Access system document properties using Azure Cosmos DB for Apache Gremlin

APPLIES TO: Gremlin

Azure Cosmos DB for Gremlin has system properties such as _ts, _self, _attachments, _rid, and _etag on every item. Additionally, Gremlin engine adds inVPartition and outVPartition properties on edges. By default, these properties are available for traversal. However, it's possible to include specific properties, or all of them, in Gremlin traversal.

g.withStrategies(ProjectionStrategy.build().IncludeSystemProperties('_ts').create())

E-Tag

This property is used for optimistic concurrency control. If an application needs to break an operation into separate traversals, use the eTag property to avoid data loss in concurrent writes.

g.withStrategies(ProjectionStrategy.build().IncludeSystemProperties('_etag').create()).V('1').has('_etag', '"00000100-0000-0800-0000-5d03edac0000"').property('test', '1')

Time-to-live (TTL)

If a graph has document expiration enabled and documents have ttl property set on them, then this property is available in Gremlin traversal as a regular vertex or edge property. ProjectionStrategy isn't necessary to enable time-to-live property exposure.

• Use the following command to set time-to-live on a new vertex:

  g.addV(<ID>).property('ttl', <expirationTime>)
  

  For example, a vertex created with the following traversal is automatically deleted after 123 seconds:

  g.addV('vertex-one').property('ttl', 123)
  

• Use the following command to set time-to-live on an existing vertex:

  g.V().hasId(<ID>).has('pk', <pk>).property('ttl', <expirationTime>)
  

• Applying the time-to-live property on vertices doesn't automatically apply it to associated edges. This behavior occurs because edges are independent records in the database store. Use the following command to set time-to-live on vertices and all the incoming and outgoing edges of the vertex:

  g.V().hasId(<ID>).has('pk', <pk>).as('v').bothE().hasNot('ttl').property('ttl', <expirationTime>)
  

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