Add documentation for Dashboards index operations (#2938)

* Add documentation for Dashboards index operations

Signed-off-by: ariamarble <armarble@amazon.com>

* Added page content

Signed-off-by: ariamarble <armarble@amazon.com>

* Made tech review changes

Signed-off-by: ariamarble <armarble@amazon.com>

* Made doc review changes

Signed-off-by: ariamarble <armarble@amazon.com>

* Apply suggestions from editorial review

Co-authored-by: Nathan Bower <nbower@amazon.com>
Co-authored-by: kolchfa-aws <105444904+kolchfa-aws@users.noreply.github.com>

* further editorial changes

Signed-off-by: ariamarble <armarble@amazon.com>

* couple more small changes

Signed-off-by: ariamarble <armarble@amazon.com>

---------

Signed-off-by: ariamarble <armarble@amazon.com>
Co-authored-by: Nathan Bower <nbower@amazon.com>
Co-authored-by: kolchfa-aws <105444904+kolchfa-aws@users.noreply.github.com>

_dashboards/admin-ui-index/datastream.md

@@ -0,0 +1,90 @@
+---
+layout: default
+title: Data stream management
+parent: Index and snapshot management in OpenSearch Dashboards
+nav_order: 20
+---
+
+# Data stream management
+Introduced 2.6
+{: .label .label-purple }
+
+In OpenSearch Dashboards, the **Index Management** application allows you to view and manage [data streams]({{site.url}}{{site.baseurl}}/opensearch/data-streams/) as shown in the following image.
+
+![Data Streams]({{site.url}}{{site.baseurl}}/images/admin-ui-index/datastreams1.png)
+
+## Viewing a data stream
+
+To view a data stream and its health status, choose **Data streams** under **Index management** as shown in the following image.
+
+![Data Streams]({{site.url}}{{site.baseurl}}/images/admin-ui-index/datastreams5.png)
+
+The following are the three data stream health statuses:
+
+- Green: All primary and replica shards are assigned.
+- Yellow: At least one replica shard is not assigned.
+- Red: At least one primary shard is not assigned.
+
+## Creating a data stream
+
+To create a data stream, perform the following steps:
+
+1. Under **Index Management**, choose **Data streams**.
+
+1. Choose **Create data stream**.
+
+1. Enter a name for the data stream under **Data stream name**.
+
+1. Ensure that you have a matching index template. This will be populated under **Matching index template**, as shown in the following image.
+
+    ![Data Streams]({{site.url}}{{site.baseurl}}/images/admin-ui-index/datastreams3.png)
+
+1. The **Template details** and **Index alias** sections are read-only. This will inform you of the backing indexes used in the data stream.
+
+1. Optionally, under **Advanced settings** you can specify the number of primary shards, number of replicas, and the refresh interval, as shown in the following image.
+
+    ![Data Streams]({{site.url}}{{site.baseurl}}/images/admin-ui-index/datastreams4.png)
+
+1. Choose **Create data stream**.
+
+## Deleting a data stream
+
+To delete a data stream, perform the following steps:
+
+1. Under **Index Management**, choose **Data streams**.
+
+1. Select the data stream you would like to delete.
+
+1. Choose **Actions**, and then choose **Delete**.
+
+## Rolling over a data stream
+
+To perform a rollover operation on a data stream, perform the following steps:
+
+1. Under **Index Management**, choose **Data streams**.
+
+1. Choose **Actions**, and then choose **Rollover**, as shown in the following image.
+
+    ![Rollover]({{site.url}}{{site.baseurl}}/images/admin-ui-index/rollover1.png)
+
+1. Under **Configure source**, select the source data stream on which you want to perform the rollover operation.
+
+1. Choose **Rollover**, as shown in the following image.
+
+    ![Rollover]({{site.url}}{{site.baseurl}}/images/admin-ui-index/rollover3.png)
+
+## Force merging data streams
+
+To perform a force merge operation on two or more indexes, perform the following steps:
+
+1. Under **Index Management**, choose **Data streams**.
+
+1. Select the data streams on which you want to perform the force merge operation.
+
+1. Choose **Actions**, and then choose **Force merge**.
+
+1. Under **Configure source index**, specify the data streams you want to force merge.
+
+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)

