Azure DocumentDB Free Tier – Request for Direct Region Migration from Japan West to East Asia

There is no documented in-place region-change operation for an existing Azure DocumentDB Free Tier cluster; the supported no-data-loss approach is to keep tanuclient running, provision a separate Free Tier cluster in East Asia under another eligible subscription, and perform an online Azure Database Migration Service migration before cutover.

Recommended migration path

Resource Mover cannot move Azure DocumentDB; its supported-resource list does not include this service, so its rejection is expected.^1^

Because each subscription permits only one Free Tier cluster, the East Asia target must be created in a different subscription that is independently eligible for Free Tier. East Asia supports DocumentDB Free Tier, but region availability can still vary by subscription.^2^ Creating another subscription can also introduce separate billing ownership, governance, offer-eligibility, or tenant-policy constraints.

1. Do not delete or alter the existing cluster.
2. In an eligible second subscription, create a new Azure DocumentDB Free Tier cluster and select East Asia.
3. Prepare migration access:
   • Source user: readAnyDatabase and clusterMonitor.
   • Target user: createCollection, dropCollection, createIndex, insert, and listCollections.
   • Use native DocumentDB credentials; DMS migration jobs do not support Microsoft Entra ID authentication.
   • Record and remove TTL indexes before migration; recreate them only after validating the target.^3^
4. Azure portal → Create a resource → Azure Database Migration Service:
   • Source server type: MongoDB
   • Target server type: Azure DocumentDB (with MongoDB compatibility)
   • DMS location: East Asia, matching the target.
5. Create a migration job:
   • Select Online only if ChangeStream is enabled on the source. Online mode copies existing data and then replicates ongoing changes.
   • Otherwise, select Offline and schedule a write outage.
6. Configure connectivity:
   • For Public, add the portal middleware IP addresses and DMS static IP addresses shown by the wizard to both clusters’ firewall allow lists.
   • For Private, select the required virtual networks/subnets and run the wizard-provided commands to grant DMS Network Contributor on those networks.^3^
7. Select every required collection when creating the job; collections cannot be added afterward.
8. For an online cutover:
   • Let bulk copy finish.
   • Stop application writes to Japan West.
   • Wait until DMS reports that outstanding changes are synchronized.
   • Validate document counts, indexes, application queries, and representative reads/writes in East Asia.
   • Recreate the recorded TTL indexes.
   • Replace the backend secret with the new target connection string and resume writes.
9. Retain the Japan West cluster until production validation and rollback windows are complete.

What will and will not be preserved

• DMS can migrate selected collections and create data structures/indexes when the target credentials have the required permissions.^3^
• The destination is a new cluster, so its resource name, endpoint, credentials, and connection string are not preserved. Store the new string in your application’s secret configuration.
• Run the premigration assessment to detect unsupported collection settings, commands, indexes, and shard-key configurations before touching production.^4^

Why replication is not a Free Tier alternative

A planned region migration can normally use a cross-region replica followed by Graceful Promote, which drains replication and provides zero-data-loss switchover.^5^ However, cross-region replication requires M30 or higher, while Free Tier does not support HA and related paid-tier capabilities.^6^ It therefore is not applicable while tanuclient remains Free Tier.

If another eligible subscription is unavailable

Two alternatives remain:

• Ask for an exception: Portal → Help + support → Create a support request → Service and subscription limits (quotas) → Other Requests. Describe the request as a temporary second-Free-Tier review for a region migration. Subscription-management and quota requests are available without a paid technical-support plan.^7^
  The one-Free-Tier-per-subscription rule is documented, but a temporary exception is not documented as an adjustable quota or guaranteed entitlement.
• Use a temporary paid target: Migrate Japan West Free Tier to a paid East Asia cluster. A paid cluster cannot later be downgraded to Free Tier.^2^ To finish on Free Tier, this requires a second migration: retire the original only after validation, create an East Asia Free Tier cluster in the original subscription, migrate again from the paid target, validate, and perform a second cutover.

No public documentation establishes an entitlement to a direct engineering-assisted backend region move or free engineering engagement. Microsoft Q&A cannot authorize or modify resources; backend intervention requires an Azure support case. Do not post subscription IDs, resource IDs, credentials, or connection strings publicly.

References

1. What is Azure Resource Mover?
2. Build applications for free with Azure DocumentDB Free Tier
3. Migrate MongoDB to Azure DocumentDB by using Azure Database Migration Service
4. Assess a MongoDB installation and plan for migration to Azure DocumentDB
5. Manage cross-region and same region replication on your Azure DocumentDB cluster
6. Reliability in Azure DocumentDB
7. Create an Azure support request