# Amazon Neptune Engine Version 1.2.1.0 (2023-03-08)
As of 2023-03-08, engine version 1.2.1.0 is being generally deployed. Please note that it takes several days for a new release to become available in every region.
**Note**
**If upgrading from an engine version earlier than 1.2.0.0:**
[Engine release 1.2.0.0](engine-releases-1.2.0.0.md) 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 1.2.0.0 to engine version 1.2.0.0 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 1.2.0.0 and above. See [Amazon Neptune parameter groups](parameter-groups.md) for more information.
Engine release 1.2.0.0 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`](cw-metrics.md#cw-metrics-UndoLogListSize) CloudWatch metric must fall to zero before any upgrade from a version earlier than 1.2.0.0 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 1.2.0.0 affecting earlier code that used the Bolt protocol with IAM authentication. Starting with release 1.2.0.0, 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](access-graph-opencypher-bolt.md) for examples.
## Subsequent Patch Releases for This Release
+ [Release: 1.2.1.0.R2 (2023-05-02)](engine-releases-1.2.1.0.R2.md)
+ [Release: 1.2.1.0.R3 (2023-06-13)](engine-releases-1.2.1.0.R3.md)
+ [Release: 1.2.1.0.R4 (2023-08-10)](engine-releases-1.2.1.0.R4.md)
+ [Release: 1.2.1.0.R5 (2023-09-02)](engine-releases-1.2.1.0.R5.md)
+ [Release: 1.2.1.0.R6 (2023-09-12)](engine-releases-1.2.1.0.R6.md)
+ [Release: 1.2.1.0.R7 (2023-10-06)](engine-releases-1.2.1.0.R7.md)
## New Features in This Engine Release
+ Added support for [TinkerPop 3.6.2](https://tinkerpop.apache.org/docs/3.6.2-SNAPSHOT/dev/provider/), which adds many new Gremlin features such as the new `mergeV()`, `mergeE()`, `element()`, and `fail()` steps. The `mergeV()` and `mergeE()` steps are of particular note as they offer a long-awaited declarative option for performing upsert-like operations, which should greatly simplify existing code patterns and make Gremlin easier to read. The 3.6.x version also added regex predicates, a new overload to the `property()` step which takes a `Map`, and a major revision of `by()` modulation behavior that is far more consistent across all steps which use it.
See the [TinkerPop change log](https://github.com/apache/tinkerpop/blob/3.6.0/CHANGELOG.asciidoc#release-3-6-0) and [upgrade page](https://tinkerpop.apache.org/docs/current/upgrade/) for information about the changes in version 3.6 and things to consider when upgrading.
If you are using `fold().coalesce(unfold(), )` for conditional inserts, we recommend that you migrate to the new `mergeV/E()` syntax, described [here](https://tinkerpop.apache.org/docs/3.6.0/reference/#mergevertex-step) and [here](https://tinkerpop.apache.org/docs/3.6.0/reference/#mergeedge-step). Neptune uses a narrower locking pattern for `Merge` than for `Coalesce`, which can reduce concurrent modification exceptions (CMEs).
For more information about the new features available in this TinkerPop release, see Stephen Mallette's blog, [Exploring new features of Apache TinkerPop 3.6.x in Amazon Neptune](https://aws.amazon.com/blogs/database/exploring-new-features-of-apache-tinkerpop-3-6-x-in-amazon-neptune/).
+ Added support for [R6i instance types](https://aws.amazon.com/ec2/instance-types/r6i/), powered by 3rd-generation Intel Xeon Scalable processors. These are an ideal fit for memory-intensive workloads and offer up to 15% better compute/price performance and up to 20% higher memory bandwidth per vCPU than comparable R5 instance types.
+ Added [graph summary API](neptune-graph-summary.md) endpoints for both property graphs and RDF graphs, that let you get a fast summary report about your graph.
For property (PG) graphs, the graph summary API provides a read-only list of node and edge labels and property keys, along with counts of nodes, edges, and properties. For RDF graphs, it provides a list of classes and predicate keys, along with counts of quads, subjects, and predicates.
The following changes went along with the new graph summary API:
+ Added a new [GetGraphSummary](iam-dp-actions.md#getgraphsummary) dataplane action.
+ Added a new `rdf/statistics` endpoint to replace the `sparql/statistics` endpoint, which is now deprecated.
