Add troubleshooting doc for missing tier (#87526)

Co-authored-by: Lee Hinman <dakrone@users.noreply.github.com>

docs/reference/tab-widgets/troubleshooting/data/add-tier-widget.asciidoc

@@ -0,0 +1,40 @@
+++++
+<div class="tabs" data-tab-group="host">
+  <div role="tablist" aria-label="Enable tier">
+    <button role="tab"
+            aria-selected="true"
+            aria-controls="cloud-tab-enable-tier"
+            id="cloud-enable-tier">
+      Elasticsearch Service
+    </button>
+    <button role="tab"
+            aria-selected="false"
+            aria-controls="self-managed-tab-enable-tier"
+            id="self-managed-enable-tier"
+            tabindex="-1">
+      Self-managed
+    </button>
+  </div>
+  <div tabindex="0"
+       role="tabpanel"
+       id="cloud-tab-enable-tier"
+       aria-labelledby="cloud-enable-tier">
+++++
+
+include::add-tier.asciidoc[tag=cloud]
+
+++++
+  </div>
+  <div tabindex="0"
+       role="tabpanel"
+       id="self-managed-tab-enable-tier"
+       aria-labelledby="self-managed-enable-tier"
+       hidden="">
+++++
+
+include::add-tier.asciidoc[tag=self-managed]
+
+++++
+  </div>
+</div>
+++++

docs/reference/tab-widgets/troubleshooting/data/add-tier.asciidoc

@@ -0,0 +1,127 @@
+//////////////////////////
+
+[source,console]
+--------------------------------------------------
+PUT my-index-000001
+
+--------------------------------------------------
+// TESTSETUP
+
+[source,console]
+--------------------------------------------------
+DELETE my-index-000001
+--------------------------------------------------
+// TEARDOWN
+
+//////////////////////////
+
+
+// tag::cloud[]
+In order to get the shards assigned we need enable a new tier in the deployment.
+
+**Use {kib}**
+
+//tag::kibana-api-ex[]
+. Log in to the {ess-console}[{ecloud} console].
++
+
+. On the **Elasticsearch Service** panel, click the name of your deployment. 
++
+
+NOTE:
+If the name of your deployment is disabled your {kib} instances might be
+unhealthy, in which case please contact https://support.elastic.co[Elastic Support].
+If your deployment doesn't include {kib}, all you need to do is 
+{cloud}/ec-access-kibana.html[enable it first].
+
+. Open your deployment's side navigation menu (placed under the Elastic logo in the upper left corner)
+and go to **Dev Tools > Console**.
++
+[role="screenshot"]
+image::images/kibana-console.png[{kib} Console,align="center"]
+
+. Determine which tier an index expects for assignment. <<indices-get-settings, Retrieve>>
+the configured value for the `index.routing.allocation.include._tier_preference`
+setting:
++
+[source,console]
+----
+GET /my-index-000001/_settings/index.routing.allocation.include._tier_preference?flat_settings
+----
++
+The reponse will look like this:
++
+[source,console-result]
+----
+{
+  "my-index-000001": {
+    "settings": {
+      "index.routing.allocation.include._tier_preference": "data_warm,data_hot" <1>
+    }
+  }
+}
+----
+// TESTRESPONSE[skip:the result is for illustrating purposes only]
++
+<1> Represents a comma-separated list of data tier node roles this index is allowed
+to be allocated on, the first one in the list being the one with the higher priority
+i.e. the tier the index is targeting.
+e.g. in this example the tier preference is `data_warm,data_hot` so the index is
+targeting the `warm` tier and more nodes with the `data_warm` role are needed in
+the {es} cluster.
+
+. Open your deployment's side navigation menu (placed under the Elastic logo in the upper left corner)
+and go to **Manage this deployment**.
+
+. From the right hand side, click to expand the **Manage** dropdown button and
+select **Edit deployment** from the list of options.
+
+. On the **Edit** page, click on **+ Add Capacity** for the tier you identified
+you need to enable in your deployment. Choose the desired size and availability
+zones for the new tier.
+
+. Navigate to the bottom of the page and click the **Save** button.
+
+//end::kibana-api-ex[]
+// end::cloud[]
+
+// tag::self-managed[]
+In order to get the shards assigned you can add more nodes to your {es} cluster 
+and assign the index's target tier <<assign-data-tier, node role>> to the new 
+nodes. 
+
+To determine which tier an index requires for assignment, use the <<indices-get-settings, get index setting>>
+API to retrieve the configured value for the `index.routing.allocation.include._tier_preference`
+setting:
+
+[source,console]
+----
+GET /my-index-000001/_settings/index.routing.allocation.include._tier_preference?flat_settings
+----
+// TEST[continued]
+
+
+The reponse will look like this:
+
+[source,console-result]
+----
+{
+  "my-index-000001": {
+    "settings": {
+      "index.routing.allocation.include._tier_preference": "data_warm,data_hot" <1>
+    }
+  }
+}
+----
+// TESTRESPONSE[skip:the result is for illustrating purposes only]
+
+
+<1> Represents a comma-separated list of data tier node roles this index is allowed
+to be allocated on, the first one in the list being the one with the higher priority
+i.e. the tier the index is targeting.
+e.g. in this example the tier preference is `data_warm,data_hot` so the index is
+targeting the `warm` tier and more nodes with the `data_warm` role are needed in
+the {es} cluster.
+
+// end::self-managed[]
+

docs/reference/troubleshooting.asciidoc

@@ -46,6 +46,8 @@ include::troubleshooting/data/enable-cluster-allocation.asciidoc[]
 
 include::troubleshooting/data/data-tiers-mixed-with-node-attr.asciidoc[]
 
+include::troubleshooting/data/add-tier.asciidoc[]
+
 include::troubleshooting/data/diagnose-unassigned-shards.asciidoc[]
 
 include::troubleshooting/data/increase-tier-capacity.asciidoc[]

docs/reference/troubleshooting/data/add-tier.asciidoc

@@ -0,0 +1,12 @@
+[[add-tier]]
+== Add a missing tier to the system
+
+The allocation of indices in an {es} deployment can be allocated on <<data-tiers, data tiers>>.
+
+In order to allow indices to be allocated, follow these steps to add the <<data-tiers, data tier>>
+the indices expect to be allocated on to your deployment:
+
+include::{es-repo-dir}/tab-widgets/troubleshooting/data/add-tier-widget.asciidoc[]
+
+
+