history

To view the export history of a Dataproc Metastore service in the Google Cloud console, complete the following steps:

In the Google Cloud console, open the Dataproc Metastore page.
In the navigation bar, click Import/Export.

Your export history appear in the Export history table.

The history displays up to the last 25 exports.

Deleting a Dataproc Metastore service also deletes all associated export history.

Troubleshoot common issues

Some common issues include the following:

For more help solving common troubleshooting issues, see Import and export error scenarios.