neo4j-retried

Retry queries run against the neo4j driver. Great for handling deadlock exceptions.

Important caveat

The retried wrapper only works if you use neo4j-driver with promises, it does not handle the .subscribe() way.

Installation

npm install --save @ambassify/neo4j-retried

Example

Automatically retry DeadlockDetected exceptions.

const neo4j = require('neo4j-driver').v1;
const neo4jRetried = require('@ambassify/neo4j-retried');

const driver = neo4jRetried(neo4j.driver(/* your driver config */), {
    shouldRetry: [ neo4jRetried.errors.Transaction.DeadlockDetected ]
});
const session = driver.session();

session.run('CREATE CONSTRAINT ON (p:Person) ASSERT p.name IS UNIQUE')
.catch(e => {
    console.log(e);
    session.close();
    driver.close();
});

Options

retries

The amount of times a query should be retried.

delay

The delay between retries, can be an integer or a function.

In case of integer, the value is used as slot time in a binary exponential backoff algorithm (https://en.wikipedia.org/wiki/Exponential_backoff)

In case of a function, the function is called with the total amount of previous calls as first parameter and should return the delay in ms.

shouldRetry

Decides whether or not a failure should be retried. Can be an array of Neo4j error codes that should be retried or a function that accepts the error that occurred and returns a boolean.

Contribute

We really appreciate any contribution you would like to make, so don't hesitate to report issues or submit pull requests.

License

This project is released under a MIT license.

About us

If you would like to know more about us, be sure to have a look at our website, or our Twitter accounts Ambassify, Sitebase, JorgenEvens