From 749dbdf5812c90342991e9f38008c99511432b22 Mon Sep 17 00:00:00 2001
From: Copilot <198982749+Copilot@users.noreply.github.com>
Date: Tue, 10 Feb 2026 15:19:22 +0000
Subject: [PATCH] [Fleet] Make save_knowledge_base async in streaming state
 machine (#252328)

(cherry picked from commit 34ea9669a58ae968c3d0ce3f5e5c2bb546de15ba)
---
 .../_state_machine_package_install.test.ts    | 27 ++++++++++++++++++-
 .../_state_machine_package_install.ts         |  5 ++--
 2 files changed, 29 insertions(+), 3 deletions(-)

diff --git a/x-pack/platform/plugins/shared/fleet/server/services/epm/packages/install_state_machine/_state_machine_package_install.test.ts b/x-pack/platform/plugins/shared/fleet/server/services/epm/packages/install_state_machine/_state_machine_package_install.test.ts
index dfd6cce6b91bc..61ba44d078dd8 100644
--- a/x-pack/platform/plugins/shared/fleet/server/services/epm/packages/install_state_machine/_state_machine_package_install.test.ts
+++ b/x-pack/platform/plugins/shared/fleet/server/services/epm/packages/install_state_machine/_state_machine_package_install.test.ts
@@ -41,7 +41,11 @@ import { installIndexTemplatesAndPipelines } from '../install_index_template_pip
 import { createArchiveIteratorFromMap } from '../../archive/archive_iterator';
 
 import { handleState } from './state_machine';
-import { _stateMachineInstallPackage } from './_state_machine_package_install';
+import {
+  _stateMachineInstallPackage,
+  regularStatesDefinition,
+  streamingStatesDefinition,
+} from './_state_machine_package_install';
 import { cleanupLatestExecutedState } from './steps';
 
 jest.mock('./state_machine');
@@ -347,3 +351,24 @@ describe('_stateMachineInstallPackage', () => {
     await expect(installPromise).rejects.toThrowError(PackageSavedObjectConflictError);
   });
 });
+
+describe('State machine parity', () => {
+  it('should have matching isAsync flags for common states in both regularStatesDefinition and streamingStatesDefinition', () => {
+    const commonStates = [
+      'create_restart_installation',
+      'install_kibana_assets',
+      'save_archive_entries_from_assets_map',
+      'save_knowledge_base',
+      'update_so',
+    ] as const;
+
+    commonStates.forEach((stateName) => {
+      const regularState = regularStatesDefinition[stateName];
+      const streamingState = streamingStatesDefinition[stateName];
+
+      if (regularState && streamingState) {
+        expect(regularState.isAsync).toEqual(streamingState.isAsync);
+      }
+    });
+  });
+});
diff --git a/x-pack/platform/plugins/shared/fleet/server/services/epm/packages/install_state_machine/_state_machine_package_install.ts b/x-pack/platform/plugins/shared/fleet/server/services/epm/packages/install_state_machine/_state_machine_package_install.ts
index bae775c66f6e8..615817fa629e9 100644
--- a/x-pack/platform/plugins/shared/fleet/server/services/epm/packages/install_state_machine/_state_machine_package_install.ts
+++ b/x-pack/platform/plugins/shared/fleet/server/services/epm/packages/install_state_machine/_state_machine_package_install.ts
@@ -91,7 +91,7 @@ export interface InstallContext extends StateContext<StateNames> {
 /**
  * This data structure defines the sequence of the states and the transitions
  */
-const regularStatesDefinition: StateMachineStates<StateNames> = {
+export const regularStatesDefinition: StateMachineStates<StateNames> = {
   create_restart_installation: {
     nextState: INSTALL_STATES.INSTALL_PRECHECK,
     onTransition: stepCreateRestartInstallation,
@@ -183,7 +183,7 @@ const regularStatesDefinition: StateMachineStates<StateNames> = {
   },
 };
 
-const streamingStatesDefinition: StateMachineStates<string> = {
+export const streamingStatesDefinition: StateMachineStates<string> = {
   create_restart_installation: {
     nextState: INSTALL_STATES.INSTALL_KIBANA_ASSETS,
     onTransition: stepCreateRestartInstallation,
@@ -205,6 +205,7 @@ const streamingStatesDefinition: StateMachineStates<string> = {
     onTransition: stepSaveKnowledgeBase,
     nextState: INSTALL_STATES.UPDATE_SO,
     onPostTransition: updateLatestExecutedState,
+    isAsync: true, // Knowledge base indexing runs in background
   },
   update_so: {
     onPreTransition: cleanUpUnusedKibanaAssetsStep,