[DI] Batch outgoing http requests

integration-tests/debugger/snapshot-pruning.spec.js

@@ -11,7 +11,7 @@ describe('Dynamic Instrumentation', function () {
       beforeEach(t.triggerBreakpoint)
 
       it('should prune snapshot if payload is too large', function (done) {
-        t.agent.on('debugger-input', ({ payload }) => {
+        t.agent.on('debugger-input', ({ payload: [payload] }) => {
           assert.isBelow(Buffer.byteLength(JSON.stringify(payload)), 1024 * 1024) // 1MB
           assert.deepEqual(payload['debugger.snapshot'].captures, {
             lines: {

integration-tests/debugger/snapshot.spec.js

@@ -11,7 +11,7 @@ describe('Dynamic Instrumentation', function () {
       beforeEach(t.triggerBreakpoint)
 
       it('should capture a snapshot', function (done) {
-        t.agent.on('debugger-input', ({ payload: { 'debugger.snapshot': { captures } } }) => {
+        t.agent.on('debugger-input', ({ payload: [{ 'debugger.snapshot': { captures } }] }) => {
           assert.deepEqual(Object.keys(captures), ['lines'])
           assert.deepEqual(Object.keys(captures.lines), [String(t.breakpoint.line)])
 
@@ -114,7 +114,7 @@ describe('Dynamic Instrumentation', function () {
       })
 
       it('should respect maxReferenceDepth', function (done) {
-        t.agent.on('debugger-input', ({ payload: { 'debugger.snapshot': { captures } } }) => {
+        t.agent.on('debugger-input', ({ payload: [{ 'debugger.snapshot': { captures } }] }) => {
           const { locals } = captures.lines[t.breakpoint.line]
           delete locals.request
           delete locals.fastify
@@ -150,7 +150,7 @@ describe('Dynamic Instrumentation', function () {
       })
 
       it('should respect maxLength', function (done) {
-        t.agent.on('debugger-input', ({ payload: { 'debugger.snapshot': { captures } } }) => {
+        t.agent.on('debugger-input', ({ payload: [{ 'debugger.snapshot': { captures } }] }) => {
           const { locals } = captures.lines[t.breakpoint.line]
 
           assert.deepEqual(locals.lstr, {
@@ -167,7 +167,7 @@ describe('Dynamic Instrumentation', function () {
       })
 
       it('should respect maxCollectionSize', function (done) {
-        t.agent.on('debugger-input', ({ payload: { 'debugger.snapshot': { captures } } }) => {
+        t.agent.on('debugger-input', ({ payload: [{ 'debugger.snapshot': { captures } }] }) => {
           const { locals } = captures.lines[t.breakpoint.line]
 
           assert.deepEqual(locals.arr, {
@@ -205,7 +205,7 @@ describe('Dynamic Instrumentation', function () {
           }
         }
 
-        t.agent.on('debugger-input', ({ payload: { 'debugger.snapshot': { captures } } }) => {
+        t.agent.on('debugger-input', ({ payload: [{ 'debugger.snapshot': { captures } }] }) => {
           const { locals } = captures.lines[t.breakpoint.line]
 
           assert.deepEqual(Object.keys(locals), [

integration-tests/debugger/utils.js

@@ -50,9 +50,11 @@ function setup ({ env, testApp } = {}) {
   function triggerBreakpoint (url) {
     // Trigger the breakpoint once probe is successfully installed
     t.agent.on('debugger-diagnostics', ({ payload }) => {
-      if (payload.debugger.diagnostics.status === 'INSTALLED') {
-        t.axios.get(url)
-      }
+      payload.forEach((event) => {
+        if (event.debugger.diagnostics.status === 'INSTALLED') {
+          t.axios.get(url)
+        }
+      })
     })
   }
 

packages/dd-trace/src/debugger/devtools_client/config.js

@@ -9,7 +9,8 @@ const config = module.exports = {
   service: parentConfig.service,
   commitSHA: parentConfig.commitSHA,
   repositoryUrl: parentConfig.repositoryUrl,
-  parentThreadId
+  parentThreadId,
+  maxTotalPayloadSize: 5 * 1024 * 1024 // 5MB
 }
 
