Add refresh, flush, clear cache, and notifications documentation for index management in Dashboards (#4207)

* Add refresh, flush, clear cache, and notifications documentation for index management in Dashboards

Signed-off-by: Fanit Kolchina <kolchfa@amazon.com>

* Tech review comment

Signed-off-by: Fanit Kolchina <kolchfa@amazon.com>

* Implemented tech review comments

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* Apply suggestions from code review

Co-authored-by: suzhou <suzhou@amazon.com>
Signed-off-by: kolchfa-aws <105444904+kolchfa-aws@users.noreply.github.com>

* Updated images

Signed-off-by: Fanit Kolchina <kolchfa@amazon.com>

* Formatting change

Signed-off-by: Fanit Kolchina <kolchfa@amazon.com>

* Implemented tech review comments

Signed-off-by: Fanit Kolchina <kolchfa@amazon.com>

* Apply suggestions from code review

Co-authored-by: Melissa Vagi <vagimeli@amazon.com>
Signed-off-by: kolchfa-aws <105444904+kolchfa-aws@users.noreply.github.com>

* Even spacing

Signed-off-by: Fanit Kolchina <kolchfa@amazon.com>

* Apply suggestions from code review

Co-authored-by: Nathan Bower <nbower@amazon.com>
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* Implemented editorial comments

Signed-off-by: Fanit Kolchina <kolchfa@amazon.com>

---------

Signed-off-by: Fanit Kolchina <kolchfa@amazon.com>
Signed-off-by: kolchfa-aws <105444904+kolchfa-aws@users.noreply.github.com>
Co-authored-by: suzhou <suzhou@amazon.com>
Co-authored-by: Melissa Vagi <vagimeli@amazon.com>
Co-authored-by: Nathan Bower <nbower@amazon.com>

_dashboards/im-dashboards/datastream.md

@@ -91,3 +91,25 @@ To perform a force merge operation on two or more indexes, perform the following
 1. Optionally, under **Advanced settings** you can to choose to **Flush indices** or **Only expunge delete** and then specify the **Max number of segments** to merge to as shown in the following image.
 
     ![Force Merge]({{site.url}}{{site.baseurl}}/images/admin-ui-index/forcemerge2.png)
+
+## Refreshing a data stream
+
+Refreshing a data stream makes new updates to the index visible to search operations. 
+
+The refresh operation can be applied only to open indexes associated with the specified data streams.
+
+To refresh a data stream, select the data stream from the **Data streams** list under **Index Management**. Then select **Refresh** from the **Actions** dropdown list. 
+
+## Flushing a data stream
+
+The flush operation performs a Lucene commit, writing segments to disk and starting a new translog. 
+
+The flush operation can be applied only to open indexes associated with the specified data streams. 
+
+To flush a data stream, select the data stream from the **Data streams** list under **Index Management**. Then select **Flush** from the **Actions** dropdown list. 
+
+## Clearing a data stream cache
+
+The [clear cache operation]({{site.url}}{{site.baseurl}}/api-reference/index-apis/clear-index-cache/) can be applied only to open indexes associated with the specified data streams. 
+
+To clear a data stream cache, select the index from the **Indices** list under **Index Management**. Then select **Clear cache** from the **Actions** dropdown list. 

_dashboards/im-dashboards/index-management.md

@@ -125,6 +125,34 @@ To split an index, select the index you want to split from the **Indices** list
 
 <img src="{{site.url}}{{site.baseurl}}/images/admin-ui-index/split-expanded.png" alt="User interface showing split page">
 
+### Refreshing an index
+
+Refreshing an index makes new updates to the index visible to search operations. 
+
+The refresh operation can be applied only to open indexes. 
+
+To refresh all indexes, select **Refresh** from the **Actions** dropdown list.
+
+To refresh a particular index, select the index from the **Indices** list under **Index Management**. Then select **Refresh** from the **Actions** dropdown list. 
+
+### Flushing an index
+
+The flush operation performs a Lucene commit, writing segments to disk and starting a new translog. 
+
+The flush operation can be applied only to open indexes. 
+
+To flush all indexes, select **Flush** from the **Actions** dropdown list.
+
+To flush a particular index, select the index from the **Indices** list under **Index Management**. Then select **Flush** from the **Actions** dropdown list. 
+
+### Clearing an index cache
+
+The [clear cache operation]({{site.url}}{{site.baseurl}}/api-reference/index-apis/clear-index-cache/) can be applied only to open indexes. 
+
+To clear all index caches, select **Clear cache** from the **Actions** dropdown list.
+
+To clear a particular index cache, select the index from the **Indices** list under **Index Management**. Then select **Clear cache** from the **Actions** dropdown list. 
+
 ### Deleting an index
 
 If you no longer need an index, you can use the [delete index]({{site.url}}{{site.baseurl}}/api-reference/index-apis/delete-index/) operation to delete it.
@@ -170,6 +198,8 @@ An alias is a virtual index name that can point to one or more indexes. If your
 
 <img src="{{site.url}}{{site.baseurl}}/images/admin-ui-index/aliases.PNG" alt="User interface showing Alias page">
 
+### Creating an alias
+
 To create an alias, perform the following steps:
 
 1. Choose the **Create Alias** button on the **Aliases** page under **Index Management**.
@@ -177,7 +207,9 @@ To create an alias, perform the following steps:
 3. Enter the index, or index patterns, to be included in the alias.
 4. Choose **Create alias** as shown in the following image.
 
