Adds warnings on replication related issues

doc/reference/reference_lua/box_space.rst

@@ -11,6 +11,62 @@ It has the data-manipulation functions ``select``, ``insert``, ``replace``,
 ``update``, ``upsert``, ``delete``, ``get``, ``put``. It also has members,
 such as id, and whether or not a space is enabled.
 
+..  WARNING::
+
+    Option 1 global Warning:
+    The following operations involve full space traversal:
+
+    - :doc:`./box_space/create_index`;
+    - :doc:`./box_space/alter`;
+    - :doc:`./box_space/format`.
+
+    Full traversal is the process of processing every node or element in the space structure exactly once
+    in a systematic manner. Full traversal may leadThese operations introduce replication lag for both 
+    synchronous and asynchronous replication and make writes with synchronous replication unavailable
+    for the whole duration of operation when initiated at the following conditions:
+
+    - initiated on a space with over 10000 tuples AND
+    - when the node is under any load (when it processes user requests/performs business operations).
+
+    To avoid issues:
+
+    - initiate named operations on spaces that do not exceed 10000 tuples OR 
+    - initiate named operations when the node is not under any load;
+    - instead of the ``space_object:format()`` operation, perform the :ref:`box_space-upgrade` operation.
+
+    Safe exceptions for named operations are:
+
+    - changing indexed field type to a more generic one («unsigned» to «number», «decimal» to «scalar»); 
+    - turning a unique index into a non-unique one; 
+    - changing some of the index parameters which do not require a rebuild (changing page_size of a vinyl space index).
+    - changing space format to a more generic one.
+
+    Option 2 global Warning:
+    The following operations involve full space traversal and introduce replication lag for both synchronous 
+    and asynchronous replication and make writes with synchronous replication unavailable for the whole duration 
+    of operation when initiated at certain conditions:
+
+    - :doc:`./box_space/create_index`;
+    - :doc:`./box_space/alter`;
+    - :doc:`./box_space/format`.
+
+    The issues occur when the operations are initiated at the following conditions:
+
+    - initiated on a space with over 10000 tuples AND
+    - when the node is under any load (when it processes user requests/performs business operations).
+
+    To avoid issues:
+
+    - initiate named operations on spaces that do not exceed 10000 tuples OR 
+    - initiate named operations when the node is not under any load;
+    - instead of the ``space_object:format()`` operation, perform the :ref:`box_space-upgrade` operation.
+
+    Safe exceptions for named operations are:
+    - changing indexed field type to a more generic one («unsigned» to «number», «decimal» to «scalar»); 
+    - turning a unique index into a non-unique one; 
+    - changing some of the index parameters which do not require a rebuild (changing page_size of a vinyl space index).
+    - changing space format to a more generic one.
+
 Below is a list of all ``box.space`` functions and members.
 
 ..  container:: table

doc/reference/reference_lua/box_space/alter.rst

@@ -11,6 +11,58 @@ space_object:alter()
         Since version :doc:`2.5.2 </release/2.5.2>`.
         Alter an existing space. This method changes certain space parameters.
 
+        ..  WARNING::
+
+            Option 1 alter Warning:
+
+            The ``space_object:alter()`` operation involves full space traversal. Full traversal
+            is the process of processing every node or element in the space structure exactly once
+            in a systematic manner.
+
+            Full traversal may lead to replication lag for both synchronous and asynchronous replication
+            and make writes with synchronous replication unavailable for the whole duration of operation
+            when initiated at the following conditions:
+
+            - initiated on a space with over 10000 tuples AND
+            - when the node is under any load (when it processes user requests/performs business operations).
+
+            To avoid issues:
+
+            - initiate the ``space_object:alter()`` operation on spaces that do not exceed 10000 tuples OR 
+            - initiate the ``space_object:alter()`` operation when the node is not under any load.
+
+            Safe exceptions for the ``space_object:alter()`` operation are:
+
+            - changing indexed field type to a more generic one («unsigned» to «number», «decimal» to «scalar»); 
+            - turning a unique index into a non-unique one; 
+            - changing some of the index parameters which do not require a rebuild (changing page_size of a vinyl space index).
+
+            In future releases, the ``space_object:alter()`` operation will be deprecated.
+
+            Option 2 alter Warning:
+
+            The ``space_object:alter()`` operation involve full space traversal and introduce replication lag for both
+            synchronous and asynchronous replication and make writes with synchronous replication unavailable for the
+            whole duration of operation when initiated at certain conditions.
+
+            The issues occur when the ``space_object:alter()`` operation is initiated at the following conditions:
+
+            - initiated on a space with over 10000 tuples AND
+            - when the node is under any load (when it processes user requests/performs business operations).
+
+            To avoid issues:
+
+            - initiate the ``space_object:alter()`` operation on spaces that do not exceed 10000 tuples OR 
+            - initiate the ``space_object:alter()`` operation when the node is not under any load.
+
+            Safe exceptions for the ``space_object:alter()`` operation are:
+
+            - changing indexed field type to a more generic one («unsigned» to «number», «decimal» to «scalar»); 
+            - turning a unique index into a non-unique one; 
+            - changing some of the index parameters which do not require a rebuild (changing page_size of a vinyl space index).
+
+            In future releases, the ``space_object:alter()`` operation will be deprecated.
+
         :param table options: the space options such as ``field_count``, ``user``,
                               ``format``, ``name``, and other. The full list of
                               these options with descriptions parameters is provided in

