DOCSP-44528-cutover-failure-warnings (#485) (#502)

* DOCSP-44528-cutover-failure-warnings'

* DOCSP-44528-cutover-failure-warnings'

* DOCSP-44528 adding disaster warning

* DOCSP-44528 adding disaster warning

* DOCSP-44528 copy edit

* DOCSP-44528 Maria comments

(cherry picked from commit 6d0064c)

Author: ltran-mdb2

source/includes/cluster-shutdown-warning.rst

@@ -0,0 +1,3 @@
+If the source cluster shuts down before ``mongosync`` can commit, such as in 
+a disaster scenario, the destination cluster might not have a consistent 
+snapshot of the source data. To learn more, see :ref:`c2c-behavior-consistency`.

source/reference/cutover-process.txt

@@ -16,16 +16,32 @@ You can finalize a migration and transfer your application
 workload from the source to the destination cluster using the
 :ref:`mongosync <c2c-mongosync>` cutover process.
 
-``mongosync`` should remain active until it reaches the
-:ref:`COMMITTED <c2c-state-committed>` state. This allows ``mongosync`` to sync
-any additional writes that occur during the migration.
-
 .. note::
 
    Before you switch your application workload to the
    destination cluster, you should always verify a successful sync.
    For more information, see :ref:`c2c-verification`.
 
+``mongosync`` should remain active until it reaches the
+:ref:`COMMITTED <c2c-state-committed>` state. This allows ``mongosync`` to sync
+any additional writes that occur during the migration.
+
+.. warning::
+
+   If you do not properly cutover from your source to your
+   destination, you may face the following issues:
+
+   - Inaccurate data on the destination cluster
+   - Unrecoverable and undiagnosable ``mongosync`` errors
+   - Reduced application availability, especially if there is
+     application-side enforcement of document schema or other
+     characteristics
+   - Incomplete transactions on the destination cluster
+   - Other unexpected cluster behavior
+
+   Use the following steps to safely finalize your cutover process and achieve
+   expected ``mongosync`` behavior. 
+
 Steps
 -----
 
@@ -103,11 +119,13 @@ Steps
          :language: json
          :copyable: false
 
-      .. note::
+      After you submit a ``commit`` request, call the ``progress`` endpoint
+      to ensure that the ``mongosync`` state is ``COMMITTING`` or
+      ``COMMITTED``.
+
+      .. warning::
 
-         After you submit a ``commit`` request, call the ``progress`` endpoint
-         to ensure that the ``mongosync`` state is ``COMMITTING`` or
-         ``COMMITTED``.
+         .. include:: /includes/cluster-shutdown-warning
 
    .. step:: Wait until you can perform writes on the destination cluster.
 

source/reference/mongosync/mongosync-behavior.txt

@@ -174,9 +174,7 @@ For any continuous synchronization use cases with ``mongosync``, ensure that
 ``mongosync`` commits before cutting over from the source to the 
 destination.
 
-If the source cluster shuts down before ``mongosync`` can commit, such as in 
-a disaster scenario, the destination cluster might not have a consistent 
-snapshot of the source data. To learn more, see :ref:`c2c-behavior-consistency`.
+.. include:: /includes/cluster-shutdown-warning
 
 .. note::