From 492a97e288527d57a02ccaa6ec9106c9bcb3b4de Mon Sep 17 00:00:00 2001
From: Jean-Louis Leysens <jloleysens@gmail.com>
Date: Mon, 9 Mar 2020 14:11:31 +0100
Subject: [PATCH] [Upgrade Assistant] Better handling of closed indices
 (#58890)

* Exclude disallowed, private setting at index creation

* Remove intl from tabs component

* Added logic for checking the current index status

* Added ES contract integration test

Using _cluster/state is considered internal. This adds an integration
test for checking the contract in CI.

* Add the client side notification for closed indices

* First version of end-to-end functionality working

* Clean up unused, incorrect type information

* Fix type issues and added a comment about the new reindex options

* Fixed server side tests, added comments and logic updates

Updated the handling of reindexOptions to make it more
backwards compatible (treat it as if it could be undefined).

Also update the logic for checking for open or closed indices.
No optional chaining! It should break if the response does not
exactly match.

* Clean up unused code

* Improved idempotency of test and check explicitly for "close".

Rather check for the specific value we want, as this is what is
also gauranteed by the tests. In this way, the information we
send back to the client is also more accurate regarding the index
status. If, in future, more index states are introduced this will
need to be revisited if it affects the ability for an index to be
re-indexed.

* Update client-side tests

* Fix types

* Handle a case where the index name provided may be an alias

* Fix types

* merge-conflict: finish merge conflict resolution

* Update x-pack/plugins/upgrade_assistant/public/application/components/tabs/checkup/deprecations/reindex/closed_warning_icon.tsx

Co-Authored-By: Alison Goryachev <alisonmllr20@gmail.com>

* merge-conflict: Remove duplicate import

VSCode does not auto-save as expected :sigh:

* ui: Revisit the UI

Moved the warning icon to inside of the button and tooltip to
on the button.

Added a callout to the reindex flyout for when an index is closed.

* logic: slight update to when the index closed callout is shown

We only show the index closed callout in the flyout when the
reindex operation is not considered "completed"

* tests: fix jest tests

* refactor: remove "openAndClose" from reindex endpoints

"openAndClose" should just happen automatically. The user should
not have to pass the flag in, that would be a weird API. We just
need to warn the user about that reindexing a closed index will
take more resources

* test: update upgrade assistant integration test

* fix: types

* copy: use sentence case

* refactor: use the in scope declaration of reindex op

* test: Clean up tests

Reindexing test was generating index name, could just get it from
server response. Also removed openAndClose from all integration
tests

Co-authored-by: Elastic Machine <elasticmachine@users.noreply.github.com>
Co-authored-by: Alison Goryachev <alisonmllr20@gmail.com>
---
 ...get_index_state_from_cluster_state.test.ts |  53 +++++++
 .../get_index_state_from_cluster_state.ts     |  28 ++++
 .../plugins/upgrade_assistant/common/types.ts |  55 ++++++-
 .../public/application/app_context.tsx        |   3 +-
 .../public/application/components/tabs.tsx    |  27 ++--
 .../tabs/checkup/deprecations/cell.tsx        |  12 +-
 .../tabs/checkup/deprecations/index_table.tsx |  22 ++-
 .../tabs/checkup/deprecations/list.test.tsx   | 148 +++++++++---------
 .../tabs/checkup/deprecations/list.tsx        |  10 +-
 .../checkup/deprecations/reindex/button.tsx   |  49 +++++-
 .../reindex/flyout/checklist_step.test.tsx    |   1 +
 .../reindex/flyout/checklist_step.tsx         |   4 +-
 .../deprecations/reindex/flyout/container.tsx |  78 ++++++++-
 .../reindex/flyout/warning_step.test.tsx      |   1 +
 .../reindex/flyout/warnings_step.tsx          |   4 +-
 .../deprecations/reindex/polling_service.ts   |   1 +
 .../upgrade_assistant/public/plugin.ts        |   4 +-
 .../es_migration_apis.test.ts.snap            |   6 +
 .../server/lib/es_indices_state_check.ts      |  36 +++++
 .../server/lib/es_migration_apis.test.ts      |  17 +-
 .../server/lib/es_migration_apis.ts           |  15 ++
 .../server/lib/reindexing/index_settings.ts   |   1 +
 .../lib/reindexing/reindex_actions.test.ts    |   4 +
 .../server/lib/reindexing/reindex_actions.ts  |   2 +-
 .../lib/reindexing/reindex_service.test.ts    |  12 +-
 .../server/lib/reindexing/reindex_service.ts  |  17 +-
 .../routes/reindex_indices/reindex_handler.ts |  14 +-
 .../reindex_indices/reindex_indices.test.ts   |  14 +-
 .../routes/reindex_indices/reindex_indices.ts |   9 +-
 .../upgrade_assistant/index.js                |   1 +
 .../upgrade_assistant/reindexing.js           |  17 ++
 .../upgrade_assistant/status.ts               |  57 +++++++
 32 files changed, 596 insertions(+), 126 deletions(-)
 create mode 100644 x-pack/plugins/upgrade_assistant/common/get_index_state_from_cluster_state.test.ts
 create mode 100644 x-pack/plugins/upgrade_assistant/common/get_index_state_from_cluster_state.ts
 create mode 100644 x-pack/plugins/upgrade_assistant/server/lib/es_indices_state_check.ts
 create mode 100644 x-pack/test/upgrade_assistant_integration/upgrade_assistant/status.ts

diff --git a/x-pack/plugins/upgrade_assistant/common/get_index_state_from_cluster_state.test.ts b/x-pack/plugins/upgrade_assistant/common/get_index_state_from_cluster_state.test.ts
new file mode 100644
index 00000000000000..1098594a68f8a2
--- /dev/null
+++ b/x-pack/plugins/upgrade_assistant/common/get_index_state_from_cluster_state.test.ts
@@ -0,0 +1,53 @@
+/*
+ * Copyright Elasticsearch B.V. and/or licensed to Elasticsearch B.V. under one
+ * or more contributor license agreements. Licensed under the Elastic License;
+ * you may not use this file except in compliance with the Elastic License.
+ */
+import { getIndexStateFromClusterState } from './get_index_state_from_cluster_state';
+import { ClusterStateAPIResponse } from './types';
+
+describe('getIndexStateFromClusterState', () => {
+  const indexName = 'indexName';
+  const clusterState: ClusterStateAPIResponse = {
+    metadata: {
+      indices: {},
+      cluster_coordination: {} as any,
+      cluster_uuid: 'test',
+      templates: {} as any,
+    },
+    cluster_name: 'test',
+    cluster_uuid: 'test',
+  };
+
+  afterEach(() => {
+    clusterState.metadata.indices = {};
+  });
+
+  it('correctly extracts state from cluster state', () => {
+    clusterState.metadata.indices[indexName] = { state: 'open' } as any;
+    clusterState.metadata.indices.aTotallyDifferentIndex = { state: 'close' } as any;
+    expect(getIndexStateFromClusterState(indexName, clusterState)).toBe('open');
+  });
+
+  it('correctly extracts state from aliased index in cluster state', () => {
+    clusterState.metadata.indices.aTotallyDifferentName = {
+      state: 'close',
+      aliases: [indexName, 'test'],
+    } as any;
+    clusterState.metadata.indices.aTotallyDifferentName1 = {
+      state: 'open',
+      aliases: ['another', 'test'],
+    } as any;
+
+    expect(getIndexStateFromClusterState(indexName, clusterState)).toBe('close');
+  });
+
+  it('throws if the index name cannot be found in the cluster state', () => {
+    expect(() => getIndexStateFromClusterState(indexName, clusterState)).toThrow('not found');
+    clusterState.metadata.indices.aTotallyDifferentName1 = {
+      state: 'open',
+      aliases: ['another', 'test'],
+    } as any;
+    expect(() => getIndexStateFromClusterState(indexName, clusterState)).toThrow('not found');
+  });
+});
diff --git a/x-pack/plugins/upgrade_assistant/common/get_index_state_from_cluster_state.ts b/x-pack/plugins/upgrade_assistant/common/get_index_state_from_cluster_state.ts
new file mode 100644
index 00000000000000..75b71fee000d4a
--- /dev/null
+++ b/x-pack/plugins/upgrade_assistant/common/get_index_state_from_cluster_state.ts
@@ -0,0 +1,28 @@
+/*
+ * Copyright Elasticsearch B.V. and/or licensed to Elasticsearch B.V. under one
+ * or more contributor license agreements. Licensed under the Elastic License;
+ * you may not use this file except in compliance with the Elastic License.
+ */
+
+import { ClusterStateAPIResponse } from './types';
+
+const checkAllAliases = (
+  indexName: string,
+  clusterState: ClusterStateAPIResponse
+): 'open' | 'close' => {
+  for (const index of Object.values(clusterState.metadata.indices)) {
+    if (index.aliases?.some(alias => alias === indexName)) {
+      return index.state;
+    }
+  }
+
+  throw new Error(`${indexName} not found in cluster state!`);
+};
+
+export const getIndexStateFromClusterState = (
+  indexName: string,
+  clusterState: ClusterStateAPIResponse
+): 'open' | 'close' =>
+  clusterState.metadata.indices[indexName]
+    ? clusterState.metadata.indices[indexName].state
+    : checkAllAliases(indexName, clusterState);
diff --git a/x-pack/plugins/upgrade_assistant/common/types.ts b/x-pack/plugins/upgrade_assistant/common/types.ts
index ceb3a6dd60166f..1114e889882c26 100644
--- a/x-pack/plugins/upgrade_assistant/common/types.ts
+++ b/x-pack/plugins/upgrade_assistant/common/types.ts
@@ -34,6 +34,13 @@ export interface QueueSettings extends SavedObjectAttributes {
 }
 
