feat(ratelimit): Add metrics rate limit

packages/core/src/transports/base.ts

@@ -49,10 +49,10 @@ export function createTransport(
 
     // Drop rate limited items from envelope
     forEachEnvelopeItem(envelope, (item, type) => {
-      const envelopeItemDataCategory = envelopeItemTypeToDataCategory(type);
-      if (isRateLimited(rateLimits, envelopeItemDataCategory)) {
+      const dataCategory = envelopeItemTypeToDataCategory(type);
+      if (isRateLimited(rateLimits, dataCategory)) {
         const event: Event | undefined = getEventForEnvelopeItem(item, type);
-        options.recordDroppedEvent('ratelimit_backoff', envelopeItemDataCategory, event);
+        options.recordDroppedEvent('ratelimit_backoff', dataCategory, event);
       } else {
         filteredEnvelopeItems.push(item);
       }

packages/types/src/datacategory.ts

@@ -1,7 +1,7 @@
 // This type is used in various places like Client Reports and Rate Limit Categories
 // See:
 // - https://develop.sentry.dev/sdk/rate-limiting/#definitions
-// - https://github.com/getsentry/relay/blob/c3b339e151c1e548ede489a01c65db82472c8751/relay-common/src/constants.rs#L139-L152
+// - https://github.com/getsentry/relay/blob/ec791fed9c2260688f25ea6a6d53ab913927e9a5/relay-base-schema/src/data_category.rs#L91
 // - https://develop.sentry.dev/sdk/client-reports/#envelope-item-payload under `discarded_events`
 export type DataCategory =
   // Reserved and only used in edgecases, unlikely to be ever actually used
@@ -26,8 +26,8 @@ export type DataCategory =
   | 'monitor'
   // Feedback type event (v2)
   | 'feedback'
-  // Statsd type event for metrics
-  | 'statsd'
+  // Metrics sent via the statsd or metrics envelope items
+  | 'metric_bucket'
   // Span
   | 'span'
   // Unknown data category

packages/types/src/envelope.ts

@@ -24,6 +24,8 @@ export type DynamicSamplingContext = {
   sampled?: string;
 };
 
+// https://github.com/getsentry/relay/blob/311b237cd4471042352fa45e7a0824b8995f216f/relay-server/src/envelope.rs#L154
+// https://develop.sentry.dev/sdk/envelopes/#data-model
 export type EnvelopeItemType =
   | 'client_report'
   | 'user_report'

packages/utils/src/envelope.ts

@@ -209,8 +209,7 @@ const ITEM_TYPE_TO_DATA_CATEGORY_MAP: Record<EnvelopeItemType, DataCategory> = {
   check_in: 'monitor',
   feedback: 'feedback',
   span: 'span',
-  // TODO: This is a temporary workaround until we have a proper data category for metrics
-  statsd: 'unknown',
+  statsd: 'metric_bucket',
 };
 
 /**
@@ -220,7 +219,7 @@ export function envelopeItemTypeToDataCategory(type: EnvelopeItemType): DataCate
   return ITEM_TYPE_TO_DATA_CATEGORY_MAP[type];
 }
 
-/** Extracts the minimal SDK info from from the metadata or an events */
+/** Extracts the minimal SDK info from the metadata or an events */
 export function getSdkMetadataForEnvelopeHeader(metadataOrEvent?: SdkMetadata | Event): SdkInfo | undefined {
   if (!metadataOrEvent || !metadataOrEvent.sdk) {
     return;

packages/utils/src/ratelimit.ts

@@ -1,4 +1,4 @@
-import type { TransportMakeRequestResponse } from '@sentry/types';
+import type { DataCategory, TransportMakeRequestResponse } from '@sentry/types';
 
 // Intentionally keeping the key broad, as we don't know for sure what rate limit headers get returned from backend
 export type RateLimits = Record<string, number>;
@@ -32,15 +32,15 @@ export function parseRetryAfterHeader(header: string, now: number = Date.now()):
  *
  * @return the time in ms that the category is disabled until or 0 if there's no active rate limit.
  */
-export function disabledUntil(limits: RateLimits, category: string): number {
-  return limits[category] || limits.all || 0;
+export function disabledUntil(limits: RateLimits, dataCategory: DataCategory): number {
+  return limits[dataCategory] || limits.all || 0;
 }
 
