DOCS-13029 Cherry Pick/Merge (#1130)

Author: kennethdyer

source/core/replica-set-arbiter.txt

@@ -56,6 +56,13 @@ Replica Set Protocol Version and Arbiter
 
 .. include:: /includes/extracts/arbiters-and-pvs-with-reference.rst
 
+For more information, see the :dbcommand:`setFeatureCompatibilityVersion` command.
+
+Feature Compatibility Version
+-----------------------------
+
+.. include:: /includes/arbiter-fcv.rst
+
 .. _rollbacks-multi-arbiters:
 
 Don't Deploy Multiple Arbiters

source/includes/arbiter-fcv-version.rst

@@ -0,0 +1,3 @@
+
+For example, an arbiter in a MongoDB |newversion| cluster, has an FCV
+value of |oldversion|.

source/includes/arbiter-fcv.rst

@@ -0,0 +1,5 @@
+
+Arbiters do not replicate the :data:`admin.system.version` collection.
+Because of this, arbiters always have a Feature Compatibility Version equal
+to the downgrade version of the binary, regardless of the FCV value of the
+replica set.

source/reference/command/setFeatureCompatibilityVersion.txt

@@ -170,6 +170,15 @@ This command must perform writes to an internal system collection. If
 for any reason the command does not complete successfully, you can
 safely retry the command as the operation is idempotent.
 
+
+Feature Compatibility in Arbiters
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+
+.. include:: /includes/arbiter-fcv.rst
+
+For example, an arbiter in a MongoDB 5.0 cluster, has an FCV
+value of 4.4.
+
 Examples
 --------
 

source/release-notes/4.2-downgrade-replica-set.txt

@@ -90,6 +90,13 @@ To downgrade the ``featureCompatibilityVersion`` of your replica set:
    If any member returns a ``featureCompatibilityVersion`` of ``"4.2"``,
    wait for the member to reflect version ``"4.0"`` before proceeding.
 
+.. note::
+
+   .. include:: /includes/arbiter-fcv.rst
+
+   .. include:: /includes/arbiter-fcv-version.rst
+
+
 For more information on the returned ``featureCompatibilityVersion``
 value, see :ref:`view-fcv`.
 

source/release-notes/4.2-downgrade-sharded-cluster.txt

@@ -86,6 +86,13 @@ cluster:
    If any member returns a ``featureCompatibilityVersion`` of ``"4.2"``,
    wait for the member to reflect version ``"4.0"`` before proceeding.
 
+.. note::
+
+   .. include:: /includes/arbiter-fcv.rst
+
+   .. include:: /includes/arbiter-fcv-version.rst
+
+
 For more information on the returned ``featureCompatibilityVersion``
 value, see :ref:`view-fcv`.
 

source/release-notes/4.4-downgrade-replica-set.txt

@@ -133,6 +133,13 @@ To downgrade the ``featureCompatibilityVersion`` of your replica set:
 For more information on the returned ``featureCompatibilityVersion``
 value, see :ref:`view-fcv`.
 
+.. note::
+
+   .. include:: /includes/arbiter-fcv.rst
+
+   .. include:: /includes/arbiter-fcv-version.rst
+
+
 3. Remove FCV |newversion| Persisted Features
 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
 

source/release-notes/4.4-downgrade-sharded-cluster.txt

@@ -141,6 +141,13 @@ cluster:
    If any member returns a ``featureCompatibilityVersion`` of |newfcv|,
    wait for the member to reflect version |oldfcv| before proceeding.
 
+.. note::
+
+  .. include:: /includes/arbiter-fcv.rst
+
+  .. include:: /includes/arbiter-fcv-version.rst
+
+
 For more information on the returned ``featureCompatibilityVersion``
 value, see :ref:`view-fcv`.
 

source/release-notes/5.0-downgrade-replica-set.txt

@@ -134,6 +134,12 @@ set:
    If any member returns a ``featureCompatibilityVersion`` of |newfcv|,
    wait for the member to reflect version |oldfcv| before proceeding.
 
+.. note::
+
+  .. include:: /includes/arbiter-fcv.rst
+
+  .. include:: /includes/arbiter-fcv-version.rst
+
 For more information on the returned ``featureCompatibilityVersion``
 value, see :ref:`view-fcv`.
 

source/release-notes/5.0-downgrade-sharded-cluster.txt

@@ -162,6 +162,12 @@ cluster:
    If any member returns a ``featureCompatibilityVersion`` of |newfcv|,
    wait for the member to reflect version |oldfcv| before proceeding.
 
+.. note::
+
+  .. include:: /includes/arbiter-fcv.rst
+
+  .. include:: /includes/arbiter-fcv-version.rst
+
 For more information on the returned ``featureCompatibilityVersion``
 value, see :ref:`view-fcv`.