From 054913c87cbf93fd0de06077ae35339e38912678 Mon Sep 17 00:00:00 2001
From: spalger <spalger@users.noreply.github.com>
Date: Tue, 11 Aug 2020 15:39:51 -0700
Subject: [PATCH] revert change to max worker count

---
 .../src/optimizer/optimizer_config.test.ts       | 16 ++++++++--------
 .../src/optimizer/optimizer_config.ts            | 14 +++++++++-----
 2 files changed, 17 insertions(+), 13 deletions(-)

diff --git a/packages/kbn-optimizer/src/optimizer/optimizer_config.test.ts b/packages/kbn-optimizer/src/optimizer/optimizer_config.test.ts
index 2eb04706fae69d..afc2dc8952c87a 100644
--- a/packages/kbn-optimizer/src/optimizer/optimizer_config.test.ts
+++ b/packages/kbn-optimizer/src/optimizer/optimizer_config.test.ts
@@ -121,7 +121,7 @@ describe('OptimizerConfig::parseOptions()', () => {
         "filters": Array [],
         "includeCoreBundle": false,
         "inspectWorkers": false,
-        "maxWorkerCount": 3,
+        "maxWorkerCount": 2,
         "outputRoot": <absolute path>,
         "pluginPaths": Array [],
         "pluginScanDirs": Array [
@@ -149,7 +149,7 @@ describe('OptimizerConfig::parseOptions()', () => {
         "filters": Array [],
         "includeCoreBundle": false,
         "inspectWorkers": false,
-        "maxWorkerCount": 3,
+        "maxWorkerCount": 2,
         "outputRoot": <absolute path>,
         "pluginPaths": Array [],
         "pluginScanDirs": Array [
@@ -177,7 +177,7 @@ describe('OptimizerConfig::parseOptions()', () => {
         "filters": Array [],
         "includeCoreBundle": false,
         "inspectWorkers": false,
-        "maxWorkerCount": 3,
+        "maxWorkerCount": 2,
         "outputRoot": <absolute path>,
         "pluginPaths": Array [],
         "pluginScanDirs": Array [
@@ -207,7 +207,7 @@ describe('OptimizerConfig::parseOptions()', () => {
         "filters": Array [],
         "includeCoreBundle": false,
         "inspectWorkers": false,
-        "maxWorkerCount": 3,
+        "maxWorkerCount": 2,
         "outputRoot": <absolute path>,
         "pluginPaths": Array [],
         "pluginScanDirs": Array [
@@ -234,7 +234,7 @@ describe('OptimizerConfig::parseOptions()', () => {
         "filters": Array [],
         "includeCoreBundle": false,
         "inspectWorkers": false,
-        "maxWorkerCount": 3,
+        "maxWorkerCount": 2,
         "outputRoot": <absolute path>,
         "pluginPaths": Array [],
         "pluginScanDirs": Array [
@@ -449,7 +449,7 @@ describe('OptimizerConfig::create()', () => {
           [Window],
         ],
         "invocationCallOrder": Array [
-          15,
+          21,
         ],
         "results": Array [
           Object {
@@ -475,7 +475,7 @@ describe('OptimizerConfig::create()', () => {
           [Window],
         ],
         "invocationCallOrder": Array [
-          17,
+          23,
         ],
         "results": Array [
           Object {
@@ -499,7 +499,7 @@ describe('OptimizerConfig::create()', () => {
           [Window],
         ],
         "invocationCallOrder": Array [
-          16,
+          22,
         ],
         "results": Array [
           Object {
diff --git a/packages/kbn-optimizer/src/optimizer/optimizer_config.ts b/packages/kbn-optimizer/src/optimizer/optimizer_config.ts
index bfbfbd24b41bf3..45598ff8831b0b 100644
--- a/packages/kbn-optimizer/src/optimizer/optimizer_config.ts
+++ b/packages/kbn-optimizer/src/optimizer/optimizer_config.ts
@@ -33,10 +33,14 @@ import { findKibanaPlatformPlugins, KibanaPlatformPlugin } from './kibana_platfo
 import { getPluginBundles } from './get_plugin_bundles';
 import { filterById } from './filter_by_id';
 
-// don't break if cpus() returns nothing, or an empty array
-const CPU_COUNT = Math.max(Os.cpus()?.length, 1);
-// ensure we have at least three workers
-const MAX_WORKER_COUNT = Math.max(CPU_COUNT - 1, 3);
+function pickMaxWorkerCount(dist: boolean) {
+  // don't break if cpus() returns nothing, or an empty array
+  const cpuCount = Math.max(Os.cpus()?.length, 1);
+  // if we're buiding the dist then we can use more of the system's resources to get things done a little quicker
+  const maxWorkers = dist ? cpuCount - 1 : Math.ceil(cpuCount / 3);
+  // ensure we always have at least two workers
+  return Math.max(maxWorkers, 2);
+}
 
 function omit<T, K extends keyof T>(obj: T, keys: K[]): Omit<T, K> {
   const result: any = {};
@@ -178,7 +182,7 @@ export class OptimizerConfig {
 
     const maxWorkerCount = process.env.KBN_OPTIMIZER_MAX_WORKERS
       ? parseInt(process.env.KBN_OPTIMIZER_MAX_WORKERS, 10)
-      : options.maxWorkerCount ?? MAX_WORKER_COUNT;
+      : options.maxWorkerCount ?? pickMaxWorkerCount(dist);
     if (typeof maxWorkerCount !== 'number' || !Number.isFinite(maxWorkerCount)) {
       throw new TypeError('worker count must be a number');
     }