 export interface ReindexOptions extends SavedObjectAttributes {
+  /**
+   * Whether to treat the index as if it were closed. This instructs the
+   * reindex strategy to first open the index, perform reindexing and
+   * then close the index again.
+   */
+  openAndClose?: boolean;
+
   /**
    * Set this key to configure a reindex operation as part of a
    * batch to be run in series.
@@ -50,7 +57,6 @@ export interface ReindexOperation extends SavedObjectAttributes {
   reindexTaskId: string | null;
   reindexTaskPercComplete: number | null;
   errorMessage: string | null;
-
   // This field is only used for the singleton IndexConsumerType documents.
   runningReindexCount: number | null;
 
@@ -142,6 +148,14 @@ export interface EnrichedDeprecationInfo extends DeprecationInfo {
   index?: string;
   node?: string;
   reindex?: boolean;
+  /**
+   * Indicate what blockers have been detected for calling reindex
+   * against this index.
+   *
+   * @remark
+   * In future this could be an array of blockers.
+   */
+  blockerForReindexing?: 'index-closed'; // 'index-closed' can be handled automatically, but requires more resources, user should be warned
 }
 
 export interface UpgradeAssistantStatus {
@@ -149,3 +163,42 @@ export interface UpgradeAssistantStatus {
   cluster: EnrichedDeprecationInfo[];
   indices: EnrichedDeprecationInfo[];
 }
+
+export interface ClusterStateIndexAPIResponse {
+  state: 'open' | 'close';
+  settings: {
+    index: {
+      verified_before_close: string;
+      search: {
+        throttled: string;
+      };
+      number_of_shards: string;
+      provided_name: string;
+      frozen: string;
+      creation_date: string;
+      number_of_replicas: string;
+      uuid: string;
+      version: {
+        created: string;
+      };
+    };
+  };
+  mappings: any;
+  aliases: string[];
+}
+
+export interface ClusterStateAPIResponse {
+  cluster_name: string;
+  cluster_uuid: string;
+  metadata: {
+    cluster_uuid: string;
+    cluster_coordination: {
+      term: number;
+      last_committed_config: string[];
+      last_accepted_config: string[];
+      voting_config_exclusions: [];
+    };
+    templates: any;
+    indices: { [indexName: string]: ClusterStateIndexAPIResponse };
+  };
+}
diff --git a/x-pack/plugins/upgrade_assistant/public/application/app_context.tsx b/x-pack/plugins/upgrade_assistant/public/application/app_context.tsx
index 1ae9dabd69481b..11c88a52ea24e0 100644
--- a/x-pack/plugins/upgrade_assistant/public/application/app_context.tsx
+++ b/x-pack/plugins/upgrade_assistant/public/application/app_context.tsx
@@ -3,12 +3,13 @@
  * or more contributor license agreements. Licensed under the Elastic License;
  * you may not use this file except in compliance with the Elastic License.
  */
-import { HttpSetup } from 'src/core/public';
+import { DocLinksStart, HttpSetup } from 'src/core/public';
 import React, { createContext, useContext } from 'react';
 
 export interface ContextValue {
   http: HttpSetup;
   isCloudEnabled: boolean;
+  docLinks: DocLinksStart;
 }
 
 export const AppContext = createContext<ContextValue>({} as any);
diff --git a/x-pack/plugins/upgrade_assistant/public/application/components/tabs.tsx b/x-pack/plugins/upgrade_assistant/public/application/components/tabs.tsx
index 43ec5554aaaeef..77ee3448cd06de 100644
--- a/x-pack/plugins/upgrade_assistant/public/application/components/tabs.tsx
+++ b/x-pack/plugins/upgrade_assistant/public/application/components/tabs.tsx
@@ -14,7 +14,8 @@ import {
   EuiTabbedContent,
   EuiTabbedContentTab,
 } from '@elastic/eui';
-import { FormattedMessage, injectI18n } from '@kbn/i18n/react';
+import { i18n } from '@kbn/i18n';
+import { FormattedMessage } from '@kbn/i18n/react';
 import { HttpSetup } from 'src/core/public';
 
 import { UpgradeAssistantStatus } from '../../../common/types';
@@ -38,9 +39,11 @@ interface TabsState {
   clusterUpgradeState: ClusterUpgradeState;
 }
 
-type Props = ReactIntl.InjectedIntlProps & { http: HttpSetup };
+interface Props {
+  http: HttpSetup;
+}
 
-export class UpgradeAssistantTabsUI extends React.Component<Props, TabsState> {
+export class UpgradeAssistantTabs extends React.Component<Props, TabsState> {
   constructor(props: Props) {
     super(props);
     this.state = {
@@ -172,7 +175,6 @@ export class UpgradeAssistantTabsUI extends React.Component<Props, TabsState> {
   };
 
   private get tabs() {
-    const { intl } = this.props;
     const { loadingError, loadingState, checkupData } = this.state;
     const commonProps: UpgradeAssistantTabProps = {
       loadingError,
@@ -186,24 +188,21 @@ export class UpgradeAssistantTabsUI extends React.Component<Props, TabsState> {
     return [
       {
         id: 'overview',
-        name: intl.formatMessage({
-          id: 'xpack.upgradeAssistant.overviewTab.overviewTabTitle',
+        name: i18n.translate('xpack.upgradeAssistant.overviewTab.overviewTabTitle', {
           defaultMessage: 'Overview',
         }),
         content: <OverviewTab checkupData={checkupData} {...commonProps} />,
       },
       {
         id: 'cluster',
-        name: intl.formatMessage({
-          id: 'xpack.upgradeAssistant.checkupTab.clusterTabLabel',
+        name: i18n.translate('xpack.upgradeAssistant.checkupTab.clusterTabLabel', {
           defaultMessage: 'Cluster',
         }),
         content: (
           <CheckupTab
             key="cluster"
             deprecations={checkupData ? checkupData.cluster : undefined}
-            checkupLabel={intl.formatMessage({
-              id: 'xpack.upgradeAssistant.tabs.checkupTab.clusterLabel',
+            checkupLabel={i18n.translate('xpack.upgradeAssistant.tabs.checkupTab.clusterLabel', {
               defaultMessage: 'cluster',
             })}
             {...commonProps}
@@ -212,16 +211,14 @@ export class UpgradeAssistantTabsUI extends React.Component<Props, TabsState> {
       },
       {
         id: 'indices',
-        name: intl.formatMessage({
-          id: 'xpack.upgradeAssistant.checkupTab.indicesTabLabel',
+        name: i18n.translate('xpack.upgradeAssistant.checkupTab.indicesTabLabel', {
           defaultMessage: 'Indices',
         }),
         content: (
           <CheckupTab
             key="indices"
             deprecations={checkupData ? checkupData.indices : undefined}
-            checkupLabel={intl.formatMessage({
-              id: 'xpack.upgradeAssistant.checkupTab.indexLabel',
+            checkupLabel={i18n.translate('xpack.upgradeAssistant.checkupTab.indexLabel', {
               defaultMessage: 'index',
             })}
             showBackupWarning
@@ -249,5 +246,3 @@ export class UpgradeAssistantTabsUI extends React.Component<Props, TabsState> {
     this.setState({ telemetryState: TelemetryState.Complete });
   }
 }
-
-export const UpgradeAssistantTabs = injectI18n(UpgradeAssistantTabsUI);
diff --git a/x-pack/plugins/upgrade_assistant/public/application/components/tabs/checkup/deprecations/cell.tsx b/x-pack/plugins/upgrade_assistant/public/application/components/tabs/checkup/deprecations/cell.tsx
index 879bb695ca60af..6eaa0de530673f 100644
--- a/x-pack/plugins/upgrade_assistant/public/application/components/tabs/checkup/deprecations/cell.tsx
+++ b/x-pack/plugins/upgrade_assistant/public/application/components/tabs/checkup/deprecations/cell.tsx
@@ -18,6 +18,7 @@ import {
 import { FormattedMessage } from '@kbn/i18n/react';
 import { ReindexButton } from './reindex';
 import { AppContext } from '../../../../app_context';
+import { EnrichedDeprecationInfo } from '../../../../../../common/types';
 
 interface DeprecationCellProps {
   items?: Array<{ title?: string; body: string }>;
@@ -26,6 +27,7 @@ interface DeprecationCellProps {
   headline?: string;
   healthColor?: string;
   children?: ReactNode;
+  reindexBlocker?: EnrichedDeprecationInfo['blockerForReindexing'];
 }
 
