Amazon Neptune Engine Version (2022-10-26) - Amazon Neptune

Amazon Neptune Engine Version (2022-10-26)

As of 2022-10-26, engine version is being generally deployed. Please note that it takes several days for a new release to become available in every region.


If upgrading from an engine version earlier than

  • Engine release introduced a new format for custom parameter groups and custom cluster parameter groups. As a result, if you are upgrading from an engine version earlier than to engine version or above, you must re-create all your existing custom parameter groups and custom cluster parameter groups using parameter group family neptune1.2. Earlier releases used parameter group family neptune1, and those parameter groups won't work with release and above. See Amazon Neptune parameter groups for more information.

  • Engine release also introduced a new format for undo logs. As a result, any undo logs created by an earlier engine version must be purged and the UndoLogsListSize CloudWatch metric must fall to zero before any upgrade from a version earlier than can get started. If there are too many undo log records (200,000 or more) when you try to start an update, the upgrade attempt can time out while waiting for purging of the undo logs to complete.

    You can speed up the purge rate by upgrading the cluster's writer instance, which is where the purging occurs. Doing that before trying to upgrade can bring down the number of undo logs before you start. Increasing the size of the writer to a 24XL instance type can increase your purge rate to more than a million records per hour.

    If the UndoLogsListSize CloudWatch metric is extremely large, opening a support case may help you explore additional strategies for bringing it down.

  • Finally, there was a breaking change in release affecting earlier code that used the Bolt protocol with IAM authentication. Starting with release, Bolt needs a resource path for IAM signing. In Java, setting the resource path might look like this: request.setResourcePath("/openCypher"));. In other languages, the /openCypher can be appended to the endpoint URI. See Using the Bolt protocol for examples.

Subsequent Patch Releases for This Release

New Features in This Engine Release

  • Introduced Amazon Neptune Serverless, an on-demand autoscaling configuration that scales your DB cluster up to meet increases in processing demand and then down again when the demand decreases.

Improvements in This Engine Release

  • Improved performance of Gremlin order-by queries. Gremlin queries with an order-by at the end of a NeptuneGraphQueryStep now use a larger chunk size for better performance. This does not apply to order-by on an internal (non-root) node of the query plan.

  • Improved performance of Gremlin update queries. Vertices and edges must now be locked against deletion while adding edges or properties. This change eliminates duplicate locks within a transaction, which improves performance.

  • Improved performance of Gremlin queries that use dedup() inside of a repeat() subquery by pushing the dedup down to the native execution layer.

  • Added user-friendly error messages for IAM authentication errors. These messages now show the your IAM user or role ARN, the resource ARN, and a list of unauthorized actions for the request. The list of unauthorized actions helps you see what might be missing or explicitly denied in the IAM policy that you're using.

Defects Fixed in This Engine Release

  • Fixed a Gremlin bug where using PartitionStrategy after upgrading to TinkerPop 3.5 incorrectly resulted an error with the message, "PartitionStrategy does not work with anonymous Traversals," which prevented the traversal from being executed.

  • Fixed a Gremlin correctness bug involving WherePredicateStep translation, where Neptune's query engine was producing incorrect results for queries using where(P.neq('x')) and variations of that.

  • Fixed an openCypher bug in the MERGE clause that in some cases caused duplicate node and edge creation.

  • Fixed a SPARQL bug in the handling of queries that contain (NOT) EXISTS within an OPTIONAL clause, where in some cases query results were missing.

  • Fixed a bulk loader bug that caused performance regressions under heavy insertion loads.

Query-Language Versions Supported in This Release

Before upgrading a DB cluster to version, make sure that your project is compatible with these query-language versions:

  • Gremlin earliest version supported: 3.5.2

  • Gremlin latest version supported: 3.5.4

  • openCypher version: Neptune-9.0.20190305-1.0

  • SPARQL version: 1.1

Upgrade Paths to Engine Release

Upgrading to This Release

Amazon Neptune is now generally available.

If a DB cluster is running an engine version from which there is an upgrade path to this release, it is eligible to be upgraded now. You can upgrade any eligible cluster using the DB cluster operations on the console or by using the SDK. The following CLI command will upgrade an eligible cluster immediately:

For Linux, OS X, or Unix:

aws neptune modify-db-cluster \ --db-cluster-identifier (your-neptune-cluster) \ --engine-version \ --apply-immediately

For Windows:

aws neptune modify-db-cluster ^ --db-cluster-identifier (your-neptune-cluster) ^ --engine-version ^ --apply-immediately

Updates are applied to all instances in a DB cluster simultaneously. An update requires a database restart on those instances, so you will experience downtime ranging from 20–30 seconds to several minutes, after which you can resume using the DB cluster.

Always test before you upgrade

When a new major or minor Neptune engine version is released, always test your Neptune applications on it first before upgrading to it. Even a minor upgrade could introduce new features or behavior that would affect your code.

Start by comparing the release notes pages from your current version to those of the targeted version to see if there will be changes in query language versions or other breaking changes.

The best way to test a new version before upgrading your production DB cluster is to clone your production cluster so that the clone is running the new engine version. You can then run queries on the clone without affecting the production DB cluster.

Always create a manual snapshot before you upgrade

Before performing an upgrade, we strongly recommend that you always create a manual snapshot of your DB cluster. Having an automatic snapshot only offers short-term protection, whereas a manual snapshot remains available until you explicitly delete it.

In certain cases Neptune creates a manual snapshot for you as a part of the upgrade process, but you should not rely on this, and should create your own manual snapshot in any case.

When you are certain that you won't need to revert your DB cluster to its pre-upgrade state, you can explicitly delete the manual snapshot that you created yourself, as well as the manual snapshot that Neptune might have created. If Neptune creates a manual snapshot, it will have a name that begins with preupgrade, followed by the name of your DB cluster, the source engine version, the target engine version, and the date.


If you are trying to upgrade while a pending action is in process, you may encounter an error such as the following:

We're sorry, your request to modify DB cluster (cluster identifier) has failed. Cannot modify engine version because instance (instance identifier) is running on an old configuration. Apply any pending maintenance actions on the instance before proceeding with the upgrade.

If you encounter this error, wait for the pending action to finish, or trigger a maintenance window immediately to let the previous upgrade complete.

For more information about upgrading your engine version, see Maintaining your Amazon Neptune DB Cluster. If you have any questions or concerns, the AWS Support team is available on the community forums and through AWS Premium Support.