Neptune Lab Mode - Amazon Neptune
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Neptune Lab Mode

You can use Amazon Neptune lab mode to enable new features that are in the current Neptune engine release, but that aren't yet ready for production use and aren't enabled by default. This lets you try out these features in your development and test environments.


This feature is available starting with Release (2019-10-15).

Using Neptune Lab Mode

Use the neptune_lab_mode DB cluster parameter to enable or disable features. You do this by including (feature name)=enabled or (feature name)=disabled in the value of the neptune_lab_mode parameter in the DB Cluster Parameter group.

For example, in this engine release you might set the neptune_lab_mode parameter to Streams=disabled, ReadWriteConflictDetection=enabled.

For information about how to edit the DB cluster parameter group for your database, see Editing a Parameter Group. Note that you cannot edit the default DB cluster parameter group; if you are using the default group, you must create a new DB cluster parameter group before you can set the neptune_lab_mode parameter.


When you make a change to a static DB cluster parameter such as neptune_lab_mode, you must re-start the primary (writer) instance of the cluster for the change to take effect. Before Release: (2022-07-21), all the read-replicas in a DB cluster would then automatically be rebooted when the primary instance restarted.

Beginning with Release: (2022-07-21), restarting the primary instance does not cause any of the replicas to restart. This means that you must restart each instance separately to pick up a DB cluster parameter change (see Parameter groups).


At present, if you supply the wrong lab-mode parameters or your request fails for another reason, you may not be notified of the failure. You should always verify that a lab-mode change request has succeeded by calling the status API as shown below:

curl -G https://your-neptune-endpoint:port/status

The status results include lab-mode information which will show whether or not the changes you requested were made:

{ "status":"healthy", "startTime":"Wed Dec 29 02:29:24 UTC 2021", "dbEngineVersion":"development", "role":"writer", "dfeQueryEngine":"viaQueryHint", "gremlin":{"version":"tinkerpop-3.5.2"}, "sparql":{"version":"sparql-1.1"}, "opencypher":{"version":"Neptune-9.0.20190305-1.0"}, "labMode":{ "ObjectIndex":"disabled", "ReadWriteConflictDetection":"enabled" }, "features":{ "LookupCache":{"status":"Available"}, "ResultCache":{"status":"disabled"}, "IAMAuthentication":"disabled", "Streams":"disabled", "AuditLog":"disabled" }, "settings":{"clusterQueryTimeoutInMs":"120000"} }

The following features are currently accessed using lab mode:

The OSGP index

Neptune can now maintain a fourth index, namely the OSGP index, which is useful for data sets having a large number of predicates (see Enabling an OSGP Index).


This feature is available starting in Neptune engine release

You can enable an OSGP index in a new, empty Neptune DB cluster by setting ObjectIndex=enabled in the neptune_lab_mode DB cluster parameter. An OSGP index can only be enabled in a new, empty DB cluster.

By default, the OSGP index is disabled.


After setting the neptune_lab_mode DB cluster parameter so as to enable the OSGP index, you must restart the writer instance of the cluster for the change to take effect.


If you disable an enabled OSGP index by setting ObjectIndex=disabled and then later re-enable it after adding more data, the index will not build correctly. On-demand rebuilding of the index is not supported, so you should only enable the OSGP index when the database is empty.

Formalized Transaction Semantics

Neptune has updated the formal semantics for concurrent transactions (see Transaction Semantics in Neptune).

Use ReadWriteConflictDetection as the name in the neptune_lab_mode parameter that enables or disables formalized transaction semantics.

By default, formalized transaction semantics are already enabled. If you want to revert to the earlier behavior, include ReadWriteConflictDetection=disabled in the value set for the DB Cluster neptune_lab_mode parameter.

Extended datetime support

Neptune has extended support for the datetime functionality. To enable datetime with extended formats, include DatetimeMillisecond=enabled in the value set for the DB Cluster neptune_lab_mode parameter.