 /**
@@ -38,6 +40,7 @@ export const DeprecationCell: FunctionComponent<DeprecationCellProps> = ({
   docUrl,
   items = [],
   children,
+  reindexBlocker,
 }) => (
   <div className="upgDeprecationCell">
     <EuiFlexGroup responsive={false} wrap alignItems="baseline">
@@ -79,7 +82,14 @@ export const DeprecationCell: FunctionComponent<DeprecationCellProps> = ({
       {reindexIndexName && (
         <EuiFlexItem grow={false}>
           <AppContext.Consumer>
-            {({ http }) => <ReindexButton indexName={reindexIndexName} http={http} />}
+            {({ http, docLinks }) => (
+              <ReindexButton
+                docLinks={docLinks}
+                reindexBlocker={reindexBlocker}
+                indexName={reindexIndexName}
+                http={http}
+              />
+            )}
           </AppContext.Consumer>
         </EuiFlexItem>
       )}
diff --git a/x-pack/plugins/upgrade_assistant/public/application/components/tabs/checkup/deprecations/index_table.tsx b/x-pack/plugins/upgrade_assistant/public/application/components/tabs/checkup/deprecations/index_table.tsx
index 5506528a3ded09..19767c34a1b064 100644
--- a/x-pack/plugins/upgrade_assistant/public/application/components/tabs/checkup/deprecations/index_table.tsx
+++ b/x-pack/plugins/upgrade_assistant/public/application/components/tabs/checkup/deprecations/index_table.tsx
@@ -11,12 +11,14 @@ import { EuiBasicTable } from '@elastic/eui';
 import { injectI18n } from '@kbn/i18n/react';
 import { ReindexButton } from './reindex';
 import { AppContext } from '../../../../app_context';
+import { EnrichedDeprecationInfo } from '../../../../../../common/types';
 
 const PAGE_SIZES = [10, 25, 50, 100, 250, 500, 1000];
 
 export interface IndexDeprecationDetails {
   index: string;
   reindex: boolean;
+  blockerForReindexing?: EnrichedDeprecationInfo['blockerForReindexing'];
   details?: string;
 }
 
@@ -68,9 +70,10 @@ export class IndexDeprecationTableUI extends React.Component<
       },
     ];
 
-    if (this.actionsColumn) {
-      // @ts-ignore
-      columns.push(this.actionsColumn);
+    const actionsColumn = this.generateActionsColumn();
+
+    if (actionsColumn) {
+      columns.push(actionsColumn as any);
     }
 
     const sorting = {
@@ -134,7 +137,7 @@ export class IndexDeprecationTableUI extends React.Component<
     return { totalItemCount, pageSizeOptions, hidePerPageOptions: false };
   }
 
-  private get actionsColumn() {
+  private generateActionsColumn() {
     // NOTE: this naive implementation assumes all indices in the table are
     // should show the reindex button. This should work for known usecases.
     const { indices } = this.props;
@@ -148,7 +151,16 @@ export class IndexDeprecationTableUI extends React.Component<
           render(indexDep: IndexDeprecationDetails) {
             return (
               <AppContext.Consumer>
-                {({ http }) => <ReindexButton indexName={indexDep.index!} http={http} />}
+                {({ http, docLinks }) => {
+                  return (
+                    <ReindexButton
+                      docLinks={docLinks}
+                      reindexBlocker={indexDep.blockerForReindexing}
+                      indexName={indexDep.index!}
+                      http={http}
+                    />
+                  );
+                }}
               </AppContext.Consumer>
             );
           },
diff --git a/x-pack/plugins/upgrade_assistant/public/application/components/tabs/checkup/deprecations/list.test.tsx b/x-pack/plugins/upgrade_assistant/public/application/components/tabs/checkup/deprecations/list.test.tsx
index a1e173737bab06..606faf52b8e2bd 100644
--- a/x-pack/plugins/upgrade_assistant/public/application/components/tabs/checkup/deprecations/list.test.tsx
+++ b/x-pack/plugins/upgrade_assistant/public/application/components/tabs/checkup/deprecations/list.test.tsx
@@ -23,29 +23,29 @@ describe('DeprecationList', () => {
 
     test('shows simple messages when index field is not present', () => {
       expect(shallow(<DeprecationList {...defaultProps} />)).toMatchInlineSnapshot(`
-<div>
-  <SimpleMessageDeprecation
-    deprecation={
-      Object {
-        "level": "warning",
-        "message": "Issue 1",
-        "url": "",
-      }
-    }
-    key="Issue 1"
-  />
-  <SimpleMessageDeprecation
-    deprecation={
-      Object {
-        "level": "warning",
-        "message": "Issue 1",
-        "url": "",
-      }
-    }
-    key="Issue 1"
-  />
-</div>
-`);
+        <div>
+          <SimpleMessageDeprecation
+            deprecation={
+              Object {
+                "level": "warning",
+                "message": "Issue 1",
+                "url": "",
+              }
+            }
+            key="Issue 1"
+          />
+          <SimpleMessageDeprecation
+            deprecation={
+              Object {
+                "level": "warning",
+                "message": "Issue 1",
+                "url": "",
+              }
+            }
+            key="Issue 1"
+          />
+        </div>
+      `);
     });
 
     test('shows index deprecation when index field is present', () => {
@@ -59,31 +59,33 @@ describe('DeprecationList', () => {
       };
       const wrapper = shallow(<DeprecationList {...props} />);
       expect(wrapper).toMatchInlineSnapshot(`
-<IndexDeprecation
-  deprecation={
-    Object {
-      "index": "0",
-      "level": "warning",
-      "message": "Issue 1",
-      "url": "",
-    }
-  }
-  indices={
-    Array [
-      Object {
-        "details": undefined,
-        "index": "0",
-        "reindex": false,
-      },
-      Object {
-        "details": undefined,
-        "index": "1",
-        "reindex": false,
-      },
-    ]
-  }
-/>
-`);
+        <IndexDeprecation
+          deprecation={
+            Object {
+              "index": "0",
+              "level": "warning",
+              "message": "Issue 1",
+              "url": "",
+            }
+          }
+          indices={
+            Array [
+              Object {
+                "blockerForReindexing": undefined,
+                "details": undefined,
+                "index": "0",
+                "reindex": false,
+              },
+              Object {
+                "blockerForReindexing": undefined,
+                "details": undefined,
+                "index": "1",
+                "reindex": false,
+              },
+            ]
+          }
+        />
+      `);
     });
   });
 
@@ -98,31 +100,31 @@ describe('DeprecationList', () => {
 
     test('shows detailed messages', () => {
       expect(shallow(<DeprecationList {...defaultProps} />)).toMatchInlineSnapshot(`
-<div>
-  <MessageDeprecation
-    deprecation={
-      Object {
-        "index": "index1",
-        "level": "warning",
-        "message": "Issue 1",
-        "url": "",
-      }
-    }
-    key="Issue 1"
-  />
-  <MessageDeprecation
-    deprecation={
-      Object {
-        "index": "index1",
-        "level": "warning",
-        "message": "Issue 2",
-        "url": "",
-      }
-    }
-    key="Issue 2"
-  />
-</div>
-`);
+        <div>
+          <MessageDeprecation
+            deprecation={
+              Object {
+                "index": "index1",
+                "level": "warning",
+                "message": "Issue 1",
+                "url": "",
+              }
+            }
+            key="Issue 1"
+          />
+          <MessageDeprecation
+            deprecation={
+              Object {
+                "index": "index1",
+                "level": "warning",
+                "message": "Issue 2",
+                "url": "",
+              }
+            }
+            key="Issue 2"
+          />
+        </div>
+      `);
     });
   });
 });
diff --git a/x-pack/plugins/upgrade_assistant/public/application/components/tabs/checkup/deprecations/list.tsx b/x-pack/plugins/upgrade_assistant/public/application/components/tabs/checkup/deprecations/list.tsx
index a46bc0d12fad41..ab71972f361ea2 100644
--- a/x-pack/plugins/upgrade_assistant/public/application/components/tabs/checkup/deprecations/list.tsx
+++ b/x-pack/plugins/upgrade_assistant/public/application/components/tabs/checkup/deprecations/list.tsx
@@ -32,6 +32,7 @@ const MessageDeprecation: FunctionComponent<{ deprecation: EnrichedDeprecationIn
 
   return (
     <DeprecationCell
+      reindexBlocker={deprecation.blockerForReindexing}
       headline={deprecation.message}
       healthColor={COLOR_MAP[deprecation.level]}
       reindexIndexName={deprecation.reindex ? deprecation.index! : undefined}
@@ -53,7 +54,13 @@ const SimpleMessageDeprecation: FunctionComponent<{ deprecation: EnrichedDepreca
     items.push({ body: deprecation.details });
   }
 
