# Neptune Best Practices Using openCypher and Bolt
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Follow these best practices when using the openCypher query language and Bolt protocol with Neptune. For information about using openCypher in Neptune, see [Accessing the Neptune Graph with openCypher](access-graph-opencypher.md).

**Topics**
+ [Create a new connection after failover](#best-practices-opencypher-renew-connection)
+ [Connection handling for long-lived applications](#best-practices-opencypher-long-connections)
+ [Connection handling for Amazon Lambda](#best-practices-opencypher-lambda-connections)
+ [Prefer directed to bi-directional edges in queries](best-practices-opencypher-directed-edges.md)
+ [Neptune does not support multiple concurrent queries in a transaction](best-practices-opencypher-multiple-queries.md)
+ [Close driver objects when you're done](best-practices-opencypher-close-driver.md)
+ [Use explicit transaction modes for reading and writing](best-practices-opencypher-use-explicit-txs.md)
+ [Retry logic for exceptions](best-practices-opencypher-retry-logic.md)
+ [Set multiple properties at once using a single SET clause](best-practices-content-0.md)
+ [Use parameterized queries](best-practices-content-2.md)
+ [Use flattened maps instead of nested maps in UNWIND clause](best-practices-content-3.md)
+ [Place more restrictive nodes on the left side in Variable-Length Path (VLP) expressions](best-practices-content-4.md)
+ [Avoid redundant node label checks by using granular relationship names](best-practices-content-5.md)
+ [Specify edge labels where possible](best-practices-content-6.md)
+ [Avoid using the WITH clause when possible](best-practices-content-7.md)
+ [Place restrictive filters as early in the query as possible](best-practices-content-8.md)
+ [Explicitly check whether properties exist](best-practices-content-9.md)
+ [Do not use named path (unless it is required)](best-practices-content-10.md)
+ [Avoid COLLECT(DISTINCT())](best-practices-content-11.md)
+ [Prefer the properties function over individual property lookup when retrieving all property values](best-practices-content-12.md)
+ [Perform static computations outside of the query](best-practices-content-13.md)
+ [Batch inputs using UNWIND instead of individual statements](best-practices-content-14.md)
+ [Prefer using custom IDs for node/relationship](best-practices-content-15.md)
+ [Avoid doing \~id computations in the query](best-practices-content-16.md)
+ [Updating/Merging multiple nodes](best-practices-merge-multiple-nodes.md)

## Create a new connection after failover
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In case of a failover, the Bolt driver can continue connecting to the old writer instance rather than the new active one, because the DNS name resolved to a specific IP address.

To prevent this, close and then reconnect the `Driver` object after any failover.

## Connection handling for long-lived applications
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When building long-lived applications, such as those running within containers or on Amazon EC2 instances, instantiate a `Driver` object once and then reuse that object for the lifetime of the application. The `Driver` object is thread safe, and the overhead of initializing it is considerable.

## Connection handling for Amazon Lambda
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Bolt drivers are not recommended for use within Amazon Lambda functions, because of their connection overhead and management requirements. Use the [HTTPS endpoint](access-graph-opencypher-queries.md) instead.