From a98ad7a55e4f73922a18320c8c3f9e831cd79d1e Mon Sep 17 00:00:00 2001
From: Tiago Costa <tiagoffcc@hotmail.com>
Date: Fri, 7 Feb 2020 19:22:36 +0000
Subject: [PATCH] chore(NA): removes use of parallel option in the terser
 minimizer (#57077)

* chore(NA): removes use of parallel option in the terser minimizer

* docs(NA): update note
---
 src/optimize/base_optimizer.js                   |  2 +-
 .../dynamic_dll_plugin/dll_config_model.js       | 16 ++++++++++------
 2 files changed, 11 insertions(+), 7 deletions(-)

diff --git a/src/optimize/base_optimizer.js b/src/optimize/base_optimizer.js
index d9df2a1955df3..539c55c969653 100644
--- a/src/optimize/base_optimizer.js
+++ b/src/optimize/base_optimizer.js
@@ -459,7 +459,7 @@ export default class BaseOptimizer {
       optimization: {
         minimizer: [
           new TerserPlugin({
-            parallel: this.getThreadLoaderPoolConfig().workers,
+            parallel: false,
             sourceMap: false,
             cache: false,
             extractComments: false,
diff --git a/src/optimize/dynamic_dll_plugin/dll_config_model.js b/src/optimize/dynamic_dll_plugin/dll_config_model.js
index 2e74cb6af86d4..9ca6071b8f515 100644
--- a/src/optimize/dynamic_dll_plugin/dll_config_model.js
+++ b/src/optimize/dynamic_dll_plugin/dll_config_model.js
@@ -214,16 +214,20 @@ function common(config) {
   return webpackMerge(generateDLL(config));
 }
 
-function optimized(config) {
+function optimized() {
   return webpackMerge({
     mode: 'production',
     optimization: {
       minimizer: [
         new TerserPlugin({
-          // Apply the same logic used to calculate the
-          // threadLoaderPool workers number to spawn
-          // the parallel processes on terser
-          parallel: config.threadLoaderPoolConfig.workers,
+          // NOTE: we should not enable that option for now
+          // Since 2.0.0 terser-webpack-plugin is using jest-worker
+          // to run tasks in a pool of workers. Currently it looks like
+          // is requiring too much memory and break on large entry points
+          // compilations (like this) one. Also the gain we have enabling
+          // that option was barely noticed.
+          // https://github.com/webpack-contrib/terser-webpack-plugin/issues/143
+          parallel: false,
           sourceMap: false,
           cache: false,
           extractComments: false,
@@ -250,5 +254,5 @@ export function configModel(rawConfig = {}) {
     return webpackMerge(common(config), unoptimized());
   }
 
-  return webpackMerge(common(config), optimized(config));
+  return webpackMerge(common(config), optimized());
 }