-  return <DeprecationCell items={items} docUrl={deprecation.url} />;
+  return (
+    <DeprecationCell
+      reindexBlocker={deprecation.blockerForReindexing}
+      items={items}
+      docUrl={deprecation.url}
+    />
+  );
 };
 
 interface IndexDeprecationProps {
@@ -89,6 +96,7 @@ export const DeprecationList: FunctionComponent<{
       index: dep.index!,
       details: dep.details,
       reindex: dep.reindex === true,
+      blockerForReindexing: dep.blockerForReindexing,
     }));
     return <IndexDeprecation indices={indices} deprecation={deprecations[0]} />;
   } else if (currentGroupBy === GroupByOption.index) {
diff --git a/x-pack/plugins/upgrade_assistant/public/application/components/tabs/checkup/deprecations/reindex/button.tsx b/x-pack/plugins/upgrade_assistant/public/application/components/tabs/checkup/deprecations/reindex/button.tsx
index 30b46e0c15213e..3738e265515a0d 100644
--- a/x-pack/plugins/upgrade_assistant/public/application/components/tabs/checkup/deprecations/reindex/button.tsx
+++ b/x-pack/plugins/upgrade_assistant/public/application/components/tabs/checkup/deprecations/reindex/button.tsx
@@ -6,12 +6,17 @@
 
 import { set } from 'lodash';
 import React, { Fragment, ReactNode } from 'react';
+import { i18n } from '@kbn/i18n';
 import { Subscription } from 'rxjs';
 
-import { EuiButton, EuiLoadingSpinner } from '@elastic/eui';
+import { EuiButton, EuiLoadingSpinner, EuiText, EuiToolTip } from '@elastic/eui';
 import { FormattedMessage } from '@kbn/i18n/react';
-import { HttpSetup } from 'src/core/public';
-import { ReindexStatus, UIReindexOption } from '../../../../../../../common/types';
+import { DocLinksStart, HttpSetup } from 'src/core/public';
+import {
+  EnrichedDeprecationInfo,
+  ReindexStatus,
+  UIReindexOption,
+} from '../../../../../../../common/types';
 import { LoadingState } from '../../../../types';
 import { ReindexFlyout } from './flyout';
 import { ReindexPollingService, ReindexState } from './polling_service';
@@ -19,6 +24,8 @@ import { ReindexPollingService, ReindexState } from './polling_service';
 interface ReindexButtonProps {
   indexName: string;
   http: HttpSetup;
+  docLinks: DocLinksStart;
+  reindexBlocker?: EnrichedDeprecationInfo['blockerForReindexing'];
 }
 
 interface ReindexButtonState {
@@ -61,7 +68,7 @@ export class ReindexButton extends React.Component<ReindexButtonProps, ReindexBu
   }
 
   public render() {
-    const { indexName } = this.props;
+    const { indexName, reindexBlocker, docLinks } = this.props;
     const { flyoutVisible, reindexState } = this.state;
 
     const buttonProps: any = { size: 's', onClick: this.showFlyout };
@@ -135,12 +142,44 @@ export class ReindexButton extends React.Component<ReindexButtonProps, ReindexBu
       }
     }
 
+    const showIndexedClosedWarning =
+      reindexBlocker === 'index-closed' && reindexState.status !== ReindexStatus.completed;
+
+    if (showIndexedClosedWarning) {
+      buttonProps.color = 'warning';
+      buttonProps.iconType = 'alert';
+    }
+
+    const button = <EuiButton {...buttonProps}>{buttonContent}</EuiButton>;
+
     return (
       <Fragment>
-        <EuiButton {...buttonProps}>{buttonContent}</EuiButton>
+        {showIndexedClosedWarning ? (
+          <EuiToolTip
+            position="top"
+            content={
+              <EuiText size="s">
+                {i18n.translate(
+                  'xpack.upgradeAssistant.checkupTab.reindexing.reindexButton.indexClosedToolTipDetails',
+                  {
+                    defaultMessage:
+                      '"{indexName}" needs to be reindexed, but it is currently closed. The Upgrade Assistant will open, reindex and then close the index. Reindexing may take longer than usual.',
+                    values: { indexName },
+                  }
+                )}
+              </EuiText>
+            }
+          >
+            {button}
+          </EuiToolTip>
+        ) : (
+          button
+        )}
 
         {flyoutVisible && (
           <ReindexFlyout
+            reindexBlocker={reindexBlocker}
+            docLinks={docLinks}
             indexName={indexName}
             closeFlyout={this.closeFlyout}
             reindexState={reindexState}
diff --git a/x-pack/plugins/upgrade_assistant/public/application/components/tabs/checkup/deprecations/reindex/flyout/checklist_step.test.tsx b/x-pack/plugins/upgrade_assistant/public/application/components/tabs/checkup/deprecations/reindex/flyout/checklist_step.test.tsx
index b3eefd40f65e4a..b550063af4fe31 100644
--- a/x-pack/plugins/upgrade_assistant/public/application/components/tabs/checkup/deprecations/reindex/flyout/checklist_step.test.tsx
+++ b/x-pack/plugins/upgrade_assistant/public/application/components/tabs/checkup/deprecations/reindex/flyout/checklist_step.test.tsx
@@ -21,6 +21,7 @@ describe('ChecklistFlyout', () => {
     onConfirmInputChange: jest.fn(),
     startReindex: jest.fn(),
     cancelReindex: jest.fn(),
+    renderGlobalCallouts: jest.fn(),
     reindexState: {
       loadingState: LoadingState.Success,
       lastCompletedStep: undefined,
diff --git a/x-pack/plugins/upgrade_assistant/public/application/components/tabs/checkup/deprecations/reindex/flyout/checklist_step.tsx b/x-pack/plugins/upgrade_assistant/public/application/components/tabs/checkup/deprecations/reindex/flyout/checklist_step.tsx
index e1b8f297570781..31ddaba99a896c 100644
--- a/x-pack/plugins/upgrade_assistant/public/application/components/tabs/checkup/deprecations/reindex/flyout/checklist_step.tsx
+++ b/x-pack/plugins/upgrade_assistant/public/application/components/tabs/checkup/deprecations/reindex/flyout/checklist_step.tsx
@@ -68,17 +68,19 @@ const buttonLabel = (status?: ReindexStatus) => {
  * Displays a flyout that shows the current reindexing status for a given index.
  */
 export const ChecklistFlyoutStep: React.FunctionComponent<{
+  renderGlobalCallouts: () => React.ReactNode;
   closeFlyout: () => void;
   reindexState: ReindexState;
   startReindex: () => void;
   cancelReindex: () => void;
-}> = ({ closeFlyout, reindexState, startReindex, cancelReindex }) => {
+}> = ({ closeFlyout, reindexState, startReindex, cancelReindex, renderGlobalCallouts }) => {
   const { loadingState, status, hasRequiredPrivileges } = reindexState;
   const loading = loadingState === LoadingState.Loading || status === ReindexStatus.inProgress;
 
   return (
     <Fragment>
       <EuiFlyoutBody>
+        {renderGlobalCallouts()}
         <EuiCallOut
           title={
             <FormattedMessage
diff --git a/x-pack/plugins/upgrade_assistant/public/application/components/tabs/checkup/deprecations/reindex/flyout/container.tsx b/x-pack/plugins/upgrade_assistant/public/application/components/tabs/checkup/deprecations/reindex/flyout/container.tsx
index fa619140bcd160..be4138b7a29f36 100644
--- a/x-pack/plugins/upgrade_assistant/public/application/components/tabs/checkup/deprecations/reindex/flyout/container.tsx
+++ b/x-pack/plugins/upgrade_assistant/public/application/components/tabs/checkup/deprecations/reindex/flyout/container.tsx
@@ -5,9 +5,20 @@
  */
 
 import React from 'react';
-
-import { EuiFlyout, EuiFlyoutHeader, EuiPortal, EuiTitle } from '@elastic/eui';
+import { DocLinksStart } from 'kibana/public';
+import { i18n } from '@kbn/i18n';
 import { FormattedMessage } from '@kbn/i18n/react';
+import {
+  EuiCallOut,
+  EuiFlyout,
+  EuiFlyoutHeader,
+  EuiLink,
+  EuiPortal,
+  EuiSpacer,
+  EuiTitle,
+} from '@elastic/eui';
+
+import { EnrichedDeprecationInfo, ReindexStatus } from '../../../../../../../../common/types';
 
 import { ReindexState } from '../polling_service';
 import { ChecklistFlyoutStep } from './checklist_step';
@@ -24,12 +35,58 @@ interface ReindexFlyoutProps {
   reindexState: ReindexState;
   startReindex: () => void;
   cancelReindex: () => void;
+  docLinks: DocLinksStart;
+  reindexBlocker?: EnrichedDeprecationInfo['blockerForReindexing'];
 }
 