+ Changed the name of the `summary` field in the statistics status response to `signatureInfo`, so as not to confuse it with graph summary information. Previous engine versions continue to use `summary` in the JSON response.
+ Changed the precision of the `date` field in the statistics status response from minute to millisecond. The previous format was `2020-05-07T23:13Z` (minute precision), while the new format is `2023-01-24T00:47:43.319Z` (millisecond precision). Both are ISO 8601 compliant, but this change may break existing code, depending on how the date is being parsed.
+ Added a new [`%statistics`](notebooks-magics.md#notebooks-line-magics-statistics) line magic in the Workbench that lets you retrieve DFE engine statistics.
+ Added a new [`%summary`](notebooks-magics.md#notebooks-line-magics-summary) line magic in the Workbench that lets you retrieve graph summary information.
+ Added [slow-query logging](slow-query-logs.md) to log queries that take longer to execute than a specified threshold. You enable and control slow-query logging using the two new dynamic parameters, namely [neptune\$1enable\$1slow\$1query\$1log](parameters.md#parameters-db-cluster-parameters-neptune_enable_slow_query_log), and [neptune\$1slow\$1query\$1log\$1threshold](parameters.md#parameters-db-cluster-parameters-neptune_slow_query_log_threshold).
+ Added support for two [dynamic parameters](parameter-groups.md), namely the new cluster parameters, [neptune\$1enable\$1slow\$1query\$1log](parameters.md#parameters-db-cluster-parameters-neptune_enable_slow_query_log), and [neptune\$1slow\$1query\$1log\$1threshold](parameters.md#parameters-db-cluster-parameters-neptune_slow_query_log_threshold). When you make a change to a dynamic parameter, it takes effect immediately, without requiring any instance reboot.
+ Added a Neptune-specific openCypher [removeKeyFromMap()](access-graph-opencypher-extensions.md#opencypher-compliance-removeKeyFromMap-function) function that removes a specified key from a map and returns the resulting new map.
## Improvements in This Engine Release
+ Extended Gremlin DFE support to `limit` steps with local scope.
+ Added `by()` modulation support for the Gremlin `DedupGlobalStep` in the DFE engine.
+ Added DFE support for Gremlin `SelectStep` and `SelectOneStep`.
+ Performance improvements and correctness fixes for various Gremlin operators, including `repeat`, `coalesce`, `store`, and `aggregate`.
+ Improved performance of openCypher queries involving `MERGE` and `OPTIONAL MATCH`.
+ Improved performance of openCypher queries involving `UNWIND` of a list of maps of literal values.
+ Improved performance of openCypher queries that have an `IN` filter for `id`. For example:
```
MATCH (n) WHERE id(n) IN ['1', '2', '3'] RETURN n
```
+ Added the ability to specify the base IRI for SPARQL queries using the BASE statement (see [Default base IRI for queries and updates](feature-sparql-compliance.md#opencypher-compliance-default-iri)).
+ Shortened the load processing wait time for Gremlin and openCypher edge-only bulk loads.
+ Made bulk loads resume asynchronously when Neptune restarts to avoid a lengthy wait time caused by Amazon S3 connectivity issues before failing resume attempts.
+ Improved handling of SPARQL DESCRIBE queries that have the [describeMode](sparql-query-hints-for-describe.md#sparql-query-hints-describeMode) query hint set to `"CBD"` (concise bounded description) and that involve a large number of blank nodes.
## Defects Fixed in This Engine Release
+ Fixed an openCypher bug where queries returned the string, `"null"`, instead of a null value in Bolt and SPARQL-JSON.
+ Fixed an openCypher bug in list comprehension that produced a null value rather than the values provided for the list elements.
+ Fixed an openCypher bug where byte values were not correctly serialized.
+ Fixed a Gremlin bug in `UnionStep` that occurred when an input was an edge traversing to a vertex inside a child traversal.
+ Fixed a Gremlin bug that caused a step label associated with `UnionStep` not to propagate correctly to the last step of each child traversal.
+ Fixed a Gremlin bug for the `dedup` step with labels following a `repeat` step, where the labels attached to the `dedup` step weren't available to use in query further.
+ Fixed a Gremlin bug where translating the `repeat` step inside a `union` step failed with an internal error.
