Rate limit served:X events

packages/backend-core/src/cache/generic.js

@@ -9,6 +9,7 @@ exports.CacheKeys = {
   UNIQUE_TENANT_ID: "uniqueTenantId",
   EVENTS: "events",
   BACKFILL_METADATA: "backfillMetadata",
+  EVENTS_RATE_LIMIT: "eventsRateLimit",
 }
 
 exports.TTL = {

packages/backend-core/src/events/processors/AnalyticsProcessor.ts

@@ -2,7 +2,7 @@ import { Event, Identity, Group, IdentityType } from "@budibase/types"
 import { EventProcessor } from "./types"
 import env from "../../environment"
 import * as analytics from "../analytics"
-import PosthogProcessor from "./PosthogProcessor"
+import PosthogProcessor from "./posthog"
 
 /**
  * Events that are always captured.

packages/backend-core/src/events/processors/PosthogProcessor.ts → packages/backend-core/src/events/processors/posthog/PosthogProcessor.ts

@@ -1,9 +1,10 @@
 import PostHog from "posthog-node"
 import { Event, Identity, Group, BaseEvent } from "@budibase/types"
-import { EventProcessor } from "./types"
-import env from "../../environment"
-import * as context from "../../context"
-const pkg = require("../../../package.json")
+import { EventProcessor } from "../types"
+import env from "../../../environment"
+import * as context from "../../../context"
+import * as rateLimiting from "./rateLimiting"
+const pkg = require("../../../../package.json")
 
 const EXCLUDED_EVENTS: Event[] = [
   Event.USER_UPDATED,
@@ -42,6 +43,10 @@ export default class PosthogProcessor implements EventProcessor {
       return
     }
 
+    if (await rateLimiting.limited(event)) {
+      return
+    }
+
     properties.version = pkg.version
     properties.service = env.SERVICE
     properties.environment = identity.environment

packages/backend-core/src/events/processors/posthog/index.ts

@@ -0,0 +1,2 @@
+import PosthogProcessor from "./PosthogProcessor"
+export default PosthogProcessor

packages/backend-core/src/events/processors/posthog/rateLimiting.ts

@@ -0,0 +1,95 @@
+import { Event } from "@budibase/types"
+import { CacheKeys, TTL } from "../../../cache/generic"
+import * as cache from "../../../cache/generic"
+
+type RateLimitedEvent =
+  | Event.SERVED_BUILDER
+  | Event.SERVED_APP_PREVIEW
+  | Event.SERVED_APP
+
+const isRateLimited = (event: Event): event is RateLimitedEvent => {
+  return (
+    event === Event.SERVED_BUILDER ||
+    event === Event.SERVED_APP_PREVIEW ||
+    event === Event.SERVED_APP
+  )
+}
+
+interface EventProperties {
+  timestamp: number
+}
+
+enum RateLimit {
+  CALENDAR_DAY = "calendarDay",
+}
+
+const RATE_LIMITS = {
+  [Event.SERVED_APP]: RateLimit.CALENDAR_DAY,
+  [Event.SERVED_APP_PREVIEW]: RateLimit.CALENDAR_DAY,
+  [Event.SERVED_BUILDER]: RateLimit.CALENDAR_DAY,
+}
+
+/**
+ * Check if this event should be sent right now
+ * Return false to signal the event SHOULD be sent
+ * Return true to signal the event should NOT be sent
+ */
+export const limited = async (event: Event): Promise<boolean> => {
+  // not a rate limited event -- send
+  if (!isRateLimited(event)) {
+    return false
+  }
+
+  const cachedEvent = (await readEvent(event)) as EventProperties
+  if (cachedEvent) {
+    const timestamp = new Date(cachedEvent.timestamp)
+    const limit = RATE_LIMITS[event]
+    switch (limit) {
+      case RateLimit.CALENDAR_DAY: {
+        // get midnight at the start of the next day for the timestamp
+        timestamp.setDate(timestamp.getDate() + 1)
+        timestamp.setHours(0, 0, 0, 0)
+
+        // if we have passed the threshold into the next day
+        if (Date.now() > timestamp.getTime()) {
+          // update the timestamp in the event -- send
+          await recordEvent(event, { timestamp: Date.now() })
+          return false
+        } else {
+          // still within the limited period -- don't send
+          return true
+        }
+      }
+    }
+  } else {
+    // no event present i.e. expired -- send
+    await recordEvent(event, { timestamp: Date.now() })
+    return false
+  }
+}
+
+const eventKey = (event: RateLimitedEvent) => {
+  return `${CacheKeys.EVENTS_RATE_LIMIT}:${event}`
+}
+
+const readEvent = async (event: RateLimitedEvent) => {
+  const key = eventKey(event)
+  return cache.get(key)
+}
+
+const recordEvent = async (
+  event: RateLimitedEvent,
+  properties: EventProperties
+) => {
+  const key = `${CacheKeys.EVENTS_RATE_LIMIT}:${event}`
+
+  const limit = RATE_LIMITS[event]
+  let ttl
+  switch (limit) {
+    case RateLimit.CALENDAR_DAY: {
+      ttl = TTL.ONE_DAY
+    }
+  }
+
+  await cache.store(key, properties, ttl)
+}

packages/backend-core/src/events/processors/posthog/tests/PosthogProcessor.spec.ts