 interface ReindexFlyoutState {
   currentFlyoutStep: ReindexFlyoutStep;
 }
 
+const getOpenAndCloseIndexDocLink = ({ ELASTIC_WEBSITE_URL, DOC_LINK_VERSION }: DocLinksStart) => (
+  <EuiLink
+    target="_blank"
+    href={`${ELASTIC_WEBSITE_URL}/guide/en/elasticsearch/reference/${DOC_LINK_VERSION}/indices-open-close.html`}
+  >
+    {i18n.translate(
+      'xpack.upgradeAssistant.checkupTab.reindexing.flyout.openAndCloseDocumentation',
+      { defaultMessage: 'documentation' }
+    )}
+  </EuiLink>
+);
+
+const getIndexClosedCallout = (docLinks: DocLinksStart) => (
+  <>
+    <EuiCallOut
+      title={i18n.translate(
+        'xpack.upgradeAssistant.checkupTab.reindexing.flyout.indexClosedCallout.calloutTitle',
+        { defaultMessage: 'Index closed' }
+      )}
+      color="warning"
+      iconType="alert"
+    >
+      <p>
+        <FormattedMessage
+          id="xpack.upgradeAssistant.checkupTab.reindexing.flyout.indexClosedCallout.calloutDetails"
+          defaultMessage="This index is currently closed. The Upgrade Assistant will open, reindex and then close the index. {reindexingMayTakeLongerEmph}. Please see the {docs} for more information."
+          values={{
+            docs: getOpenAndCloseIndexDocLink(docLinks),
+            reindexingMayTakeLongerEmph: (
+              <b>
+                {i18n.translate(
+                  'xpack.upgradeAssistant.checkupTab.reindexing.flyout.indexClosedCallout.calloutDetails.reindexingTakesLongerEmphasis',
+                  { defaultMessage: 'Reindexing may take longer than usual' }
+                )}
+              </b>
+            ),
+          }}
+        />
+      </p>
+    </EuiCallOut>
+    <EuiSpacer size="m" />
+  </>
+);
+
 /**
  * Wrapper for the contents of the flyout that manages which step of the flyout to show.
  */
@@ -48,14 +105,28 @@ export class ReindexFlyout extends React.Component<ReindexFlyoutProps, ReindexFl
   }
 
   public render() {
-    const { closeFlyout, indexName, reindexState, startReindex, cancelReindex } = this.props;
+    const {
+      closeFlyout,
+      indexName,
+      reindexState,
+      startReindex,
+      cancelReindex,
+      reindexBlocker,
+      docLinks,
+    } = this.props;
     const { currentFlyoutStep } = this.state;
 
     let flyoutContents: React.ReactNode;
+
+    const globalCallout =
+      reindexBlocker === 'index-closed' && reindexState.status !== ReindexStatus.completed
+        ? getIndexClosedCallout(docLinks)
+        : undefined;
     switch (currentFlyoutStep) {
       case ReindexFlyoutStep.reindexWarnings:
         flyoutContents = (
           <WarningsFlyoutStep
+            renderGlobalCallouts={() => globalCallout}
             closeFlyout={closeFlyout}
             warnings={reindexState.reindexWarnings!}
             advanceNextStep={this.advanceNextStep}
@@ -65,6 +136,7 @@ export class ReindexFlyout extends React.Component<ReindexFlyoutProps, ReindexFl
       case ReindexFlyoutStep.checklist:
         flyoutContents = (
           <ChecklistFlyoutStep
+            renderGlobalCallouts={() => globalCallout}
             closeFlyout={closeFlyout}
             reindexState={reindexState}
             startReindex={startReindex}
diff --git a/x-pack/plugins/upgrade_assistant/public/application/components/tabs/checkup/deprecations/reindex/flyout/warning_step.test.tsx b/x-pack/plugins/upgrade_assistant/public/application/components/tabs/checkup/deprecations/reindex/flyout/warning_step.test.tsx
index fddbe84e284616..318d2bc7baffef 100644
--- a/x-pack/plugins/upgrade_assistant/public/application/components/tabs/checkup/deprecations/reindex/flyout/warning_step.test.tsx
+++ b/x-pack/plugins/upgrade_assistant/public/application/components/tabs/checkup/deprecations/reindex/flyout/warning_step.test.tsx
@@ -16,6 +16,7 @@ describe('WarningsFlyoutStep', () => {
     advanceNextStep: jest.fn(),
     warnings: [ReindexWarning.allField, ReindexWarning.booleanFields],
     closeFlyout: jest.fn(),
+    renderGlobalCallouts: jest.fn(),
   };
 
   it('renders', () => {
diff --git a/x-pack/plugins/upgrade_assistant/public/application/components/tabs/checkup/deprecations/reindex/flyout/warnings_step.tsx b/x-pack/plugins/upgrade_assistant/public/application/components/tabs/checkup/deprecations/reindex/flyout/warnings_step.tsx
index 643dd2e9b6efc6..4e296aca3d0b70 100644
--- a/x-pack/plugins/upgrade_assistant/public/application/components/tabs/checkup/deprecations/reindex/flyout/warnings_step.tsx
+++ b/x-pack/plugins/upgrade_assistant/public/application/components/tabs/checkup/deprecations/reindex/flyout/warnings_step.tsx
@@ -62,6 +62,7 @@ const WarningCheckbox: React.FunctionComponent<{
 );
 
 interface WarningsConfirmationFlyoutProps {
+  renderGlobalCallouts: () => React.ReactNode;
   closeFlyout: () => void;
   warnings: ReindexWarning[];
   advanceNextStep: () => void;
@@ -91,7 +92,7 @@ export class WarningsFlyoutStep extends React.Component<
   }
 
   public render() {
-    const { warnings, closeFlyout, advanceNextStep } = this.props;
+    const { warnings, closeFlyout, advanceNextStep, renderGlobalCallouts } = this.props;
     const { checkedIds } = this.state;
 