+ Fixed Gremlin correctness issues for DFE queries with `limit` as a child traversal of non-union steps by falling back to Tinkerpop. Queries in a form like this are affected:
```
g.withSideEffect('Neptune#useDFE', true).V().as("a").select("a").by(out().limit(1))
```
+ Fixed a SPARQL bug where `SPARQL GRAPH` patterns would not consider the dataset supplied by a `FROM NAMED` clause.
+ Fixed a SPARQL bug where SPARQL `DESCRIBE` with some `FROM` and/or `FROM NAMED` clauses did not always correctly use data from the default graph and sometimes threw an exception. See [SPARQL DESCRIBE behavior with respect to the default graph](sparql-default-describe.md).
+ Fixed a SPARQL bug so that the correct exception message is returned when null characters are rejected.
+ Fixed a SPARQL [explain](sparql-explain.md) bug that affected plans containing a [PipelinedHashIndexJoin](sparql-explain-operators.md#sparql-explain-operator-pipeline-hash-index-join) operator.
+ Fixed a bug that caused an internal error to be thrown when a query that returns a constant value was submitted.
+ Fixed an issue with deadlock detector logic that occasionally made the engine unresponsive.
## Query-Language Versions Supported in This Release
Before upgrading a DB cluster to version 1.2.1.0, make sure that your project is compatible with these query-language versions:
+ *Gremlin earliest version supported:* `3.6.2`
+ *Gremlin latest version supported:* `3.6.2`
+ *openCypher version:* `Neptune-9.0.20190305-1.1`
+ *SPARQL version:* `1.1`
## Upgrade Paths to Engine Release 1.2.1.0
You can manually upgrade to this release from any previous Neptune engine release greater than or equal to [1.1.0.0](engine-releases-1.1.0.0.md).
**Note**
Starting with [engine release 1.2.0.0](engine-releases-1.2.0.0.md), all custom parameter groups and custom cluster parameter groups that you were using with engine versions earlier than `1.2.0.0` must now be re-created using parameter group family `neptune1.2`. Previous releases used parameter group family `neptune1`, and those parameter groups will not work with releases from `1.2.0.0` onwards. See [Amazon Neptune parameter groups](parameter-groups.md) for more information.
You will not be automatically upgraded to this major version release.
## Upgrading to This Release
Amazon Neptune 1.2.1.0 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:
```
1. aws neptune modify-db-cluster \
2. --db-cluster-identifier (your-neptune-cluster) \
3. --engine-version 1.2.1.0 \
4. --apply-immediately
```
For Windows:
```
1. aws neptune modify-db-cluster ^
2. --db-cluster-identifier (your-neptune-cluster) ^
3. --engine-version 1.2.1.0 ^
4. --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.
**Note**
If you are trying to upgrade while [a pending action is in process](manage-console-maintaining), 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](cluster-maintenance.md). If you have any questions or concerns, the AWS Support team is available on the community forums and through [AWS Premium Support](http://aws.amazon.com/support).
# Amazon Neptune Engine Version 1.2.1.0.R7 (2023-10-06)
As of 2023-10-06, engine version 1.2.1.0.R7 is being generally deployed. Please note that it takes several days for a new release to become available in every region.
**Note**
**If upgrading from an engine version earlier than 1.2.0.0:**
[Engine release 1.2.0.0](engine-releases-1.2.0.0.md) 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 1.2.0.0 to engine version 1.2.0.0 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 1.2.0.0 and above. See [Amazon Neptune parameter groups](parameter-groups.md) for more information.
Engine release 1.2.0.0 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`](cw-metrics.md#cw-metrics-UndoLogListSize) CloudWatch metric must fall to zero before any upgrade from a version earlier than 1.2.0.0 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 1.2.0.0 affecting earlier code that used the Bolt protocol with IAM authentication. Starting with release 1.2.0.0, 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](access-graph-opencypher-bolt.md) for examples.
## Defects Fixed in This Engine Release
+ Fixed a bug where in some cases a failed transaction was not closed properly.
## Query-Language Versions Supported in This Release
Before upgrading a DB cluster to version 1.2.1.0.R7, make sure that your project is compatible with these query-language versions:
+ *Gremlin earliest version supported:* `3.6.2`
+ *Gremlin latest version supported:* `3.6.2`
+ *openCypher version:* `Neptune-9.0.20190305-1.0`
+ *SPARQL version:* `1.1`
## Upgrading to This Release
Amazon Neptune 1.2.1.0.R7 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:
```
1. aws neptune modify-db-cluster \
2. --db-cluster-identifier (your-neptune-cluster) \
3. --engine-version 1.2.1.0 \
4. --apply-immediately
```
For Windows:
```
1. aws neptune modify-db-cluster ^
2. --db-cluster-identifier (your-neptune-cluster) ^
3. --engine-version 1.2.1.0 ^
4. --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.