doc/reference/reference_lua/box_space/create_index.rst

@@ -13,6 +13,43 @@ space_object:create_index()
         tuples into it or select tuples from it. The first created index
         will be used as the primary-key index, so it must be unique.
 
+        ..  WARNING::
+
+            Option 1 create Warning:
+
+            The ``space_object:create_index()`` operation involves full space traversal. Full traversal
+            is the process of processing every node or element in the space structure exactly once
+            in a systematic manner.
+
+            Full traversal may lead to replication lag for both synchronous and asynchronous replication
+            and make writes with synchronous replication unavailable for the whole duration of operation
+            when initiated at the following conditions:
+
+            - initiated on a space with over 10000 tuples AND
+            - when the node is under any load (when it processes user requests/performs business operations).
+
+            To avoid issues:
+
+            - initiate the ``space_object:create_index()`` operation on spaces that do not exceed 10000 tuples OR 
+            - initiate the ``space_object:create_index()`` operation when the node is not under any load.
+
+            Option 2 create Warning:
+
+            The ``space_object:create_index()`` operation involve full space traversal and introduce replication lag for both
+            synchronous and asynchronous replication and make writes with synchronous replication unavailable for the
+            whole duration of operation when initiated at certain conditions.
+
+            The issues occur when the ``space_object:create_index()`` operation is initiated at the following conditions:
+
+            - initiated on a space with over 10000 tuples AND
+            - when the node is under any load (when it processes user requests/performs business operations).
+
+            To avoid issues:
+
+            - initiate the ``space_object:create_index()`` operation on spaces that do not exceed 10000 tuples OR 
+            - initiate the ``space_object:create_index()`` operation when the node is not under any load.
+
+
         :param space_object space_object: an :ref:`object reference
                                           <app_server-object_reference>`
         :param string index_name: name of index, which should conform to the

doc/reference/reference_lua/box_space/format.rst

@@ -10,6 +10,52 @@ space_object:format()
 
         Declare field names and :ref:`types <index-box_data-types>`.
 
+        ..  WARNING::
+
+            Option 1 format Warning:
+
+            The ``space_object:format()`` operation involves full space traversal. Full traversal
+            is the process of processing every node or element in the space structure exactly once
+            in a systematic manner.
+
+            Full traversal may lead to replication lag for both synchronous and asynchronous replication
+            and make writes with synchronous replication unavailable for the whole duration of operation
+            when initiated at the following conditions:
+
+            - initiated on a space with over 10000 tuples AND
+            - when the node is under any load (when it processes user requests/performs business operations).
+
+            To avoid issues:
+
+            - initiate the ``space_object:format()`` operation on spaces that do not exceed 10000 tuples OR 
+            - initiate the ``space_object:format()`` operation when the node is not under any load;
+            - instead of the ``space_object:format()`` operation, perform the :ref:`box_space-upgrade` operation.
+
+            Safe exception for the ``space_object:format()`` operation is:
+
+            - changing space format to a more generic one.
+
+            Option 2 format Warning:
+
+            The ``space_object:format()`` operation involve full space traversal and introduce replication lag for both
+            synchronous and asynchronous replication and make writes with synchronous replication unavailable for the
+            whole duration of operation when initiated at certain conditions.
+
+            The issues occur when the ``space_object:format()`` operation is initiated at the following conditions:
+
+            - initiated on a space with over 10000 tuples AND
+            - when the node is under any load (when it processes user requests/performs business operations).
+
+            To avoid issues:
+
+            - initiate the ``space_object:format()`` operation on spaces that do not exceed 10000 tuples OR 
+            - initiate the ``space_object:format()`` operation when the node is not under any load;
+            - instead of the ``space_object:format()`` operation, perform the :ref:`box_space-upgrade` operation.
+
+            Safe exception for the ``space_object:format()`` operation is:
+
+            - changing space format to a more generic one.
+
         :param space_object space_object: an :ref:`object reference
                                           <app_server-object_reference>`
         :param table format-clause: a list of field names and types