     // Do not allow to proceed until all checkboxes are checked.
@@ -100,6 +101,7 @@ export class WarningsFlyoutStep extends React.Component<
     return (
       <Fragment>
         <EuiFlyoutBody>
+          {renderGlobalCallouts()}
           <EuiCallOut
             title={
               <FormattedMessage
diff --git a/x-pack/plugins/upgrade_assistant/public/application/components/tabs/checkup/deprecations/reindex/polling_service.ts b/x-pack/plugins/upgrade_assistant/public/application/components/tabs/checkup/deprecations/reindex/polling_service.ts
index 6fe6a859057062..bcd3abb98f8d4d 100644
--- a/x-pack/plugins/upgrade_assistant/public/application/components/tabs/checkup/deprecations/reindex/polling_service.ts
+++ b/x-pack/plugins/upgrade_assistant/public/application/components/tabs/checkup/deprecations/reindex/polling_service.ts
@@ -94,6 +94,7 @@ export class ReindexPollingService {
         errorMessage: null,
         cancelLoadingState: undefined,
       });
+
       const data = await this.http.post<ReindexOperation>(
         `/api/upgrade_assistant/reindex/${this.indexName}`
       );
diff --git a/x-pack/plugins/upgrade_assistant/public/plugin.ts b/x-pack/plugins/upgrade_assistant/public/plugin.ts
index 614221272dd5c4..300da4eccae156 100644
--- a/x-pack/plugins/upgrade_assistant/public/plugin.ts
+++ b/x-pack/plugins/upgrade_assistant/public/plugin.ts
@@ -37,8 +37,8 @@ export class UpgradeAssistantUIPlugin implements Plugin {
       }),
       order: 1000,
       async mount({ element }) {
-        const [{ i18n: i18nDep }] = await getStartServices();
-        return renderApp({ element, isCloudEnabled, http, i18n: i18nDep });
+        const [{ i18n: i18nDep, docLinks }] = await getStartServices();
+        return renderApp({ element, isCloudEnabled, http, i18n: i18nDep, docLinks });
       },
     });
   }
diff --git a/x-pack/plugins/upgrade_assistant/server/lib/__snapshots__/es_migration_apis.test.ts.snap b/x-pack/plugins/upgrade_assistant/server/lib/__snapshots__/es_migration_apis.test.ts.snap
index 10f66fd1fc01ac..244fc96acd1943 100644
--- a/x-pack/plugins/upgrade_assistant/server/lib/__snapshots__/es_migration_apis.test.ts.snap
+++ b/x-pack/plugins/upgrade_assistant/server/lib/__snapshots__/es_migration_apis.test.ts.snap
@@ -30,6 +30,7 @@ Object {
   ],
   "indices": Array [
     Object {
+      "blockerForReindexing": undefined,
       "details": "[[type: doc, field: spins], [type: doc, field: mlockall], [type: doc, field: node_master], [type: doc, field: primary]]",
       "index": ".monitoring-es-6-2018.11.07",
       "level": "warning",
@@ -38,6 +39,7 @@ Object {
       "url": "https://www.elastic.co/guide/en/elasticsearch/reference/6.0/breaking_60_mappings_changes.html#_coercion_of_boolean_fields",
     },
     Object {
+      "blockerForReindexing": undefined,
       "details": "[[type: tweet, field: liked]]",
       "index": "twitter",
       "level": "warning",
@@ -46,6 +48,7 @@ Object {
       "url": "https://www.elastic.co/guide/en/elasticsearch/reference/6.0/breaking_60_mappings_changes.html#_coercion_of_boolean_fields",
     },
     Object {
+      "blockerForReindexing": undefined,
       "details": "[[type: index-pattern, field: notExpandable], [type: config, field: xPackMonitoring:allowReport], [type: config, field: xPackMonitoring:showBanner], [type: dashboard, field: pause], [type: dashboard, field: timeRestore]]",
       "index": ".kibana",
       "level": "warning",
@@ -54,6 +57,7 @@ Object {
       "url": "https://www.elastic.co/guide/en/elasticsearch/reference/6.0/breaking_60_mappings_changes.html#_coercion_of_boolean_fields",
     },
     Object {
+      "blockerForReindexing": undefined,
       "details": "[[type: doc, field: notify], [type: doc, field: created], [type: doc, field: attach_payload], [type: doc, field: met]]",
       "index": ".watcher-history-6-2018.11.07",
       "level": "warning",
@@ -62,6 +66,7 @@ Object {
       "url": "https://www.elastic.co/guide/en/elasticsearch/reference/6.0/breaking_60_mappings_changes.html#_coercion_of_boolean_fields",
     },
     Object {
+      "blockerForReindexing": undefined,
       "details": "[[type: doc, field: snapshot]]",
       "index": ".monitoring-kibana-6-2018.11.07",
       "level": "warning",
@@ -70,6 +75,7 @@ Object {
       "url": "https://www.elastic.co/guide/en/elasticsearch/reference/6.0/breaking_60_mappings_changes.html#_coercion_of_boolean_fields",
     },
     Object {
+      "blockerForReindexing": undefined,
       "details": "[[type: tweet, field: liked]]",
       "index": "twitter2",
       "level": "warning",
diff --git a/x-pack/plugins/upgrade_assistant/server/lib/es_indices_state_check.ts b/x-pack/plugins/upgrade_assistant/server/lib/es_indices_state_check.ts
new file mode 100644
index 00000000000000..9931abf7f416c4
--- /dev/null
+++ b/x-pack/plugins/upgrade_assistant/server/lib/es_indices_state_check.ts
@@ -0,0 +1,36 @@
+/*
+ * Copyright Elasticsearch B.V. and/or licensed to Elasticsearch B.V. under one
+ * or more contributor license agreements. Licensed under the Elastic License;
+ * you may not use this file except in compliance with the Elastic License.
+ */
+
+import { IScopedClusterClient } from 'kibana/server';
+import { getIndexStateFromClusterState } from '../../common/get_index_state_from_cluster_state';
+import { ClusterStateAPIResponse } from '../../common/types';
+
+type StatusCheckResult = Record<string, 'open' | 'close'>;
+
+export const esIndicesStateCheck = async (
+  dataClient: IScopedClusterClient,
+  indices: string[]
+): Promise<StatusCheckResult> => {
+  // According to https://www.elastic.co/guide/en/elasticsearch/reference/7.6/cluster-state.html
+  // The response from this call is considered internal and subject to change. We have an API
+  // integration test for asserting that the current ES version still returns what we expect.
+  // This lives in x-pack/test/upgrade_assistant_integration
+  const clusterState: ClusterStateAPIResponse = await dataClient.callAsCurrentUser(
+    'cluster.state',
+    {
+      index: indices,
+      metric: 'metadata',
+    }
+  );
+
+  const result: StatusCheckResult = {};
+
+  indices.forEach(index => {
+    result[index] = getIndexStateFromClusterState(index, clusterState);
+  });
+
+  return result;
+};
diff --git a/x-pack/plugins/upgrade_assistant/server/lib/es_migration_apis.test.ts b/x-pack/plugins/upgrade_assistant/server/lib/es_migration_apis.test.ts
index 4ab4227ba3e919..89571a4a18231a 100644
--- a/x-pack/plugins/upgrade_assistant/server/lib/es_migration_apis.test.ts
+++ b/x-pack/plugins/upgrade_assistant/server/lib/es_migration_apis.test.ts
@@ -15,9 +15,24 @@ describe('getUpgradeAssistantStatus', () => {
   let deprecationsResponse: DeprecationAPIResponse;
 
   const dataClient = elasticsearchServiceMock.createScopedClusterClient();
-  (dataClient.callAsCurrentUser as jest.Mock).mockImplementation(async (api, { path }) => {
+  (dataClient.callAsCurrentUser as jest.Mock).mockImplementation(async (api, { path, index }) => {
     if (path === '/_migration/deprecations') {
       return deprecationsResponse;
+    } else if (api === 'cluster.state') {
+      return {
+        metadata: {
+          indices: {
+            ...index.reduce((acc: any, i: any) => {
+              return {
+                ...acc,
+                [i]: {
+                  state: 'open',
+                },
+              };
+            }, {}),
+          },
+        },
+      };
     } else if (api === 'indices.getMapping') {
       return {};
     } else {
diff --git a/x-pack/plugins/upgrade_assistant/server/lib/es_migration_apis.ts b/x-pack/plugins/upgrade_assistant/server/lib/es_migration_apis.ts
index 68f21c1fd93b56..3381e5506f39a6 100644
--- a/x-pack/plugins/upgrade_assistant/server/lib/es_migration_apis.ts
+++ b/x-pack/plugins/upgrade_assistant/server/lib/es_migration_apis.ts
@@ -8,6 +8,8 @@ import { IScopedClusterClient } from 'src/core/server';
 import { DeprecationAPIResponse } from 'src/legacy/core_plugins/elasticsearch';
 import { EnrichedDeprecationInfo, UpgradeAssistantStatus } from '../../common/types';
 
+import { esIndicesStateCheck } from './es_indices_state_check';
+
 export async function getUpgradeAssistantStatus(
   dataClient: IScopedClusterClient,
   isCloudEnabled: boolean
@@ -20,6 +22,19 @@ export async function getUpgradeAssistantStatus(
   const cluster = getClusterDeprecations(deprecations, isCloudEnabled);
   const indices = getCombinedIndexInfos(deprecations);
 
+  const indexNames = indices.map(({ index }) => index!);
+
+  // If we have found deprecation information for index/indices check whether the index is
+  // open or closed.
+  if (indexNames.length) {
+    const indexStates = await esIndicesStateCheck(dataClient, indexNames);
+
+    indices.forEach(indexData => {
+      indexData.blockerForReindexing =
+        indexStates[indexData.index!] === 'close' ? 'index-closed' : undefined;
+    });
+  }
+
   const criticalWarnings = cluster.concat(indices).filter(d => d.level === 'critical');
 
   return {
diff --git a/x-pack/plugins/upgrade_assistant/server/lib/reindexing/index_settings.ts b/x-pack/plugins/upgrade_assistant/server/lib/reindexing/index_settings.ts
index f6dc471d0945d3..5722a6c29b68ff 100644
--- a/x-pack/plugins/upgrade_assistant/server/lib/reindexing/index_settings.ts
+++ b/x-pack/plugins/upgrade_assistant/server/lib/reindexing/index_settings.ts
@@ -88,6 +88,7 @@ const removeUnsettableSettings = (settings: FlatSettings['settings']) =>
     'index.routing.allocation.initial_recovery._id',
     'index.version.created',
     'index.version.upgraded',
+    'index.verified_before_close',
   ]);
 
 // Use `flow` to pipe the settings through each function.
diff --git a/x-pack/plugins/upgrade_assistant/server/lib/reindexing/reindex_actions.test.ts b/x-pack/plugins/upgrade_assistant/server/lib/reindexing/reindex_actions.test.ts
index 4569fdfa33a83b..0a8887083c27e9 100644
--- a/x-pack/plugins/upgrade_assistant/server/lib/reindexing/reindex_actions.test.ts
+++ b/x-pack/plugins/upgrade_assistant/server/lib/reindexing/reindex_actions.test.ts
@@ -51,6 +51,7 @@ describe('ReindexActions', () => {
       expect(client.create).toHaveBeenCalledWith(REINDEX_OP_TYPE, {
         indexName: 'myIndex',
         newIndexName: `reindexed-v${CURRENT_MAJOR_VERSION}-myIndex`,
+        reindexOptions: undefined,
         status: ReindexStatus.inProgress,
         lastCompletedStep: ReindexStep.created,
         locked: null,
@@ -66,6 +67,7 @@ describe('ReindexActions', () => {
       expect(client.create).toHaveBeenCalledWith(REINDEX_OP_TYPE, {
         indexName: '.internalIndex',
         newIndexName: `.reindexed-v${CURRENT_MAJOR_VERSION}-internalIndex`,
+        reindexOptions: undefined,
         status: ReindexStatus.inProgress,
         lastCompletedStep: ReindexStep.created,
         locked: null,
@@ -83,6 +85,7 @@ describe('ReindexActions', () => {
       expect(client.create).toHaveBeenCalledWith(REINDEX_OP_TYPE, {
         indexName,
         newIndexName: `reindexed-v${CURRENT_MAJOR_VERSION}-myIndex`,
+        reindexOptions: undefined,
         status: ReindexStatus.inProgress,
         lastCompletedStep: ReindexStep.created,
         locked: null,
@@ -98,6 +101,7 @@ describe('ReindexActions', () => {
       expect(client.create).toHaveBeenCalledWith(REINDEX_OP_TYPE, {
         indexName: `reindexed-v${PREV_MAJOR_VERSION}-myIndex`,
         newIndexName: `reindexed-v${CURRENT_MAJOR_VERSION}-myIndex`,
+        reindexOptions: undefined,
         status: ReindexStatus.inProgress,
         lastCompletedStep: ReindexStep.created,
         locked: null,
diff --git a/x-pack/plugins/upgrade_assistant/server/lib/reindexing/reindex_actions.ts b/x-pack/plugins/upgrade_assistant/server/lib/reindexing/reindex_actions.ts
index 422e78c2f12ad9..81c8f2563a66d9 100644
--- a/x-pack/plugins/upgrade_assistant/server/lib/reindexing/reindex_actions.ts
+++ b/x-pack/plugins/upgrade_assistant/server/lib/reindexing/reindex_actions.ts
@@ -35,7 +35,7 @@ export interface ReindexActions {
   /**
    * Creates a new reindexOp, does not perform any pre-flight checks.
    * @param indexName
-   * @param opts Options for the reindex operation
+   * @param opts Additional options when creating the reindex operation
    */
   createReindexOp(indexName: string, opts?: ReindexOptions): Promise<ReindexSavedObject>;
 