 updateUrl(parentConfig)

packages/dd-trace/src/debugger/devtools_client/index.js

@@ -129,9 +129,8 @@ session.on('Debugger.paused', async ({ params }) => {
     }
 
     // TODO: Process template (DEBUG-2628)
-    send(probe.template, logger, dd, snapshot, (err) => {
-      if (err) log.error('Debugger error', err)
-      else ackEmitting(probe)
+    send(probe.template, logger, dd, snapshot, () => {
+      ackEmitting(probe)
     })
   }
 })

packages/dd-trace/src/debugger/devtools_client/json-buffer.js

@@ -0,0 +1,36 @@
+'use strict'
+
+class JSONBuffer {
+  constructor ({ size, timeout, onFlush }) {
+    this._maxSize = size
+    this._timeout = timeout
+    this._onFlush = onFlush
+    this._reset()
+  }
+
+  _reset () {
+    clearTimeout(this._timer)
+    this._timer = null
+    this._partialJson = null
+  }
+
+  _flush () {
+    const json = `${this._partialJson}]`
+    this._reset()
+    this._onFlush(json)
+  }
+
+  write (str, size = Buffer.byteLength(str)) {
+    if (this._timer === null) {
+      this._partialJson = `[${str}`
+      this._timer = setTimeout(() => this._flush(), this._timeout)
+    } else if (Buffer.byteLength(this._partialJson) + size + 2 > this._maxSize) {
+      this._flush()
+      this.write(str, size)
+    } else {
+      this._partialJson += `,${str}`
+    }
+  }
+}
+
+module.exports = JSONBuffer

packages/dd-trace/src/debugger/devtools_client/send.js

@@ -4,13 +4,15 @@ const { hostname: getHostname } = require('os')
 const { stringify } = require('querystring')
 
 const config = require('./config')
+const JSONBuffer = require('./json-buffer')
 const request = require('../../exporters/common/request')
 const { GIT_COMMIT_SHA, GIT_REPOSITORY_URL } = require('../../plugins/util/tags')
+const log = require('../../log')
 const { version } = require('../../../../../package.json')
 
 module.exports = send
 
-const MAX_PAYLOAD_SIZE = 1024 * 1024 // 1MB
+const MAX_LOG_PAYLOAD_SIZE = 1024 * 1024 // 1MB
 
 const ddsource = 'dd_debugger'
 const hostname = getHostname()
@@ -27,14 +29,10 @@ const ddtags = [
 
 const path = `/debugger/v1/input?${stringify({ ddtags })}`
 
-function send (message, logger, dd, snapshot, cb) {
-  const opts = {
-    method: 'POST',
-    url: config.url,
-    path,
-    headers: { 'Content-Type': 'application/json; charset=utf-8' }
-  }
+let callbacks = []
+const jsonBuffer = new JSONBuffer({ size: config.maxTotalPayloadSize, timeout: 1000, onFlush })
 
+function send (message, logger, dd, snapshot, cb) {
   const payload = {
     ddsource,
     hostname,
@@ -46,16 +44,36 @@ function send (message, logger, dd, snapshot, cb) {
   }
 
   let json = JSON.stringify(payload)
+  let size = Buffer.byteLength(json)
 
-  if (Buffer.byteLength(json) > MAX_PAYLOAD_SIZE) {
+  if (size > MAX_LOG_PAYLOAD_SIZE) {
     // TODO: This is a very crude way to handle large payloads. Proper pruning will be implemented later (DEBUG-2624)
     const line = Object.values(payload['debugger.snapshot'].captures.lines)[0]
     line.locals = {
       notCapturedReason: 'Snapshot was too large',
       size: Object.keys(line.locals).length
     }
     json = JSON.stringify(payload)
+    size = Buffer.byteLength(json)
+  }
+
+  jsonBuffer.write(json, size)
+  callbacks.push(cb)
+}
+
+function onFlush (payload) {
+  const opts = {
+    method: 'POST',
+    url: config.url,
+    path,
+    headers: { 'Content-Type': 'application/json; charset=utf-8' }
   }
 
