Please use the form below to provide your feedback. Because your feedback is valuable to us, the information you submit in this form is recorded in our issue tracking system (JIRA), which is publicly available. You can track the status of your feedback using the ticket number displayed in the dialog once you submit the form.

A newer version of this documentation is available.

View Latest

Managing Tombstones

      +

      Sync Gateway’s Tombstones are the means by which mobile clients are notified that a document has been deleted.

      Purging Tombstones

      To remove tombstones, you need to purge them. The following tables describe how to purge tombstones (automatically or manually) and reset the Sync Gateway channel cache when Shared Bucket Access is enabled or disabled.

      Automatic purging of tombstones

      enable_shared_bucket_access: false

      enable_shared_bucket_access: true

      Tombstones are not automatically purged from the bucket. Tombstones can be purged by setting a server expiry on tombstone documents. This can be easily automated via Sync Gateway using the expiry() function in the Sync Function. The expiry time should be sufficient (perhaps a week, or a month) to allow for all other devices to sync and receive the delete notification.

      Tombstones are automatically purged from the bucket based on the server’s metadata purge interval.

      Manually purging tombstones

      enable_shared_bucket_access: false

      enable_shared_bucket_access: true

      Tombstones can be manually removed via Sync Gateway’s /\{tkn-db}/_purge endpoint, or deleting documents directly in the bucket.

      Tombstones can be manually removed via Sync Gateway’s /\{tkn-db}/_purge endpoint.

      Purging of tombstones is also required on Couchbase Lite. For example, you might decide that if a document is deleted on a Couchbase Lite client, that you want to purge the document (on that device) as soon as the delete has been successfully replicated out to Sync Gateway.

      Cache Ejection

      Deleted/expired tombstones aren’t automatically ejected from Sync Gateway’s in-memory channel caches. The following table describes how to eject Sync Gateway’s cache.

      enable_shared_bucket_access: false enable_shared_bucket_access: true

      For tombstones purged on Couchbase Server

      • Restarting Sync Gateway will flush the cache

      • Restarting Sync Gateway will flush the cache.

      • Starting in 2.1.1, running the /\{tkn-db}/_compact endpoint will remove purged tombstones from the channel cache.

      For documents purged on Sync Gateway

      • Restarting Sync Gateway will flush the cache.

      • Starting in 2.1.1, this is done automatically.

      • Restarting Sync Gateway will flush the cache.

      • Starting in 2.1.1, this is done automatically.

      Tombstone Lifecycle

      The storage location of tombstones differs slightly depending on whether the Shared Bucket Access feature is enabled (enable_shared_bucket_access: true). The table below describes those differences.

      enable_shared_bucket_access: false enable_shared_bucket_access: true

      Mobile metadata storage location

      Persisted on the document (doc._sync)

      Persisted as system extended attributes (xattr._sync)

      Tombstone storage location

      Persisted on the document

      Persisted as system extended attributes (xattr._sync).

      Additional user properties on a tombstone

      Persisted on the document

      Not persisted

      Additional system properties on a tombstone

      Persisted on the document

      Not persisted

      Document operations also have a different impact on tombstones when Shared Bucket Access is enabled/disabled.

      enable_shared_bucket_access: false enable_shared_bucket_access: true

      Deleting a document through Sync Gateway

      Creates a tombstone

      Creates a tombstone

      Purging a document through Sync Gateway

      Removes the document and metadata

      Removes the document and metadata

      Deleting a document body in the bucket (SDK, N1QL, expiry)

      Removes the document and metadata

      Creates a tombstone

      Purging a document’s metadata (on Couchbase Server)

      N/A

      Removes the tombstone metadata

      Related Content

      API Topics
      Reference
      Community