feat: add support for retry-after header

nodejs · Oct 25, 2023 · b8fbef0 · b8fbef0
1 parent 0fc9518
commit b8fbef0
Show file tree

Hide file tree

Showing 2 changed files with 564 additions and 253 deletions.
diff --git a/lib/handler/RetryHandler.js b/lib/handler/RetryHandler.js
@@ -9,6 +9,13 @@ const {
   safeHTTPMethods
 } = require('../core/util')
 
+function calculateRetryAfterHeader (retryAfter) {
+  const current = Date.now()
+  const diff = new Date(retryAfter).getTime() - current
+
+  return diff
+}
+
 class RetryHandler {
   constructor (opts, handlers, retryOpts) {
     const {
@@ -22,6 +29,7 @@ class RetryHandler {
       methods,
       idempotent,
       codes,
+      retryAfter,
       status: statusCodes
     } = retryOpts ?? {}
 
@@ -32,6 +40,7 @@ class RetryHandler {
     this.aborted = false
     this.retryOpts = {
       retry: retryFn ?? RetryHandler[kRetryHandlerDefaultRetry],
+      retryAfter: retryAfter ?? true,
       maxTimeout: maxTimeout ?? 30 * 1000, // 30s,
       timeout: minTimeout ?? 500, // .5s
       timeoutFactor: timeoutFactor ?? 2,
@@ -41,7 +50,7 @@ class RetryHandler {
       // States weather or not retry on idempotent methods
       idempotent: idempotent ?? false,
       // Indicates which errors to retry
-      status: statusCodes ?? [500, 502, 503, 504],
+      status: statusCodes ?? [500, 502, 503, 504, 429],
       // List of errors to retry
       codes: codes ?? [
         'ECONNRESET',
@@ -88,10 +97,11 @@ class RetryHandler {
   }
 
   static [kRetryHandlerDefaultRetry] (err, { counter, currentTimeout }, opts) {
-    const { statusCode, code } = err
+    const { statusCode, code, headers } = err
     const { method } = opts
     const {
       max,
+      timeout,
       maxTimeout,
       timeoutFactor,
       status,
@@ -100,6 +110,9 @@ class RetryHandler {
       methods
     } = opts.retry
 
+    currentTimeout =
+      currentTimeout != null && currentTimeout > 0 ? currentTimeout : timeout
+
     // Any code that is not a Undici's originated and allowed to retry
     if (
       code &&
@@ -128,10 +141,18 @@ class RetryHandler {
     // If we reached the max number of retries
     if (counter > max) return null
 
-    const retryTimeout = Math.min(
-      currentTimeout * timeoutFactor ** counter,
-      maxTimeout
-    )
+    let retryAfterHeader = headers != null && headers['retry-after']
+    if (retryAfterHeader) {
+      retryAfterHeader = Number(retryAfterHeader)
+      retryAfterHeader = isNaN(retryAfterHeader)
+        ? calculateRetryAfterHeader(retryAfterHeader)
+        : retryAfterHeader * 1e3 // Retry-After is in seconds
+    }
+
+    const retryTimeout =
+      retryAfterHeader > 0
+        ? Math.min(retryAfterHeader, maxTimeout)
+        : Math.min(currentTimeout * timeoutFactor ** counter, maxTimeout)
 
     return retryTimeout
   }