-  request(json, opts, cb)
+  const _callbacks = callbacks
+  callbacks = []
+
+  request(payload, opts, (err) => {
+    if (err) log.error('Could not send debugger payload', err)
+    else _callbacks.forEach(cb => cb())
+  })
 }

packages/dd-trace/src/debugger/devtools_client/status.js

@@ -2,6 +2,7 @@
 
 const LRUCache = require('lru-cache')
 const config = require('./config')
+const JSONBuffer = require('./json-buffer')
 const request = require('../../exporters/common/request')
 const FormData = require('../../exporters/common/form-data')
 const log = require('../../log')
@@ -25,6 +26,8 @@ const cache = new LRUCache({
   ttlAutopurge: true
 })
 
+const jsonBuffer = new JSONBuffer({ size: config.maxTotalPayloadSize, timeout: 1000, onFlush })
+
 const STATUSES = {
   RECEIVED: 'RECEIVED',
   INSTALLED: 'INSTALLED',
@@ -71,11 +74,15 @@ function ackError (err, { id: probeId, version }) {
 }
 
 function send (payload) {
+  jsonBuffer.write(JSON.stringify(payload))
+}
+
+function onFlush (payload) {
   const form = new FormData()
 
   form.append(
     'event',
-    JSON.stringify(payload),
+    payload,
     { filename: 'event.json', contentType: 'application/json; charset=utf-8' }
   )
 
@@ -87,7 +94,7 @@ function send (payload) {
   }
 
   request(form, options, (err) => {
-    if (err) log.error('[debugger:devtools_client] Error sending debugger payload', err)
+    if (err) log.error('[debugger:devtools_client] Error sending probe payload', err)
   })
 }
 

packages/dd-trace/test/debugger/devtools_client/json-buffer.spec.js

@@ -0,0 +1,45 @@
+'use strict'
+
+require('../../setup/mocha')
+
+const JSONBuffer = require('../../../src/debugger/devtools_client/json-buffer')
+
+const MAX_SAFE_SIGNED_INTEGER = 2 ** 31 - 1
+
+describe('JSONBuffer', () => {
+  it('should call onFlush with the expected payload when the timeout is reached', function (done) {
+    const onFlush = (json) => {
+      const diff = Date.now() - start
+      expect(json).to.equal('[{"message":1},{"message":2},{"message":3}]')
+      expect(diff).to.be.within(95, 110)
+      done()
+    }
+
+    const jsonBuffer = new JSONBuffer({ size: Infinity, timeout: 100, onFlush })
+
+    const start = Date.now()
+    jsonBuffer.write(JSON.stringify({ message: 1 }))
+    jsonBuffer.write(JSON.stringify({ message: 2 }))
+    jsonBuffer.write(JSON.stringify({ message: 3 }))
+  })
+
+  it('should call onFlush with the expected payload when the size is reached', function (done) {
+    const expectedPayloads = [
+      '[{"message":1},{"message":2}]',
+      '[{"message":3},{"message":4}]'
+    ]
+
+    const onFlush = (json) => {
+      expect(json).to.equal(expectedPayloads.shift())
+      if (expectedPayloads.length === 0) done()
+    }
+
+    const jsonBuffer = new JSONBuffer({ size: 30, timeout: MAX_SAFE_SIGNED_INTEGER, onFlush })
+
+    jsonBuffer.write(JSON.stringify({ message: 1 })) // size: 15
+    jsonBuffer.write(JSON.stringify({ message: 2 })) // size: 29
+    jsonBuffer.write(JSON.stringify({ message: 3 })) // size: 15 (flushed, and re-added)
+    jsonBuffer.write(JSON.stringify({ message: 4 })) // size: 29
+    jsonBuffer.write(JSON.stringify({ message: 5 })) // size: 15 (flushed, and re-added)
+  })
+})