**Note**
If you are trying to upgrade while [a pending action is in process](manage-console-maintaining), 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](cluster-maintenance.md). If you have any questions or concerns, the AWS Support team is available on the community forums and through [AWS Premium Support](http://aws.amazon.com/support).
# Amazon Neptune Engine Version 1.2.1.0.R6 (2023-09-12)
As of 2023-09-12, engine version 1.2.1.0.R6 is being generally deployed. Please note that it takes several days for a new release to become available in every region.
**Note**
**If upgrading from an engine version earlier than 1.2.0.0:**
[Engine release 1.2.0.0](engine-releases-1.2.0.0.md) 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 1.2.0.0 to engine version 1.2.0.0 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 1.2.0.0 and above. See [Amazon Neptune parameter groups](parameter-groups.md) for more information.
Engine release 1.2.0.0 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`](cw-metrics.md#cw-metrics-UndoLogListSize) CloudWatch metric must fall to zero before any upgrade from a version earlier than 1.2.0.0 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 1.2.0.0 affecting earlier code that used the Bolt protocol with IAM authentication. Starting with release 1.2.0.0, 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](access-graph-opencypher-bolt.md) for examples.
## New Features in This Engine Release
+ Released the [Neptune data API](data-api.md).
The Amazon Neptune data API provides SDK support for loading data, running queries, getting information about your data, and running machine-learning operations. It supports the Gremlin and openCypher query languages in Neptune and is available in all SDK languages. It automatically signs API requests and greatly simplifies integrating Neptune into applications.
## Defects Fixed in This Engine Release
+ Fixed a bug that could cause CPU spikes under high loads when Slow Query logs were enabled.
+ Fixed a Gremlin bug where adding an edge and its properties followed by `inV()` or `outV()` raised an `InternalFailureException`.
+ Fixed several issues with IAM role chaining that caused degraded bulk-loader performance in some cases.
## Query-Language Versions Supported in This Release
Before upgrading a DB cluster to version 1.2.1.0.R6, make sure that your project is compatible with these query-language versions:
+ *Gremlin earliest version supported:* `3.6.2`
+ *Gremlin latest version supported:* `3.6.2`
+ *openCypher version:* `Neptune-9.0.20190305-1.0`
+ *SPARQL version:* `1.1`
## Upgrading to This Release
Amazon Neptune 1.2.1.0.R6 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:
```
1. aws neptune modify-db-cluster \
2. --db-cluster-identifier (your-neptune-cluster) \
3. --engine-version 1.2.1.0 \
4. --apply-immediately
```
For Windows:
```
1. aws neptune modify-db-cluster ^
2. --db-cluster-identifier (your-neptune-cluster) ^
3. --engine-version 1.2.1.0 ^
4. --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.
**Note**
If you are trying to upgrade while [a pending action is in process](manage-console-maintaining), 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](cluster-maintenance.md). If you have any questions or concerns, the AWS Support team is available on the community forums and through [AWS Premium Support](http://aws.amazon.com/support).
# Amazon Neptune Engine Version 1.2.1.0.R5 (2023-09-02)
As of 2023-09-02, engine version 1.2.1.0.R5 is being generally deployed. Please note that it takes several days for a new release to become available in every region.
**Note**
**If upgrading from an engine version earlier than 1.2.0.0:**
[Engine release 1.2.0.0](engine-releases-1.2.0.0.md) 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 1.2.0.0 to engine version 1.2.0.0 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 1.2.0.0 and above. See [Amazon Neptune parameter groups](parameter-groups.md) for more information.
Engine release 1.2.0.0 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`](cw-metrics.md#cw-metrics-UndoLogListSize) CloudWatch metric must fall to zero before any upgrade from a version earlier than 1.2.0.0 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 1.2.0.0 affecting earlier code that used the Bolt protocol with IAM authentication. Starting with release 1.2.0.0, 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](access-graph-opencypher-bolt.md) for examples.