_dashboards/admin-ui-index/forcemerge.md

@@ -0,0 +1,46 @@
+---
+layout: default
+title: Force merge management
+parent: Index and snapshot management in OpenSearch Dashboards
+nav_order: 30
+---
+
+# Force merge management
+Introduced 2.6
+{: .label .label-purple }
+
+OpenSearch Dashboards allows you to perform a [force merge]({{site.url}}{{site.baseurl}}/im-plugin/ism/error-prevention/index/#force_merge/) operation on two or more indexes with **Index Management**.
+
+## Force merging indexes
+
+To perform a force merge operation on two or more indexes, perform the following steps:
+
+1. Under **Index Management**, choose **Indices**.
+
+1. Select the indexes you want to force merge.
+
+1. Choose **Actions**, and then choose **Force merge**, as shown in the following image.
+
+    ![Force Merge]({{site.url}}{{site.baseurl}}/images/admin-ui-index/forcemerge1.png)
+
+1. Under **Configure source index**, specify the indexes you want to force merge.
+
+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)
+
+## Force merging data streams
+
+To perform a force merge operation on two or more indexes, perform the following steps:
+
+1. Under **Index Management**, choose **Data streams**.
+
+1. Select the data streams you want to force merge.
+
+1. Choose **Actions**, and then choose **Force merge**.
+
+1. Under **Configure source index**, specify the data streams you want to force merge.
+
+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)

_dashboards/admin-ui-index/rollover.md

@@ -0,0 +1,52 @@
+---
+layout: default
+title: Rollover management
+parent: Index and snapshot management in OpenSearch Dashboards
+nav_order: 40
+---
+
+# Rollover management
+Introduced 2.6
+{: .label .label-purple }
+
+OpenSearch Dashboards allows you to perform an [index rollover]({{site.url}}{{site.baseurl}}/im-plugin/ism/error-prevention/index/#rollover) operation with **Index Management**.
+
+## Data streams
+
+To perform a rollover operation on a data stream, perform the following steps:
+
+1. Under **Index Management**, choose **Data streams**.
+
+1. Choose **Actions**, and then choose **Rollover**, as shown in the following image.
+
+    ![Rollover]({{site.url}}{{site.baseurl}}/images/admin-ui-index/rollover1.png)
+
+1. Under **Configure source**, select the source data stream on which you want to perform the rollover operation.
+
+1. Choose **Rollover**, as shown in the following image.
+
+    ![Rollover]({{site.url}}{{site.baseurl}}/images/admin-ui-index/rollover3.png)
+
+## Aliases
+
+To perform a rollover operation on an alias, perform the following steps:
+
+1. Under **Index Management**, choose **Aliases**.
+
+1. Choose **Actions**, and then choose **Rollover**, as shown in the following image.
+
+    ![Rollover]({{site.url}}{{site.baseurl}}/images/admin-ui-index/rollover2.png)
+
+1. Under **Configure source**, select the source alias on which you want to perform the rollover operation.
+
+1. If the alias does not contain a write index, you will be prompted to assign a write index, as shown in the following image. 
+
+    ![Rollover]({{site.url}}{{site.baseurl}}/images/admin-ui-index/rollover4.png)
+
+1. Under **Configure a new rollover index** and on the **Define index** pane, specify an index name and an optional index alias.
+
+1. Under **Index settings**, specify the number of primary shards, the number of replicas, and the refresh interval, as shown in the following image.
+
+    ![Rollover]({{site.url}}{{site.baseurl}}/images/admin-ui-index/rollover5.png)
+
+1. Choose **Rollover**.