Remove clustering, remove WEB_CONCURRENCY setting (github#24914)

* Remove WEB_CONCURRENCY setting

Dockerfile

@@ -76,9 +76,6 @@ ENV NODE_ENV production
 # Whether to hide iframes, add warnings to external links
 ENV AIRGAP false
 
-# By default we typically don't want to run in clustered mode
-ENV WEB_CONCURRENCY 1
-
 # Preferred port for server.mjs
 ENV PORT 4000
 

azure-preview-env-template.json

@@ -83,10 +83,6 @@
                           "name": "DEPLOYMENT_ENV",
                           "value": "azure"
                       },
-                      {
-                          "name": "WEB_CONCURRENCY",
-                          "value": "1"
-                      },
                       {
                           "name": "ENABLED_LANGUAGES",
                           "value": "en"

docker-compose.prod.tmpl.yaml

@@ -12,7 +12,6 @@ services:
       HYDRO_ENDPOINT: ${HYDRO_ENDPOINT}
       HYDRO_SECRET: ${HYDRO_SECRET}
       HAYSTACK_URL: ${HAYSTACK_URL}
-      WEB_CONCURRENCY: ${WEB_CONCURRENCY}
       HEROKU_APP_NAME: ${HEROKU_APP_NAME}
       ENABLED_LANGUAGES: ${ENABLED_LANGUAGES}
       DEPLOYMENT_ENV: ${DEPLOYMENT_ENV}

package.json

@@ -87,7 +87,6 @@
     "strip-html-comments": "^1.0.0",
     "styled-components": "^5.3.3",
     "swr": "1.1.2",
-    "throng": "^5.0.0",
     "ts-dedent": "^2.2.0",
     "unified": "^10.1.0",
     "unist-util-visit": "^4.1.0",
@@ -193,7 +192,7 @@
   "repository": "https://github.com/github/docs",
   "scripts": {
     "browser-test": "start-server-and-test browser-test-server 4001 browser-test-tests",
-    "browser-test-server": "cross-env NODE_ENV=production WEB_CONCURRENCY=1 PORT=4001 ENABLED_LANGUAGES=en,ja node server.mjs",
+    "browser-test-server": "cross-env NODE_ENV=production PORT=4001 ENABLED_LANGUAGES=en,ja node server.mjs",
     "browser-test-tests": "cross-env BROWSER=1 NODE_OPTIONS=--experimental-vm-modules jest tests/browser/browser.js",
     "build": "next build",
     "debug": "cross-env NODE_ENV=development ENABLED_LANGUAGES='en,ja' nodemon --inspect server.mjs",
@@ -214,7 +213,7 @@
     "sync-search": "cross-env NODE_OPTIONS='--max_old_space_size=8192' start-server-and-test sync-search-server 4002 sync-search-indices",
     "sync-search-ghes-release": "cross-env GHES_RELEASE=1 start-server-and-test sync-search-server 4002 sync-search-indices",
     "sync-search-indices": "script/sync-search-indices.js",
-    "sync-search-server": "cross-env NODE_ENV=production WEB_CONCURRENCY=1 PORT=4002 node server.mjs",
+    "sync-search-server": "cross-env NODE_ENV=production PORT=4002 node server.mjs",
     "translation-check": "start-server-and-test translation-check-server 4002 translation-check-test",
     "translation-check-server": "cross-env NODE_ENV=test PORT=4002 node server.mjs",
     "translation-check-test": "script/i18n/test-html-pages.js",

server.mjs

@@ -2,37 +2,20 @@ import dotenv from 'dotenv'
 import './lib/feature-flags.js'
 import './lib/check-node-version.js'
 import './lib/handle-exceptions.js'
-import throng from 'throng'
-import os from 'os'
 import portUsed from 'port-used'
-import prefixStreamWrite from './lib/prefix-stream-write.js'
 import createApp from './lib/app.js'
 import warmServer from './lib/warm-server.js'
 import http from 'http'
 dotenv.config()
-// Intentionally require these for both cluster primary and workers
 
 const { PORT, NODE_ENV } = process.env
 const port = Number(PORT) || 4000
 
-// Start the server!
-if (NODE_ENV === 'production') {
-  clusteredMain()
-} else {
-  nonClusteredMain()
-}
-
-function clusteredMain() {
-  // Spin up a cluster!
-  throng({
-    master: setupPrimary,
-    worker: setupWorker,
-    count: calculateWorkerCount(),
-  })
-}
+async function main() {
+  if (NODE_ENV !== 'production') {
+    await checkPortAvailability()
+  }
 
-async function nonClusteredMain() {
-  await checkPortAvailability()
   await startServer()
 }
 
@@ -69,68 +52,4 @@ async function startServer() {
     .on('error', () => server.close())
 }
 
-// This function will only be run in the primary process
-async function setupPrimary() {
-  process.on('beforeExit', () => {
-    console.log('Shutting down primary...')
-    console.log('Exiting!')
-  })
-
-  console.log('Starting up primary...')
-
-  await checkPortAvailability()
-}
-
-// IMPORTANT: This function will be run in a separate worker process!
-async function setupWorker(id, disconnect) {
-  let exited = false
-
-  // Wrap stdout and stderr to include the worker ID as a static prefix
-  // console.log('hi') => '[worker.1]: hi'
-  const prefix = `[worker.${id}]: `
-  prefixStreamWrite(process.stdout, prefix)
-  prefixStreamWrite(process.stderr, prefix)
-
-  process.on('beforeExit', () => {
-    console.log('Exiting!')
-  })
-
-  process.on('SIGTERM', shutdown)
-  process.on('SIGINT', shutdown)
-
-  console.log('Starting up worker...')
-
-  // Load the server in each worker process and share the port via sharding
-  await startServer()
-
-  function shutdown() {
-    if (exited) return
-    exited = true
-
-    console.log('Shutting down worker...')
-    disconnect()
-  }
-}
-
-function calculateWorkerCount() {
-  // Heroku's recommended WEB_CONCURRENCY count based on the WEB_MEMORY config,
-  // or explicitly configured by us
-  const { WEB_CONCURRENCY } = process.env
-
-  const recommendedCount = parseInt(WEB_CONCURRENCY, 10)
-  const cpuCount = os.cpus().length
-
-  // Ensure the recommended count is AT LEAST 1 for safety
-  let workerCount = Math.max(recommendedCount || 1, 1)
-
-  // If WEB_CONCURRENCY value was configured to a valid number...
-  if (recommendedCount > 0) {
-    // Use the smaller value between the recommendation vs. the CPU count
-    workerCount = Math.min(workerCount, cpuCount)
-  } else if (NODE_ENV === 'production') {
-    // Else if in a deployed environment, default to the CPU count
-    workerCount = cpuCount
-  }
-
-  return workerCount
-}
+main()