import { retry } from "https://deno.land/std@0.218.2/async/mod.ts";
Calls the given (possibly asynchronous) function up to maxAttempts
times.
Retries as long as the given function throws. If the attempts are exhausted,
throws a RetryError
with cause
set to the inner exception.
The backoff is calculated by multiplying minTimeout
with multiplier
to the power of the current attempt counter (starting at 0 up to maxAttempts - 1
). It is capped at maxTimeout
however.
How long the actual delay is, depends on jitter
.
When jitter
is the default value of 1
, waits between two attempts for a
randomized amount between 0 and the backoff time. With the default options
the maximal delay will be 15s = 1s + 2s + 4s + 8s
. If all five attempts
are exhausted the mean delay will be 9.5s = ½(4s + 15s)
.
When jitter
is 0
, waits the full backoff time.
Examples
Example 1
Example 1
import { retry } from "https://deno.land/std@0.218.2/async/retry.ts";
const req = async () => {
// some function that throws sometimes
};
// Below resolves to the first non-error result of `req`
const retryPromise = await retry(req, {
multiplier: 2,
maxTimeout: 60000,
maxAttempts: 5,
minTimeout: 100,
jitter: 1,
});
Example 2
Example 2
import { retry } from "https://deno.land/std@0.218.2/async/retry.ts";
const req = async () => {
// some function that throws sometimes
};
// Make sure we wait at least 1 minute, but at most 2 minutes
const retryPromise = await retry(req, {
multiplier: 2.34,
maxTimeout: 80000,
maxAttempts: 7,
minTimeout: 1000,
jitter: 0.5,
});