Fix ambiguity with settings for search_backpressure (#6655)

* Fix ambiguity with settings for search_backpressure

This page is lacking in clearly stating how to enable/configure search_backpressure. While it may be domain knowledge that cluster settings always use `_cluster/settings`, many people that administrate or use OpenSearch are not full time OpenSearch admins and this info is very easy to document.

Signed-off-by: Drew Miranda <107503402+drewmiranda-gl@users.noreply.github.com>

* Update _tuning-your-cluster/availability-and-recovery/search-backpressure.md

Co-authored-by: kolchfa-aws <105444904+kolchfa-aws@users.noreply.github.com>
Signed-off-by: Drew Miranda <107503402+drewmiranda-gl@users.noreply.github.com>

* Update _tuning-your-cluster/availability-and-recovery/search-backpressure.md

Co-authored-by: kolchfa-aws <105444904+kolchfa-aws@users.noreply.github.com>
Signed-off-by: Drew Miranda <107503402+drewmiranda-gl@users.noreply.github.com>

* Update _tuning-your-cluster/availability-and-recovery/search-backpressure.md

Co-authored-by: kolchfa-aws <105444904+kolchfa-aws@users.noreply.github.com>
Signed-off-by: Drew Miranda <107503402+drewmiranda-gl@users.noreply.github.com>

* Update _tuning-your-cluster/availability-and-recovery/search-backpressure.md

Co-authored-by: kolchfa-aws <105444904+kolchfa-aws@users.noreply.github.com>
Signed-off-by: Drew Miranda <107503402+drewmiranda-gl@users.noreply.github.com>

* Update _tuning-your-cluster/availability-and-recovery/search-backpressure.md

Co-authored-by: kolchfa-aws <105444904+kolchfa-aws@users.noreply.github.com>
Signed-off-by: Drew Miranda <107503402+drewmiranda-gl@users.noreply.github.com>

* Update _tuning-your-cluster/availability-and-recovery/search-backpressure.md

Co-authored-by: kolchfa-aws <105444904+kolchfa-aws@users.noreply.github.com>
Signed-off-by: Drew Miranda <107503402+drewmiranda-gl@users.noreply.github.com>

* Update _tuning-your-cluster/availability-and-recovery/search-backpressure.md

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

* Update search-backpressure.md

fix formatting

Signed-off-by: Drew Miranda <107503402+drewmiranda-gl@users.noreply.github.com>

---------

Signed-off-by: Drew Miranda <107503402+drewmiranda-gl@users.noreply.github.com>
Signed-off-by: kolchfa-aws <105444904+kolchfa-aws@users.noreply.github.com>
Co-authored-by: kolchfa-aws <105444904+kolchfa-aws@users.noreply.github.com>

_tuning-your-cluster/availability-and-recovery/search-backpressure.md

@@ -10,7 +10,7 @@ redirect_from:
 
 # Search backpressure
 
-Search backpressure is a mechanism used to identify resource-intensive search requests and cancel them when the node is under duress. If a search request on a node or shard has breached the resource limits and does not recover within a certain threshold, it is rejected. These thresholds are dynamic and configurable through [cluster settings](#search-backpressure-settings). 
+Search backpressure is a mechanism used to identify resource-intensive search requests and cancel them when the node is under duress. If a search request on a node or shard has breached the resource limits and does not recover within a certain threshold, it is rejected. These thresholds are dynamic and configurable through [cluster settings](#search-backpressure-settings) using the `/_cluster/settings` API endpoint. 
 
 ## Measuring resource consumption
 
@@ -78,6 +78,20 @@ Search backpressure runs in `monitor_only` (default), `enforced`, or `disabled`
 
 Search backpressure adds several settings to the standard OpenSearch cluster settings. These settings are dynamic, so you can change the default behavior of this feature without restarting your cluster.
 
+To configure these settings, send a PUT request to `/_cluster/settings`:
+
+```json
+PUT /_cluster/settings
+{
+  "persistent": {
+    "search_backpressure": {
+      "mode": "monitor_only"
+    }
+  }
+}
+```
+{% include copy-curl.html %}
+
 Setting | Default | Description
 :--- | :--- | :---
 search_backpressure.mode | `monitor_only` | The search backpressure [mode](#search-backpressure-modes). Valid values are `monitor_only`, `enforced`, or `disabled`.
@@ -259,4 +273,4 @@ The `cancellation_stats` object contains the following statistics for the tasks
 Field Name | Data type | Description
 :--- | :--- | :---
 cancellation_count | Integer | The total number of tasks marked for cancellation since the node last restarted.
-cancellation_limit_reached_count | Integer | The number of times when the number of tasks eligible for cancellation exceeded the set cancellation threshold.
+cancellation_limit_reached_count | Integer | The number of times when the number of tasks eligible for cancellation exceeded the set cancellation threshold.