DOCS-15212 write blocking and fcv (#969)

* DOCS-15212-write-blocking-and-FCV

* DOCS-15212-write-blocking-and-FCV

* DOCS-15212-write-blocking-and-FCV

* DOCS-15212-write-blocking-and-FCV

* DOCS-15212-write-blocking-and-FCV

* DOCS-15212-write-blocking-and-FCV

* DOCS-15212-write-blocking-and-FCV

Co-authored-by: jason-price-mongodb <[email protected]>

Author: jason-price-mongodb

source/reference/command/setFeatureCompatibilityVersion.txt

@@ -170,6 +170,28 @@ 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.
 
+.. _setFeatureCompatibilityVersion-user-write-blocking:
+
+Cluster-to-Cluster Replication and User Write Blocking
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+
+Starting in MongoDB 6.0, if you need to downgrade the feature
+compatibility version, ensure cluster-to-cluster replication and user
+write blocking are disabled:
+
+#. If you enabled cluster-to-cluster replication, disable it.
+
+#. If you enabled user write blocking, disable it:
+
+   .. code-block:: javascript
+
+      db.runCommand( { setUserWriteBlockMode: 1, global: false } )
+
+#. Wait for the previous command to complete.
+
+#. Downgrade the feature compatibility version using
+   :dbcommand:`setFeatureCompatibilityVersion`.
+
 Examples
 --------
 

source/release-notes/6.0-compatibility.txt

@@ -61,6 +61,13 @@ single document.
 
 See :parameter:`indexMaxNumGeneratedKeysPerDocument`.
 
+Feature Compatibility Version and User Write Blocking
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+
+If you need to downgrade the feature compatibility version, ensure you
+disable cluster-to-cluster replication and user write blocking. See
+:ref:`setFeatureCompatibilityVersion-user-write-blocking`.
+
 Platform Support
 ----------------