## New Features in This Engine Release
+ Released the [Neptune data API](data-api.md).
The Amazon Neptune data API provides SDK support for loading data, running queries, getting information about your data, and running machine-learning operations. It supports the Gremlin and openCypher query languages in Neptune and is available in all SDK languages. It automatically signs API requests and greatly simplifies integrating Neptune into applications.
## Defects Fixed in This Engine Release
+ Fixed a Gremlin bug where adding an edge and its properties followed by `inV()` or `outV()` raised an `InternalFailureException`.
+ Fixed several issues with IAM role chaining that caused degraded bulk-loader performance in some cases.
## Query-Language Versions Supported in This Release
Before upgrading a DB cluster to version 1.2.1.0.R5, make sure that your project is compatible with these query-language versions:
+ *Gremlin earliest version supported:* `3.6.2`
+ *Gremlin latest version supported:* `3.6.2`
+ *openCypher version:* `Neptune-9.0.20190305-1.0`
+ *SPARQL version:* `1.1`
## Upgrading to This Release
Amazon Neptune 1.2.1.0.R5 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:
```
1. aws neptune modify-db-cluster \
2. --db-cluster-identifier (your-neptune-cluster) \
3. --engine-version 1.2.1.0 \
4. --apply-immediately
```
For Windows:
```
1. aws neptune modify-db-cluster ^
2. --db-cluster-identifier (your-neptune-cluster) ^
3. --engine-version 1.2.1.0 ^
4. --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.
**Note**
If you are trying to upgrade while [a pending action is in process](manage-console-maintaining), 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](cluster-maintenance.md). If you have any questions or concerns, the AWS Support team is available on the community forums and through [AWS Premium Support](http://aws.amazon.com/support).
# Amazon Neptune Engine Version 1.2.1.0.R4 (2023-08-10)
As of 2023-08-10, engine version 1.2.1.0.R4 is being generally deployed. Please note that it takes several days for a new release to become available in every region.
**Important**
Changes introduced in this engine release may in some cases cause you to observe degraded bulk load performance. As a result, upgrades to this release have been temporarily suspended until the problem has been resolved.
**Note**
**If upgrading from an engine version earlier than 1.2.0.0:**
[Engine release 1.2.0.0](engine-releases-1.2.0.0.md) 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 1.2.0.0 to engine version 1.2.0.0 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 1.2.0.0 and above. See [Amazon Neptune parameter groups](parameter-groups.md) for more information.
Engine release 1.2.0.0 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`](cw-metrics.md#cw-metrics-UndoLogListSize) CloudWatch metric must fall to zero before any upgrade from a version earlier than 1.2.0.0 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 1.2.0.0 affecting earlier code that used the Bolt protocol with IAM authentication. Starting with release 1.2.0.0, 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](access-graph-opencypher-bolt.md) for examples.
## Improvements in This Engine Release
+ Add [GraphSON-1.0](https://tinkerpop.apache.org/docs/3.4.1/dev/io/#graphson) support for Gremlin. To use GraphSON-1.0, pass `Accept header` with a value of:
```
application/vnd.gremlin-v1.0+json;types=false
```
## Defects Fixed in This Engine Release
+ Fixed a Gremlin bug where a transaction leak would occur when checking the Gremlin query status endpoint for queries with predicates in child traversals for steps that are not processed natively.
+ Fixed an openCypher bug in Bolt transaction handling.
+ Fixed a concurrency issue on the storage layer that could cause a crash.
+ Fixed a bug in slow query logs to make sure that they're not active when they're disabled.
## Query-Language Versions Supported in This Release
Before upgrading a DB cluster to version 1.2.1.0.R4, make sure that your project is compatible with these query-language versions:
+ *Gremlin earliest version supported:* `3.6.2`
+ *Gremlin latest version supported:* `3.6.5`
+ *openCypher version:* `Neptune-9.0.20190305-1.0`
+ *SPARQL version:* `1.1`
## Upgrade Paths to Engine Release 1.2.1.0.R4
## Upgrading to This Release
Amazon Neptune 1.2.1.0.R4 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:
```
1. aws neptune modify-db-cluster \
2. --db-cluster-identifier (your-neptune-cluster) \
3. --engine-version 1.2.1.0 \
4. --apply-immediately
```
For Windows:
```
1. aws neptune modify-db-cluster ^
2. --db-cluster-identifier (your-neptune-cluster) ^
3. --engine-version 1.2.1.0 ^
4. --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.