diff --git a/x-pack/plugins/upgrade_assistant/server/lib/reindexing/reindex_service.test.ts b/x-pack/plugins/upgrade_assistant/server/lib/reindexing/reindex_service.test.ts
index 886ea6761e3b73..beb7b28e05e97b 100644
--- a/x-pack/plugins/upgrade_assistant/server/lib/reindexing/reindex_service.test.ts
+++ b/x-pack/plugins/upgrade_assistant/server/lib/reindexing/reindex_service.test.ts
@@ -841,7 +841,11 @@ describe('reindexService', () => {
     describe('newIndexCreated', () => {
       const reindexOp = {
         id: '1',
-        attributes: { ...defaultAttributes, lastCompletedStep: ReindexStep.newIndexCreated },
+        attributes: {
+          ...defaultAttributes,
+          lastCompletedStep: ReindexStep.newIndexCreated,
+          reindexOptions: { openAndClose: false },
+        },
       } as ReindexSavedObject;
 
       beforeEach(() => {
@@ -957,7 +961,11 @@ describe('reindexService', () => {
     describe('reindexCompleted', () => {
       const reindexOp = {
         id: '1',
-        attributes: { ...defaultAttributes, lastCompletedStep: ReindexStep.reindexCompleted },
+        attributes: {
+          ...defaultAttributes,
+          lastCompletedStep: ReindexStep.reindexCompleted,
+          reindexOptions: { openAndClose: false },
+        },
       } as ReindexSavedObject;
 
       it('switches aliases, sets as complete, and updates lastCompletedStep', async () => {
diff --git a/x-pack/plugins/upgrade_assistant/server/lib/reindexing/reindex_service.ts b/x-pack/plugins/upgrade_assistant/server/lib/reindexing/reindex_service.ts
index aa91b925b744b2..4cc465e1f10b9c 100644
--- a/x-pack/plugins/upgrade_assistant/server/lib/reindexing/reindex_service.ts
+++ b/x-pack/plugins/upgrade_assistant/server/lib/reindexing/reindex_service.ts
@@ -14,6 +14,7 @@ import {
   ReindexStep,
   ReindexWarning,
 } from '../../../common/types';
+
 import {
   generateNewIndexName,
   getReindexWarnings,
@@ -52,7 +53,7 @@ export interface ReindexService {
   /**
    * Creates a new reindex operation for a given index.
    * @param indexName
-   * @param opts
+   * @param opts Additional options when creating a new reindex operation
    */
   createReindexOperation(indexName: string, opts?: ReindexOptions): Promise<ReindexSavedObject>;
 
@@ -314,7 +315,11 @@ export const reindexServiceFactory = (
    * @param reindexOp
    */
   const startReindexing = async (reindexOp: ReindexSavedObject) => {
-    const { indexName } = reindexOp.attributes;
+    const { indexName, reindexOptions } = reindexOp.attributes;
+
+    if (reindexOptions?.openAndClose === true) {
+      await callAsUser('indices.open', { index: indexName });
+    }
 
     const startReindex = (await callAsUser('reindex', {
       refresh: true,
@@ -394,7 +399,7 @@ export const reindexServiceFactory = (
    * @param reindexOp
    */
   const switchAlias = async (reindexOp: ReindexSavedObject) => {
-    const { indexName, newIndexName } = reindexOp.attributes;
+    const { indexName, newIndexName, reindexOptions } = reindexOp.attributes;
 
     const existingAliases = (
       await callAsUser('indices.getAlias', {
@@ -420,6 +425,10 @@ export const reindexServiceFactory = (
       throw error.cannotCreateIndex(`Index aliases could not be created.`);
     }
 
+    if (reindexOptions?.openAndClose === true) {
+      await callAsUser('indices.close', { index: indexName });
+    }
+
     return actions.updateReindexOp(reindexOp, {
       lastCompletedStep: ReindexStep.aliasCreated,
     });
@@ -647,7 +656,7 @@ export const reindexServiceFactory = (
 
         return actions.updateReindexOp(op, {
           status: ReindexStatus.inProgress,
-          reindexOptions: opts,
+          reindexOptions: opts ?? op.attributes.reindexOptions,
         });
       });
     },
diff --git a/x-pack/plugins/upgrade_assistant/server/routes/reindex_indices/reindex_handler.ts b/x-pack/plugins/upgrade_assistant/server/routes/reindex_indices/reindex_handler.ts
index 944b4a225d4425..b7569d86795909 100644
--- a/x-pack/plugins/upgrade_assistant/server/routes/reindex_indices/reindex_handler.ts
+++ b/x-pack/plugins/upgrade_assistant/server/routes/reindex_indices/reindex_handler.ts
@@ -23,7 +23,10 @@ interface ReindexHandlerArgs {
   licensing: LicensingPluginSetup;
   headers: Record<string, any>;
   credentialStore: CredentialStore;
-  enqueue?: boolean;
+  reindexOptions?: {
+    openAndClose?: boolean;
+    enqueue?: boolean;
+  };
 }
 
 export const reindexHandler = async ({
@@ -34,7 +37,7 @@ export const reindexHandler = async ({
   licensing,
   log,
   savedObjects,
-  enqueue,
+  reindexOptions,
 }: ReindexHandlerArgs): Promise<ReindexOperation> => {
   const callAsCurrentUser = dataClient.callAsCurrentUser.bind(dataClient);
   const reindexActions = reindexActionsFactory(savedObjects, callAsCurrentUser);
@@ -51,8 +54,11 @@ export const reindexHandler = async ({
 
   const existingOp = await reindexService.findReindexOperation(indexName);
 
-  const opts: ReindexOptions | undefined = enqueue
-    ? { queueSettings: { queuedAt: Date.now() } }
+  const opts: ReindexOptions | undefined = reindexOptions
+    ? {
+        openAndClose: reindexOptions.openAndClose,
+        queueSettings: reindexOptions.enqueue ? { queuedAt: Date.now() } : undefined,
+      }
     : undefined;
 
   // If the reindexOp already exists and it's paused, resume it. Otherwise create a new one.
diff --git a/x-pack/plugins/upgrade_assistant/server/routes/reindex_indices/reindex_indices.test.ts b/x-pack/plugins/upgrade_assistant/server/routes/reindex_indices/reindex_indices.test.ts
index af4f7f436ec811..dc1516ad765609 100644
--- a/x-pack/plugins/upgrade_assistant/server/routes/reindex_indices/reindex_indices.test.ts
+++ b/x-pack/plugins/upgrade_assistant/server/routes/reindex_indices/reindex_indices.test.ts
@@ -20,7 +20,7 @@ const mockReindexService = {
   resumeReindexOperation: jest.fn(),
   cancelReindexing: jest.fn(),
 };
-
+jest.mock('../../lib/es_indices_state_check', () => ({ esIndicesStateCheck: jest.fn() }));
 jest.mock('../../lib/es_version_precheck', () => ({
   versionCheckHandlerWrapper: (a: any) => a,
 }));
@@ -39,6 +39,7 @@ import {
 } from '../../../common/types';
 import { credentialStoreFactory } from '../../lib/reindexing/credential_store';
 import { registerReindexIndicesRoutes } from './reindex_indices';
+import { esIndicesStateCheck } from '../../lib/es_indices_state_check';
 
 /**
  * Since these route callbacks are so thin, these serve simply as integration tests
@@ -56,6 +57,7 @@ describe('reindex API', () => {
   } as any;
 
   beforeEach(() => {
+    (esIndicesStateCheck as jest.Mock).mockResolvedValue({});
     mockRouter = createMockRouter();
     routeDependencies = {
       credentialStore,
@@ -166,7 +168,9 @@ describe('reindex API', () => {
       );
 