 /**
  * Checks if a category is rate limited
  */
-export function isRateLimited(limits: RateLimits, category: string, now: number = Date.now()): boolean {
-  return disabledUntil(limits, category) > now;
+export function isRateLimited(limits: RateLimits, dataCategory: DataCategory, now: number = Date.now()): boolean {
+  return disabledUntil(limits, dataCategory) > now;
 }
 
 /**
@@ -67,23 +67,32 @@ export function updateRateLimits(
      * rate limit headers are of the form
      *     <header>,<header>,..
      * where each <header> is of the form
-     *     <retry_after>: <categories>: <scope>: <reason_code>
+     *     <retry_after>: <categories>: <scope>: <reason_code>: <namespaces>
      * where
      *     <retry_after> is a delay in seconds
      *     <categories> is the event type(s) (error, transaction, etc) being rate limited and is of the form
      *         <category>;<category>;...
      *     <scope> is what's being limited (org, project, or key) - ignored by SDK
      *     <reason_code> is an arbitrary string like "org_quota" - ignored by SDK
+     *     <namespaces> Semicolon-separated list of metric namespace identifiers. Defines which namespace(s) will be affected.
+     *         Only present if rate limit applies to the metric_bucket data category.
      */
     for (const limit of rateLimitHeader.trim().split(',')) {
-      const [retryAfter, categories] = limit.split(':', 2);
+      const [retryAfter, categories, , , namespaces] = limit.split(':', 5);
       const headerDelay = parseInt(retryAfter, 10);
       const delay = (!isNaN(headerDelay) ? headerDelay : 60) * 1000; // 60sec default
       if (!categories) {
         updatedRateLimits.all = now + delay;
       } else {
         for (const category of categories.split(';')) {
-          updatedRateLimits[category] = now + delay;
+          if (category === 'metric_bucket') {
+            // namespaces will be present when category === 'metric_bucket'
+            if (!namespaces || namespaces.split(';').includes('custom')) {
+              updatedRateLimits[category] = now + delay;
+            }
+          } else {
+            updatedRateLimits[category] = now + delay;
+          }
         }
       }
     }

packages/utils/test/ratelimit.test.ts

@@ -197,3 +197,43 @@ describe('updateRateLimits()', () => {
     expect(updatedRateLimits.all).toEqual(60_000);
   });
 });
+
+describe('data category "metric_bucket"', () => {
+  test('should add limit for `metric_bucket` category when namespaces contain "custom"', () => {
+    const rateLimits: RateLimits = {};
+    const headers = {
+      'retry-after': null,
+      'x-sentry-rate-limits': '42:metric_bucket:::custom',
+    };
+    const updatedRateLimits = updateRateLimits(rateLimits, { headers }, 0);
+    expect(updatedRateLimits.metric_bucket).toEqual(42 * 1000);
+  });
+
+  test('should not add limit for `metric_bucket` category when namespaces do not contain "custom"', () => {
+    const rateLimits: RateLimits = {};
+    const headers = {
+      'retry-after': null,
+      'x-sentry-rate-limits': '42:metric_bucket:::namespace1;namespace2',
+    };
+    const updatedRateLimits = updateRateLimits(rateLimits, { headers }, 0);
+    expect(updatedRateLimits.metric_bucket).toBeUndefined();
+  });
+
+  test('should add limit for `metric_bucket` category when namespaces are empty', () => {
+    const rateLimits: RateLimits = {};
+
+    const headers1 = {
+      'retry-after': null,
+      'x-sentry-rate-limits': '42:metric_bucket', // without semicolon at the end
+    };
+    const updatedRateLimits1 = updateRateLimits(rateLimits, { headers: headers1 }, 0);
+    expect(updatedRateLimits1.metric_bucket).toEqual(42 * 1000);
+
+    const headers2 = {
+      'retry-after': null,
+      'x-sentry-rate-limits': '42:metric_bucket:organization:quota_exceeded:', // with semicolon at the end
+    };
+    const updatedRateLimits2 = updateRateLimits(rateLimits, { headers: headers2 }, 0);
+    expect(updatedRateLimits2.metric_bucket).toEqual(42 * 1000);
+  });
+});