**Note**
If you are trying to upgrade while [a pending action is in process](manage-console-maintaining), 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](cluster-maintenance.md). If you have any questions or concerns, the AWS Support team is available on the community forums and through [AWS Premium Support](http://aws.amazon.com/support).
# Amazon Neptune Engine Version 1.2.1.0.R3 (2023-06-13)
As of 2023-06-13, engine version 1.2.1.0.R3 is being generally deployed. Please note that it takes several days for a new release to become available in every region.
**Important**
Changes introduced in this engine release may in some cases cause you to observe degraded bulk load performance. As a result, upgrades to this release have been temporarily suspended until the problem has been resolved.
**Note**
**If upgrading from an engine version earlier than 1.2.0.0:**
[Engine release 1.2.0.0](engine-releases-1.2.0.0.md) 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 1.2.0.0 to engine version 1.2.0.0 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 1.2.0.0 and above. See [Amazon Neptune parameter groups](parameter-groups.md) for more information.
Engine release 1.2.0.0 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`](cw-metrics.md#cw-metrics-UndoLogListSize) CloudWatch metric must fall to zero before any upgrade from a version earlier than 1.2.0.0 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 1.2.0.0 affecting earlier code that used the Bolt protocol with IAM authentication. Starting with release 1.2.0.0, 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](access-graph-opencypher-bolt.md) for examples.
## New Features in This Engine Release
+ Added support for cross-account bulk loading using [IAM role chaining](bulk-load-tutorial-chain-roles.md).
## Improvements in This Engine Release
+ Improved Gremlin's `fail()` step to differentiate the exception it produced from a generic `InternalFailureException` and to ensure that any user-supplied message provided to it was propagated back to the caller.
+ Improved Gremlin query engine optimizations for `store`, `aggregate`, `cap`, `limit`, and `hasLabel`.
+ Added support for openCypher trignometric functions:
+ `acos()`
+ `asin()`
+ `atan()`
+ `atan2()`
+ `cos()`
+ `cot()`
+ `degrees()`
+ `pi()`
+ `radians()`
+ `sin()`
+ `tan()`
+ Added support for several openCypher aggregating functions:
+ `percentileDisc()`
+ `stDev()`
+ Added support for openCypher `epochmillis()` function that converts a `datetime` to `epochmillis`. For example:
```
MATCH (n) RETURN epochMillis(n.someDateTime)
1698972364782
```
+ Added support for openCypher modulo (`%`) operator.
+ Added support for the openCypher Static Debug Explain tool.
+ Added support for the openCypher `randomUUID()` function.
+ Improved openCypher performance:
+ Improved the parser and query planner.
+ Improved CPU utilization in the DFE engine.
+ Improved the performance of queries containing multiple update clauses that reuse the same variables. Examples are:
```
MERGE (n {name: 'John'})
or
MERGE (m {name: 'Jim'})
or
MERGE (n)-[:knows {since: 2023}]→(m)
```
+ Optimized query plans for multi-hop query patterns such as:
```
MATCH (n)-->()-->()-->(m)
RETURN n m
```
+ Improved the performance of list and map injection through parameterized queries. For example:
```
UNWIND $idList as id MATCH (n {`~id`: id})
RETURN n.name
```
+ Improved query execution containing `WITH` by making it an appropriate barrier.
+ Optimized to avoid redundant materialization of values in `Unfold` and aggregation functions.
+ Improved the performance of SPARQL queries that contain a large number of static inputs in the `VALUES` clause, such as:
```
SELECT ?n WHERE { VALUES (?name) { ("John") ("Jim") ... many values ... } ?n a ?n_type . ?n ?name . }
```
+ Improved SPARQL CBD query performance.
## Defects Fixed in This Engine Release
+ Fixed a Gremlin bug where long queries with deep nesting were causing high CPU usage and query timeouts during the query planning phase.
+ Fixed a Gremlin bug where an invalid `NullPointerException` could be thrown when using `mergeV` or `mergeE`.
