Retried

Abstraction for exponential and custom retry strategies for failed operations. This module is a Deno/ES6+/TypeScript rewrite of the popular retry nodejs module

Example

The example below will retry a potentially failing fetch operation 10 times using an exponential backoff strategy. With the default settings, this means the last attempt is made after 17 minutes and 3 seconds .

import * as retried from 'https://deno.land/x/[email protected]/mod.ts'

function faultTolerantFetch(address: string): Promise<Response> {
    return new Promise((resolve, reject) => {
        const operation = retried.operation({})
        operation.attempt(async (currentAttempt: number) => {
            try {
                resolve(await fetch(address))
                operation.succeed()
            } catch (error) {
                console.error(`Attempt ${currentAttempt}, Error:`)
                console.error(error)

                if (await operation.retry(error)) return
                reject(error)
            }
        })
    })
}

try {
    const response = await faultTolerantFetch('http://example.com')
    const body = await response.text()
    console.log(body)
} catch (e) {
    console.error("Fetch failed: ")
    console.error(e)
}

You can also configure the factors that go into the exponential backoff. See the API documentation below for all available settings.

const operation = retry.operation({
    retries: 5,
    factor: 3,
    minTimeout: 1 * 1000,
    maxTimeout: 60 * 1000,
    randomize: true,
})

API

See:

• https://doc.deno.land/https/deno.land/x/[email protected]/lib/retried.ts and
• https://doc.deno.land/https/deno.land/x/[email protected]/lib/retryOperation.ts

License

Retried is licensed under the MIT license. Code is adapted from https://github.com/tim-kos/node-retry (also under the MIT license)