-<img src="{{site.url}}{{site.baseurl}}/images/admin-ui-index/create-alias.PNG" alt="User interface showing creat Alias page">
+<img src="{{site.url}}{{site.baseurl}}/images/admin-ui-index/create-alias.PNG" alt="User interface showing create Alias page">
+
+### Editing an alias
 
 To edit an alias, perform the following steps:
 
@@ -185,12 +217,36 @@ To edit an alias, perform the following steps:
 2. Choose the **Actions** button.
 3. Choose **Edit** from the dropdown list.
 
+### Deleting an alias
+
 To delete an alias, perform the following steps:
 
 1. Select the alias you want to edit.
 2. Choose the **Actions** button.
 3. Choose **Delete** from the dropdown list.
 
+### Refreshing an alias
+
+Refreshing an alias makes new updates to the index visible to search operations. 
+
+The refresh operation can be applied only to open indexes associated with the specified aliases.
+
+To refresh a particular alias, select the alias from the **Aliases** list under **Index Management**. Then select **Refresh** from the **Actions** dropdown list. 
+
+### Flushing an alias
+
+The flush operation performs a Lucene commit, writing segments to disk and starting a new translog. 
+
+The flush operation can be applied only to open indexes associated with the specified aliases.
+
+To flush an alias, select the alias from the **Aliases** list under **Index Management**. Then select **Flush** from the **Actions** dropdown list. 
+
+### Clearing an alias cache
+
+The [clear cache operation]({{site.url}}{{site.baseurl}}/api-reference/index-apis/clear-index-cache/) can be applied only to open indexes associated with the specified aliases.
+
+To clear an alias cache, select the alias from the **Aliases** list under **Index Management**. Then select **Clear cache** from the **Actions** dropdown list. 
+
 ## Rollup jobs
 
 The **Rollup Jobs** section under **Index Management** allows you to create or update index rollup jobs.

_dashboards/im-dashboards/notifications.md

@@ -0,0 +1,60 @@
+---
+layout: default
+title: Notification settings
+parent: Index management in Dashboards
+nav_order: 60
+---
+
+# Notification settings
+
+You can configure global default notification settings for index operations on the **Notification settings** page. You can also configure additional notification settings for individual index operations.
+
+## Configuring default notification settings
+
+On the **Notification settings** page, you can configure the default notification settings for the following index operations that may take longer to complete:
+
+- Open
+- Reindex
+- Split
+- Shrink
+- Clone
+- Force merge
+
+To get started, select **OpenSearch Plugins** > **Index Management** from the top menu. Under **Index Management**, select **Notification settings**.
+
+You can choose to be notified when the operation has completed or failed. Additionally, you can select the notification channels for this notification, as shown in the following image.
+
+![Default notification settings]({{site.url}}{{site.baseurl}}/images/admin-ui-index/notifications.png)
+
+If you don't have permission to view notification settings, you will not be able to view the default settings. 
+{: .note}
+
+## Configuring notification settings for an individual operation
+
+You can view default notification settings when you perform an indexing operation. You can also set up additional notifications. For example, if you want to configure an additional notification for a reindex operation, perform the following steps:
+
+1. From the top menu, select **OpenSearch Plugins** > **Index Management**.
+
+1. Under **Index Management**, select **Indices**.
+
+1. Select the index you want to reindex.
+
+1. Select **Reindex** from the **Actions** dropdown list.
+
+1. After selecting all reindex options, expand **Advanced settings**. Under **Notifications**, default notifications are listed. 
+    
+    If you don't have permission to view notification settings, you will not be able to view the default settings. 
+    {: .note}
+
+1. To receive additional notifications, select **Send additional notifications**, as shown in the following image.
+
+    ![Individual notification settings]({{site.url}}{{site.baseurl}}/images/admin-ui-index/notifications-individual.png)
+
+1. Select whether you want to be notified when the operation has failed or completed.
+
+1. Select a channel from the **Notification channels** dropdown list. If you want to configure a new notification channel, select **Manage channels**.
+    
+    To configure a new notification channel, ensure the `dashboards-notification` plugin is enabled in OpenSearch Dashboards. 
+    {: .note}
+    
+1. Select the **Reindex** button.