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retry-request
Advanced tools
The retry-request npm package is designed to make it easier to handle network requests that might need to be retried due to failures or errors. It wraps around the standard request functionality, providing a way to automatically retry requests a specified number of times, with customizable intervals between retries. This is particularly useful in environments where network reliability can't always be guaranteed, or when dealing with services that might occasionally fail or be temporarily unavailable.
Basic retry functionality
This demonstrates how to use retry-request to make a simple HTTP request with retry functionality. If the request fails, retry-request will automatically retry the request based on its default configuration.
const retryRequest = require('retry-request');
const requestOptions = {
url: 'http://example.com'
};
retryRequest(requestOptions, function(err, response, body) {
if (!err) {
console.log(body);
}
});
Custom retry options
This example shows how to customize the retry behavior, including the number of retries, the delay between retries, and even specifying a custom request module to use for the actual HTTP requests.
const retryRequest = require('retry-request');
const requestOptions = {
url: 'http://example.com'
};
const options = {
retries: 5,
request: require('request'),
retryDelay: 1000
};
retryRequest(requestOptions, options, function(err, response, body) {
if (!err) {
console.log(body);
}
});
axios-retry is a package that adds retry functionality to Axios requests. It is similar to retry-request but is specifically designed for use with Axios, a promise-based HTTP client, offering more modern syntax and promise support compared to the callback-based retry-request.
got is a more comprehensive HTTP request library that includes built-in retry functionality among many other features. Unlike retry-request, which is a wrapper around the request library, got is a standalone library offering a wide range of HTTP capabilities, including retries, which makes it a more versatile choice for complex applications.
superagent-retry extends the superagent library with retry capabilities. It is similar to retry-request in that it adds retry functionality to an existing HTTP request library, but it is tailored for superagent users. This package is a good choice for those already using superagent and looking to add simple retry mechanisms.
Retry a request with built-in exponential backoff. |
$ npm install --save request
$ npm install --save retry-request
var request = require('retry-request', {
request: require('request')
});
It should work the same as request
in both callback mode and stream mode.
Note: This module only works when used as a readable stream, i.e. POST requests aren't supported (#3).
request
?Yes! You must independently install request
and provide it to this library:
var request = require('retry-request', {
request: require('request')
});
The code will actually look for the request
module automatically to save you this step. But, being explicit like in the example is also welcome.
urlThatReturns503
will be requested 3 total times before giving up and executing the callback.
request(urlThatReturns503, function (err, resp, body) {});
urlThatReturns503
will be requested 3 total times before giving up and emitting the response
and complete
event as usual.
request(urlThatReturns503)
.on('error', function () {})
.on('response', function () {})
.on('complete', function () {});
Yes! This project uses debug to provide the current retry attempt, each response status, and the delay computed until the next retry attempt is made. To enable the debug mode, set the environment variable DEBUG
to retry-request.
(Thanks for the implementation, @yihaozhadan!)
Passed directly to request
. See the list of options supported: https://github.com/request/request/#requestoptions-callback.
opts.noResponseRetries
Type: Number
Default: 2
The number of times to retry after a response fails to come through, such as a DNS resolution error or a socket hangup.
var opts = {
noResponseRetries: 0
};
request(url, opts, function (err, resp, body) {
// url was requested 1 time before giving up and
// executing this callback.
});
opts.objectMode
Type: Boolean
Default: false
Set to true
if your custom opts.request
function returns a stream in object mode.
opts.retries
Type: Number
Default: 2
var opts = {
retries: 4
};
request(urlThatReturns503, opts, function (err, resp, body) {
// urlThatReturns503 was requested a total of 5 times
// before giving up and executing this callback.
});
opts.currentRetryAttempt
Type: Number
Default: 0
var opts = {
currentRetryAttempt: 1
};
request(urlThatReturns503, opts, function (err, resp, body) {
// urlThatReturns503 was requested as if it already failed once.
});
opts.shouldRetryFn
Type: Function
Default: Returns true
if http.incomingMessage.statusCode is < 200 or >= 400.
var opts = {
shouldRetryFn: function (incomingHttpMessage) {
return incomingHttpMessage.statusMessage !== 'OK';
}
};
request(urlThatReturnsNonOKStatusMessage, opts, function (err, resp, body) {
// urlThatReturnsNonOKStatusMessage was requested a
// total of 3 times, each time using `opts.shouldRetryFn`
// to decide if it should continue before giving up and
// executing this callback.
});
opts.request
Type: Function
Default: try { require('request') }
If we cannot locate request
, we will throw an error advising you to provide it explicitly.
NOTE: If you override the request function, and it returns a stream in object mode, be sure to set opts.objectMode
to true
.
var originalRequest = require('request').defaults({
pool: {
maxSockets: Infinity
}
});
var opts = {
request: originalRequest
};
request(urlThatReturns503, opts, function (err, resp, body) {
// Your provided `originalRequest` instance was used.
});
opts.maxRetryDelay
Type: Number
Default: 64
The maximum time to delay in seconds. If retryDelayMultiplier results in a delay greater than maxRetryDelay, retries should delay by maxRetryDelay seconds instead.
opts.retryDelayMultiplier
Type: Number
Default: 2
The multiplier by which to increase the delay time between the completion of failed requests, and the initiation of the subsequent retrying request.
opts.totalTimeout
Type: Number
Default: 600
The length of time to keep retrying in seconds. The last sleep period will be shortened as necessary, so that the last retry runs at deadline (and not considerably beyond it). The total time starting from when the initial request is sent, after which an error will be returned, regardless of the retrying attempts made meanwhile.
Passed directly to request
. See the callback section: https://github.com/request/request/#requestoptions-callback.
FAQs
Retry a request.
We found that retry-request demonstrated a healthy version release cadence and project activity because the last version was released less than a year ago. It has 2 open source maintainers collaborating on the project.
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