3.8 KiB
3.8 KiB
Class: RetryHandler
Extends: undici.DispatcherHandlers
A handler class that implements the retry logic for a request.
new RetryHandler(dispatchOptions, retryHandlers, [retryOptions])
Arguments:
- options
Dispatch.DispatchOptions & RetryOptions
(required) - It is an intersection ofDispatcher.DispatchOptions
andRetryOptions
. - retryHandlers
RetryHandlers
(required) - Object containing thedispatch
to be used on every retry, andhandler
for handling thedispatch
lifecycle.
Returns: retryHandler
Parameter: Dispatch.DispatchOptions & RetryOptions
Extends: Dispatch.DispatchOptions
.
RetryOptions
- retry
(err: Error, context: RetryContext, callback: (err?: Error | null) => void) => void
(optional) - Function to be called after every retry. It should pass error if no more retries should be performed. - maxRetries
number
(optional) - Maximum number of retries. Default:5
- maxTimeout
number
(optional) - Maximum number of milliseconds to wait before retrying. Default:30000
(30 seconds) - minTimeout
number
(optional) - Minimum number of milliseconds to wait before retrying. Default:500
(half a second) - timeoutFactor
number
(optional) - Factor to multiply the timeout by for each retry attempt. Default:2
- retryAfter
boolean
(optional) - It enables automatic retry after theRetry-After
header is received. Default:true
- methods
string[]
(optional) - Array of HTTP methods to retry. Default:['GET', 'PUT', 'HEAD', 'OPTIONS', 'DELETE']
- statusCodes
number[]
(optional) - Array of HTTP status codes to retry. Default:[429, 500, 502, 503, 504]
- errorCodes
string[]
(optional) - Array of Error codes to retry. Default: `['ECONNRESET', 'ECONNREFUSED', 'ENOTFOUND', 'ENETDOWN','ENETUNREACH', 'EHOSTDOWN',
RetryContext
state
:RetryState
- Current retry state. It can be mutated.opts
:Dispatch.DispatchOptions & RetryOptions
- Options passed to the retry handler.
Parameter RetryHandlers
- dispatch
(options: Dispatch.DispatchOptions, handlers: Dispatch.DispatchHandlers) => Promise<Dispatch.DispatchResponse>
(required) - Dispatch function to be called after every retry. - handler Extends
Dispatch.DispatchHandlers
(required) - Handler function to be called after the request is successful or the retries are exhausted.
Examples:
const client = new Client(`http://localhost:${server.address().port}`);
const chunks = [];
const handler = new RetryHandler(
{
...dispatchOptions,
retryOptions: {
// custom retry function
retry: function (err, state, callback) {
counter++;
if (err.code && err.code === "UND_ERR_DESTROYED") {
callback(err);
return;
}
if (err.statusCode === 206) {
callback(err);
return;
}
setTimeout(() => callback(null), 1000);
},
},
},
{
dispatch: (...args) => {
return client.dispatch(...args);
},
handler: {
onConnect() {},
onBodySent() {},
onHeaders(status, _rawHeaders, resume, _statusMessage) {
// do something with headers
},
onData(chunk) {
chunks.push(chunk);
return true;
},
onComplete() {},
onError() {
// handle error properly
},
},
}
);
Example - Basic RetryHandler with defaults
const client = new Client(`http://localhost:${server.address().port}`);
const handler = new RetryHandler(dispatchOptions, {
dispatch: client.dispatch.bind(client),
handler: {
onConnect() {},
onBodySent() {},
onHeaders(status, _rawHeaders, resume, _statusMessage) {},
onData(chunk) {},
onComplete() {},
onError(err) {},
},
});