A utility that allows retrying a function with an exponential delay between attempts.
npm install exponential-backoffA utility that allows retrying a function with an exponential delay between attempts.
``
npm i exponential-backoff
The backOff function takes a promise-returning function to retry, and an optional BackOffOptions object. It returns a Promise.
`ts`
function backOff
request: () => Promise
options?: BackOffOptions
): Promise
Here is an example retrying a function that calls a hypothetical weather endpoint:
`js
import { backOff } from "exponential-backoff";
function getWeather() {
return fetch("weather-endpoint");
}
async function main() {
try {
const response = await backOff(() => getWeather());
// process response
} catch (e) {
// handle error
}
}
main();
`
Migrating across major versions? Here are our breaking changes.
- delayFirstAttempt?: boolean
Decides whether the startingDelay should be applied before the first call. If false, the first call will occur without a delay.
Default value is false.
- jitter?: JitterType | string
Decides whether a jitter should be applied to the delay. Possible values are full and none.
Default value is none.
- maxDelay?: number
The maximum delay, in milliseconds, between two consecutive attempts.
Default value is Infinity.
- numOfAttempts?: number
The maximum number of times to attempt the function.
Default value is 10.
Minimum value is 1.
- retry?: (e: any, attemptNumber: number) => boolean | Promise
The retry function can be used to run logic after every failed attempt (e.g. logging a message, assessing the last error, etc.). It is called with the last error and the upcoming attempt number. Returning true will retry the function as long as the numOfAttempts has not been exceeded. Returning false will end the execution.
Default value is a function that always returns true.
- startingDelay?: number
The delay, in milliseconds, before executing the function for the first time.
Default value is 100 ms.
- timeMultiple?: number
The startingDelay is multiplied by the timeMultiple to increase the delay between reattempts.
Default value is 2`.