## Query-Language Versions Supported in This Release
Before upgrading a DB cluster to version 1.2.1.0.R3, make sure that your project is compatible with these query-language versions:
+ *Gremlin earliest version supported:* `3.6.2`
+ *Gremlin latest version supported:* `3.6.2`
+ *openCypher version:* `Neptune-9.0.20190305-1.0`
+ *SPARQL version:* `1.1`
## Upgrade Paths to Engine Release 1.2.1.0.R3
## Upgrading to This Release
Amazon Neptune 1.2.1.0.R3 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:
```
1. aws neptune modify-db-cluster \
2. --db-cluster-identifier (your-neptune-cluster) \
3. --engine-version 1.2.1.0 \
4. --apply-immediately
```
For Windows:
```
1. aws neptune modify-db-cluster ^
2. --db-cluster-identifier (your-neptune-cluster) ^
3. --engine-version 1.2.1.0 ^
4. --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.
**Note**
If you are trying to upgrade while [a pending action is in process](manage-console-maintaining), 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](cluster-maintenance.md). If you have any questions or concerns, the AWS Support team is available on the community forums and through [AWS Premium Support](http://aws.amazon.com/support).
# Amazon Neptune Engine Version 1.2.1.0.R2 (2023-05-02)
As of 2023-05-02, engine version 1.2.1.0.R2 is being generally deployed. Please note that it takes several days for a new release to become available in every region.
**Note**
**If upgrading from an engine version earlier than 1.2.0.0:**
[Engine release 1.2.0.0](engine-releases-1.2.0.0.md) 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 1.2.0.0 to engine version 1.2.0.0 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 1.2.0.0 and above. See [Amazon Neptune parameter groups](parameter-groups.md) for more information.
Engine release 1.2.0.0 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`](cw-metrics.md#cw-metrics-UndoLogListSize) CloudWatch metric must fall to zero before any upgrade from a version earlier than 1.2.0.0 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 1.2.0.0 affecting earlier code that used the Bolt protocol with IAM authentication. Starting with release 1.2.0.0, 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](access-graph-opencypher-bolt.md) for examples.
## Improvements in This Engine Release
+ Added an `enableInterContainerTrafficEncryption` parameter to all [Neptune ML APIs](machine-learning-api-reference.md), that you can use to enable and disable inter-container traffic encryption in training or hyper-parameter tuning jobs.
+ Added multi-label support for Gremlin `mergeV()` and `mergeE()`.
## Defects Fixed in This Engine Release
+ Fixed an openCypher bug where update and return queries did not handle `orderBy`, `limit`, or `skip` properly.
+ Fixed an openCypher bug that allowed parameters contained in one request to be overridden by parameters contained in another simultaneous request.
+ Fixed an openCypher bug where slow query logs did not contain correct query times.
+ Fixed a Gremlin bug where a transaction leak could occur when a query containing `GroupCountStep` was submitted as a string.
+ Fixed a Gremlin bug where WebSocket queries were failing when slow query logs were enabled.
+ Fixed a Gremlin bug where storage-counter debug logs were missing in the slow query logs for WebSocket requests.
+ Fixed several Gremlin bugs involving `mergeV()` and `mergeE()`.
+ Fixed a SPARQL bug where named graph query costs were mis-estimated, leading to sub-optimal query plans and out-of-memory errors.
+ Fixed a bug that affected authorization for Gremlin and openCypher queries on an IAM-enabled cluster.
## Query-Language Versions Supported in This Release
Before upgrading a DB cluster to version 1.2.1.0.R2, make sure that your project is compatible with these query-language versions:
+ *Gremlin earliest version supported:* `3.6.2`
+ *Gremlin latest version supported:* `3.6.2`
+ *openCypher version:* `Neptune-9.0.20190305-1.0`
+ *SPARQL version:* `1.1`
## Upgrade Paths to Engine Release 1.2.1.0.R2
## Upgrading to This Release
Amazon Neptune 1.2.1.0.R2 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:
```
1. aws neptune modify-db-cluster \
2. --db-cluster-identifier (your-neptune-cluster) \
3. --engine-version 1.2.1.0 \
4. --apply-immediately
```
For Windows:
```
1. aws neptune modify-db-cluster ^
2. --db-cluster-identifier (your-neptune-cluster) ^
3. --engine-version 1.2.1.0 ^
4. --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.
**Note**
If you are trying to upgrade while [a pending action is in process](manage-console-maintaining), 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](cluster-maintenance.md). If you have any questions or concerns, the AWS Support team is available on the community forums and through [AWS Premium Support](http://aws.amazon.com/support).