Microsoft has entered the final phase of retiring Azure SQL Data Sync, blocking new deployments in subscriptions that have never used the service.

The restriction took effect on September 9, ahead of the service's shutdown on September 30, 2027.

Subscriptions that already use the service can continue creating, modifying, and managing sync groups and member databases until retirement. Other subscriptions can no longer adopt it.

The service uses a hub-and-spoke model, with an Azure SQL database serving as the hub and other databases joining its synchronization group. Members can be other Azure SQL databases or on-premises SQL Server databases, which require a sync agent. A conflict resolution policy determines whether the hub or member database takes precedence when changes clash.

SQL Data Sync supports scenarios including hybrid environments, in which applications and databases are split between local infrastructure and Azure, as well as geographically distributed applications.

Microsoft acknowledged that customers will need to choose among several possible replacements. It offered little technical explanation for the retirement, referring only to evolving "operational, security, and compliance requirements."

Microsoft announced the retirement two years ago, but blocking first-time deployments gives customers another reason to begin planning their transition. Microsoft lists alternatives including Azure Data Factory, Azure Functions, read replicas, linked servers, database mirroring, availability groups, and transactional replication. However, it noted that "there is no single replacement that maps to every SQL Data Sync configuration."

Existing users have just over a year to migrate before the final cutoff. Those without a migration plan will need one before the service shuts down. ®