Fix

doc/code_snippets/snippets/migrations/README.md

@@ -1,4 +1,4 @@
-# Centralized configuration storages
+# Centralized migrations with tt
 
 Sample applications demonstrating how to use the centralized migration mechanism
 for Tarantool EE clusters via the tt utility. Learn more at [Centralized configuration storages](https://www.tarantool.io/en/doc/latest/platform/https://www.tarantool.io/en/doc/latest/platform/ddl_dml/migrations/).

doc/platform/ddl_dml/migrations/centralized_migrations_tt.rst

@@ -8,15 +8,18 @@ Centralized migrations with tt
 In this section, you learn to use the centralized migration management mechanism
 implemented in the Enterprise Edition of the :ref:`tt <tt-cli>` utility.
 
-See also:
-
--   :ref:`tt migrations reference <tt-migrations>` for the full list of command-line options.
--   :ref:`tcm_cluster_migrations` to learn about managing migrations from |tcm_full_name|.
+The section includes the following tutorials:
 
 .. toctree::
     :maxdepth: 1
 
     basic_migrations_tt
     upgrade_migrations_tt
     extend_migrations_tt
-    troubleshoot_migrations_tt
+    troubleshoot_migrations_tt
+
+
+See also:
+
+-   :ref:`tt migrations reference <tt-migrations>` for the full list of command-line options.
+-   :ref:`tcm_cluster_migrations` to learn about managing migrations from |tcm_full_name|.

doc/platform/ddl_dml/migrations/extend_migrations_tt.rst

@@ -1,7 +1,7 @@
 ..  _extend_migrations_tt:
 
-Centralized migrations with tt
-==============================
+Extending the cluster
+=====================
 
 **Example on GitHub:** `migrations <https://github.com/tarantool/doc/tree/latest/doc/code_snippets/snippets/migrations>`_
 
@@ -13,7 +13,9 @@ added cluster instances using the centralized migration management mechanism.
 Prerequisites
 -------------
 
-Before starting this tutorial, complete the :ref:`_basic_migrations_tt` and :ref:`upgrade_migrations_tt`
+Before starting this tutorial, complete the :ref:`basic_migrations_tt` and :ref:`upgrade_migrations_tt`.
+As a result, you have a sharded Tarantool EE cluster that uses an etcd-based configuration
+storage. The cluster has a space with two indexes.
 
 ..  _extend_migrations_tt_cluster:
 
@@ -71,34 +73,20 @@ Apply all stored migrations to the cluster to load the same data schema to the n
 
 .. code-block:: console
 
-    $ tt migrations apply http://app_user:config_pass@localhost:2379/myapp \
-                          --tarantool-username=client --tarantool-password=secret
-       • router-001:
-       •     000001_create_writes_space.lua: skipped, already applied
-       •     000002_create_writers_index.lua: skipped, already applied
-       •     000003_alter_writers_space.lua: skipped, already applied
-       • storage-001:
-       •     000001_create_writes_space.lua: skipped, already applied
-       •     000002_create_writers_index.lua: skipped, already applied
-       •     000003_alter_writers_space.lua: skipped, already applied
-       • storage-002:
-       •     000001_create_writes_space.lua: skipped, already applied
-       •     000002_create_writers_index.lua: skipped, already applied
-       •     000003_alter_writers_space.lua: skipped, already applied
-       • storage-003:
-       •     000001_create_writes_space.lua: successfully applied
-       •     000002_create_writers_index.lua: successfully applied
-       •     000003_alter_writers_space.lua: successfully applied
+     $ tt migrations apply http://app_user:config_pass@localhost:2379/myapp \
+                           --tarantool-username=client --tarantool-password=secret
+                           --replicaset storage-003
 
 .. note::
 
-    You can apply migrations to a specific replica set using the ``--replicaset`` option:
+    You can also apply migrations without specifying the replica set. All published
+    migrations are already applied on other replica sets, so ``tt`` skips the
+    operation on them.
 
     .. code-block:: console
 
-         $ tt migrations apply http://app_user:config_pass@localhost:2379/myapp \
-                               --tarantool-username=client --tarantool-password=secret
-                               --replicaset storage-003
+        $ tt migrations apply http://app_user:config_pass@localhost:2379/myapp \
+                              --tarantool-username=client --tarantool-password=secret
 
 To make sure that the space exists on the new instances, connect to ``storage-003-a``
 and check ``box.space.writers``:

doc/platform/ddl_dml/migrations/index.rst

@@ -165,6 +165,6 @@ troubleshooting migration issues. :ref:`troubleshooting_migrations_tt`.
 ..  toctree::
     :maxdepth: 1
 
-    space_upgrade
     centralized_migrations_tt
-    troubleshooting_migrations_tt
+    space_upgrade
+

doc/platform/ddl_dml/migrations/upgrade_migrations_tt.rst

@@ -6,7 +6,7 @@ Complex migrations with space.upgrade()
 **Example on GitHub:** `migrations <https://github.com/tarantool/doc/tree/latest/doc/code_snippets/snippets/migrations>`_
 
 In this tutorial, you learn to write migrations that include data migration using
-the ``space.upgrade`` function.
+the ``space.upgrade()`` function.
 
 See also:
 
@@ -18,15 +18,19 @@ See also:
 Prerequisites
 -------------
 
-Before starting this tutorial, complete the :ref:`_basic_migrations_tt`.
+Before starting this tutorial, complete the :ref:`basic_migrations_tt`.
+As a result, you have a sharded Tarantool EE cluster that uses an etcd-based configuration
+storage. The cluster has a space with two indexes.
 
 ..  _upgrade_migrations_tt_write:
 
 Writing a complex migration
 ---------------------------
 
-Complex migrations require data migration along with schema migration. Insert some
-tuples into the space before proceeding to the next steps:
+Complex migrations require data migration along with schema migration. Connect to
+the router instance and insert some tuples into the space before proceeding to the next steps.
+
+.. code-block:: $ tt connect myapp:router-001
 
 .. code-block:: tarantoolsession
 
@@ -98,26 +102,26 @@ Publish the new migration to etcd. Migrations that already exist in the storage
 
 .. code-block:: console
 
-    $ tt migrations publish http://app_user:config_pass@localhost:2379/myapp
-       • 000001_create_writes_space.lua: skipped, key "000001_create_writes_space.lua" already exists with the same content
-       • 000002_create_writers_index.lua: skipped, key "000002_create_writers_index.lua" already exists with the same content
-       • 000003_alter_writers_space.lua: successfully published to key "000003_alter_writers_space.lua"
+    $ tt migrations publish http://app_user:config_pass@localhost:2379/myapp \
+                            migrations/scenario/000003_alter_writers_space.lua
 
 .. note::
 
-    You can also publish a single migration file by passing a path to it as an argument:
+    You can also publish all migrations from the default location ``/migrations/scenario``.
+    All other migrations stored in this directory are already published, so ``tt``
+    skips them.
 
     .. code-block:: console
 
-        $ tt migrations publish http://app_user:config_pass@localhost:2379/myapp \
-                                migrations/scenario/000003_alter_writers_space.lua
+        $ tt migrations publish http://app_user:config_pass@localhost:2379/myapp
+
 
 ..  _upgrade_migrations_tt_apply:
 
 Applying the migration
 ----------------------
 
-Apply the migrations:
+Apply the published migrations:
 
 .. code-block:: console