       // It called create correctly
-      expect(mockReindexService.createReindexOperation).toHaveBeenCalledWith('theIndex', undefined);
+      expect(mockReindexService.createReindexOperation).toHaveBeenCalledWith('theIndex', {
+        openAndClose: false,
+      });
 
       // It returned the right results
       expect(resp.status).toEqual(200);
@@ -233,7 +237,10 @@ describe('reindex API', () => {
         kibanaResponseFactory
       );
       // It called resume correctly
-      expect(mockReindexService.resumeReindexOperation).toHaveBeenCalledWith('theIndex', undefined);
+      expect(mockReindexService.resumeReindexOperation).toHaveBeenCalledWith('theIndex', {
+        openAndClose: false,
+        queueSettings: undefined,
+      });
       expect(mockReindexService.createReindexOperation).not.toHaveBeenCalled();
 
       // It returned the right results
@@ -262,6 +269,7 @@ describe('reindex API', () => {
 
   describe('POST /api/upgrade_assistant/reindex/batch', () => {
     const queueSettingsArg = {
+      openAndClose: false,
       queueSettings: { queuedAt: expect.any(Number) },
     };
     it('creates a collection of index operations', async () => {
diff --git a/x-pack/plugins/upgrade_assistant/server/routes/reindex_indices/reindex_indices.ts b/x-pack/plugins/upgrade_assistant/server/routes/reindex_indices/reindex_indices.ts
index 697b73d8e10f68..0846e6c0d31d3b 100644
--- a/x-pack/plugins/upgrade_assistant/server/routes/reindex_indices/reindex_indices.ts
+++ b/x-pack/plugins/upgrade_assistant/server/routes/reindex_indices/reindex_indices.ts
@@ -16,6 +16,7 @@ import { LicensingPluginSetup } from '../../../../licensing/server';
 import { ReindexStatus } from '../../../common/types';
 
 import { versionCheckHandlerWrapper } from '../../lib/es_version_precheck';
+import { esIndicesStateCheck } from '../../lib/es_indices_state_check';
 import { reindexServiceFactory, ReindexWorker } from '../../lib/reindexing';
 import { CredentialStore } from '../../lib/reindexing/credential_store';
 import { reindexActionsFactory } from '../../lib/reindexing/reindex_actions';
@@ -107,6 +108,7 @@ export function registerReindexIndicesRoutes(
         response
       ) => {
         const { indexName } = request.params;
+        const indexStates = await esIndicesStateCheck(dataClient, [indexName]);
         try {
           const result = await reindexHandler({
             savedObjects: savedObjectsClient,
@@ -116,6 +118,7 @@ export function registerReindexIndicesRoutes(
             licensing,
             headers: request.headers,
             credentialStore,
+            reindexOptions: { openAndClose: indexStates[indexName] === 'close' },
           });
 
           // Kick the worker on this node to immediately pickup the new reindex operation.
@@ -187,6 +190,7 @@ export function registerReindexIndicesRoutes(
         response
       ) => {
         const { indexNames } = request.body;
+        const indexStates = await esIndicesStateCheck(dataClient, indexNames);
         const results: PostBatchResponse = {
           enqueued: [],
           errors: [],
@@ -201,7 +205,10 @@ export function registerReindexIndicesRoutes(
               licensing,
               headers: request.headers,
               credentialStore,
-              enqueue: true,
+              reindexOptions: {
+                openAndClose: indexStates[indexName] === 'close',
+                enqueue: true,
+              },
             });
             results.enqueued.push(result);
           } catch (e) {
diff --git a/x-pack/test/upgrade_assistant_integration/upgrade_assistant/index.js b/x-pack/test/upgrade_assistant_integration/upgrade_assistant/index.js
index 196e06a61833b9..fa8c3fd99f71d6 100644
--- a/x-pack/test/upgrade_assistant_integration/upgrade_assistant/index.js
+++ b/x-pack/test/upgrade_assistant_integration/upgrade_assistant/index.js
@@ -9,5 +9,6 @@ export default function({ loadTestFile }) {
     this.tags('ciGroup7');
 
     loadTestFile(require.resolve('./reindexing'));
+    loadTestFile(require.resolve('./status'));
   });
 }
diff --git a/x-pack/test/upgrade_assistant_integration/upgrade_assistant/reindexing.js b/x-pack/test/upgrade_assistant_integration/upgrade_assistant/reindexing.js
index a99c02ffef23e7..d2cae9830d31ad 100644
--- a/x-pack/test/upgrade_assistant_integration/upgrade_assistant/reindexing.js
+++ b/x-pack/test/upgrade_assistant_integration/upgrade_assistant/reindexing.js
@@ -8,6 +8,7 @@ import expect from '@kbn/expect';
 
 import { ReindexStatus, REINDEX_OP_TYPE } from '../../../plugins/upgrade_assistant/common/types';
 import { generateNewIndexName } from '../../../plugins/upgrade_assistant/server/lib/reindexing/index_settings';
+import { getIndexStateFromClusterState } from '../../../plugins/upgrade_assistant/common/get_index_state_from_cluster_state';
 
 export default function({ getService }) {
   const supertest = getService('supertest');
@@ -178,6 +179,8 @@ export default function({ getService }) {
         await es.indices.create({ index: test2 });
         await es.indices.create({ index: test3 });
 
+        await es.indices.close({ index: test1 });
+
         const result = await supertest
           .post(`/api/upgrade_assistant/reindex/batch`)
           .set('kbn-xsrf', 'xxx')
@@ -187,6 +190,8 @@ export default function({ getService }) {
         expect(result.body.enqueued.length).to.equal(3);
         expect(result.body.errors.length).to.equal(0);
 
+        const [{ newIndexName: newTest1Name }] = result.body.enqueued;
+
         await assertQueueState(test1, 3);
         await waitForReindexToComplete(test1);
 
@@ -197,6 +202,18 @@ export default function({ getService }) {
         await waitForReindexToComplete(test3);
 
         await assertQueueState(undefined, 0);
+
+        // Check that the closed index is still closed after reindexing
+        const clusterStateResponse = await es.cluster.state({
+          index: newTest1Name,
+          metric: 'metadata',
+        });
+
+        const test1ReindexedState = getIndexStateFromClusterState(
+          newTest1Name,
+          clusterStateResponse
+        );
+        expect(test1ReindexedState).to.be('close');
       } finally {
         await cleanupReindex(test1);
         await cleanupReindex(test2);
diff --git a/x-pack/test/upgrade_assistant_integration/upgrade_assistant/status.ts b/x-pack/test/upgrade_assistant_integration/upgrade_assistant/status.ts
new file mode 100644
index 00000000000000..f38130aa594c19
--- /dev/null
+++ b/x-pack/test/upgrade_assistant_integration/upgrade_assistant/status.ts
@@ -0,0 +1,57 @@
+/*
+ * Copyright Elasticsearch B.V. and/or licensed to Elasticsearch B.V. under one
+ * or more contributor license agreements. Licensed under the Elastic License;
+ * you may not use this file except in compliance with the Elastic License.
+ */
+
+import expect from '@kbn/expect';
+import { FtrProviderContext } from '../../api_integration/ftr_provider_context';
+import { getIndexStateFromClusterState } from '../../../plugins/upgrade_assistant/common/get_index_state_from_cluster_state';
+
+// eslint-disable-next-line import/no-default-export
+export default function({ getService }: FtrProviderContext) {
+  const esArchiver = getService('esArchiver');
+  const es = getService('es');
+
+  describe('status and _cluster/state contract', () => {
+    beforeEach(async () => {
+      await es.indices.open({ index: '7.0-data' });
+    });
+
+    afterEach(async () => {
+      await es.indices.open({ index: '7.0-data' });
+    });
+
+    // According to https://www.elastic.co/guide/en/elasticsearch/reference/7.6/cluster-state.html
+    // The response from this call is considered internal and subject to change. We check that
+    // the contract has not changed in this integration test.
+    it('the _cluster/state endpoint is still what we expect', async () => {
+      await esArchiver.load('upgrade_assistant/reindex');
+      await es.indices.close({ index: '7.0-data' });
+      const result = await es.cluster.state({
+        index: '7.0-data',
+        metric: 'metadata',
+      });
+
+      try {
+        if (getIndexStateFromClusterState('7.0-data', result.body) === 'close') {
+          return;
+        }
+      } catch (e) {
+        expect().fail(
+          `Can no longer access index open/closed state. Please update Upgrade Assistant checkup. (${e.message})`
+        );
+        return;
+      }
+      expect().fail(
+        `The response contract for _cluster/state metadata has changed. Please update Upgrade Assistant checkup. Received ${JSON.stringify(
+          result,
+          null,
+          2
+        )}.
+
+Expected body.metadata.indices['7.0-data'].state to be "close".`
+      );
+    });
+  });
+}