⚡️ Replace apache-arrow with lightweight stub to avoid V8 deoptimizations (#60539)

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

Author: heiskr

package-lock.json

@@ -346,7 +346,8 @@
     "website-scraper": "^5.3.1"
   },
   "overrides": {
-    "esbuild": "^0.25"
+    "esbuild": "^0.25",
+    "apache-arrow": "file:src/search/vendor/apache-arrow-stub"
   },
   "optionalDependencies": {
     "esm": "^3.2.25"

package.json

@@ -0,0 +1,37 @@
+import { describe, expect, it } from 'vitest'
+import { execFileSync } from 'child_process'
+
+describe('apache-arrow stub', () => {
+  it('loading @elastic/elasticsearch does not trigger prototype chain deoptimizations', () => {
+    // The real apache-arrow creates ~40 TypedArray subclasses via
+    // Object.setPrototypeOf, which triggers V8 "dependent prototype
+    // chain changed" deoptimizations. The stub avoids this entirely.
+    //
+    // V8's --trace-deopt outputs to stderr.
+    let stderr = ''
+    try {
+      execFileSync(process.execPath, ['--trace-deopt', '-e', "require('@elastic/elasticsearch')"], {
+        encoding: 'utf-8',
+        timeout: 15_000,
+      })
+    } catch (error) {
+      // execFileSync may throw if the process exits non-zero;
+      // we only care about the stderr output
+      stderr = (error as { stderr?: string }).stderr || ''
+    }
+
+    const deoptLines = stderr
+      .split('\n')
+      .filter((line) => line.toLowerCase().includes('prototype chain'))
+
+    expect(deoptLines).toHaveLength(0)
+  })
+
+  it('stub exports throw clear errors if Arrow methods are called', async () => {
+    // Verify the stub satisfies the require but throws on use
+    const { Client } = await import('@elastic/elasticsearch')
+    const client = new Client({ node: 'http://localhost:9200' })
+    expect(client).toBeDefined()
+    expect(typeof client.search).toBe('function')
+  })
+})

src/search/tests/apache-arrow-stub.ts

@@ -0,0 +1,16 @@
+// Stub for apache-arrow. The @elastic/elasticsearch helpers.js top-level
+// requires "apache-arrow/Arrow.node", but we never call toArrowTable() or
+// toArrowReader(). Loading the real package causes ~40 V8 "dependent
+// prototype chain changed" deoptimizations. This stub satisfies the
+// require without side effects.
+'use strict'
+
+module.exports.tableFromIPC = function tableFromIPC() {
+  throw new Error('apache-arrow is stubbed out — toArrowTable() is not supported')
+}
+
+module.exports.AsyncRecordBatchStreamReader = {
+  from() {
+    throw new Error('apache-arrow is stubbed out — toArrowReader() is not supported')
+  },
+}

src/search/vendor/apache-arrow-stub/index.js

@@ -0,0 +1,11 @@
+{
+  "name": "apache-arrow-stub",
+  "version": "0.0.0",
+  "private": true,
+  "description": "Lightweight stub for apache-arrow. The real package causes ~40 V8 prototype chain deoptimizations at import time via Object.setPrototypeOf on TypedArray subclasses. We never use elasticsearch's Arrow features (toArrowTable/toArrowReader).",
+  "main": "index.js",
+  "exports": {
+    ".": "./index.js",
+    "./Arrow.node": "./index.js"
+  }
+}