@@ -0,0 +1,96 @@
+import PosthogProcessor from "../PosthogProcessor"
+import { Event, IdentityType, Hosting } from "@budibase/types"
+const tk = require("timekeeper")
+import * as Cache from "../../../../cache/generic"
+
+const newIdentity = () => {
+  return {
+    id: "test",
+    type: IdentityType.USER,
+    hosting: Hosting.SELF,
+    environment: "test",
+  }
+}
+
+describe("PosthogProcessor", () => {
+  beforeEach(() => {
+    jest.clearAllMocks()
+  })
+
+  describe("processEvent", () => {
+    it("processes event", async () => {
+      const processor = new PosthogProcessor("test")
+
+      const identity = newIdentity()
+      const properties = {}
+
+      await processor.processEvent(Event.APP_CREATED, identity, properties)
+
+      expect(processor.posthog.capture).toHaveBeenCalledTimes(1)
+    })
+
+    it("honours exclusions", async () => {
+      const processor = new PosthogProcessor("test")
+
+      const identity = newIdentity()
+      const properties = {}
+
+      await processor.processEvent(Event.AUTH_SSO_UPDATED, identity, properties)
+      expect(processor.posthog.capture).toHaveBeenCalledTimes(0)
+    })
+
+    describe("rate limiting", () => {
+      it("sends daily event once in same day", async () => {
+        const processor = new PosthogProcessor("test")
+        const identity = newIdentity()
+        const properties = {}
+
+        tk.freeze(new Date(2022, 0, 1, 14, 0))
+        await processor.processEvent(Event.SERVED_BUILDER, identity, properties)
+        // go forward one hour
+        tk.freeze(new Date(2022, 0, 1, 15, 0))
+        await processor.processEvent(Event.SERVED_BUILDER, identity, properties)
+
+        expect(processor.posthog.capture).toHaveBeenCalledTimes(1)
+      })
+
+      it("sends daily event once per unique day", async () => {
+        const processor = new PosthogProcessor("test")
+        const identity = newIdentity()
+        const properties = {}
+
+        tk.freeze(new Date(2022, 0, 1, 14, 0))
+        await processor.processEvent(Event.SERVED_BUILDER, identity, properties)
+        // go forward into next day
+        tk.freeze(new Date(2022, 0, 2, 9, 0))
+        await processor.processEvent(Event.SERVED_BUILDER, identity, properties)
+        // go forward into next day
+        tk.freeze(new Date(2022, 0, 3, 5, 0))
+        await processor.processEvent(Event.SERVED_BUILDER, identity, properties)
+        // go forward one hour
+        tk.freeze(new Date(2022, 0, 3, 6, 0))
+        await processor.processEvent(Event.SERVED_BUILDER, identity, properties)
+
+        expect(processor.posthog.capture).toHaveBeenCalledTimes(4)
+      })
+
+      it("sends event again after cache expires", async () => {
+        const processor = new PosthogProcessor("test")
+        const identity = newIdentity()
+        const properties = {}
+
+        tk.freeze(new Date(2022, 0, 1, 14, 0))
+        await processor.processEvent(Event.SERVED_BUILDER, identity, properties)
+
+        await Cache.bustCache(
+          `${Cache.CacheKeys.EVENTS_RATE_LIMIT}:${Event.SERVED_BUILDER}`
+        )
+
+        tk.freeze(new Date(2022, 0, 1, 14, 0))
+        await processor.processEvent(Event.SERVED_BUILDER, identity, properties)
+
+        expect(processor.posthog.capture).toHaveBeenCalledTimes(2)
+      })
+    })
+  })
+})

packages/backend-core/src/events/processors/tests/PosthogProcessor.spec.ts

@@ -1,40 +0,0 @@
-import PosthogProcessor from "../PosthogProcessor"
-import { Event, IdentityType, Hosting } from "@budibase/types"
-
-const newIdentity = () => {
-  return {
-    id: "test",
-    type: IdentityType.USER,
-    hosting: Hosting.SELF,
-    environment: "test",
-  }
-}
-
-describe("PosthogProcessor", () => {
-  beforeEach(() => {
-    jest.clearAllMocks()
-  })
-
-  describe("processEvent", () => {
-    it("processes event", () => {
-      const processor = new PosthogProcessor("test")
-
-      const identity = newIdentity()
-      const properties = {}
-
-      processor.processEvent(Event.APP_CREATED, identity, properties)
-
-      expect(processor.posthog.capture).toHaveBeenCalledTimes(1)
-    })
-
-    it("honours exclusions", () => {
-      const processor = new PosthogProcessor("test")
-
-      const identity = newIdentity()
-      const properties = {}
-
-      processor.processEvent(Event.AUTH_SSO_UPDATED, identity, properties)
-      expect(processor.posthog.capture).toHaveBeenCalledTimes(0)
-    })
-  })
-})