Add upgrade guide 4.x to 4.y

Fixes #2010

(cherry picked from commit 3afe549)

docs/source/upgrade/index.rst

@@ -7,6 +7,7 @@ Upgrade Scylla Monitoring Stack
    :titlesonly:
    :hidden:
 
+   Monitoring 4.x to 4.y <upgrade-guide-from-monitoring-4.x-to-monitoring-4.y>
    Monitoring 3.x to 4.y <upgrade-guide-from-monitoring-3.x-to-monitoring-4.y>
    Monitoring 3.x to 3.y <upgrade-guide-from-monitoring-3.x-to-monitoring-3.y>
    Monitoring 2.x to 3.y <upgrade-guide-from-monitoring-2.x-to-monitoring-3.y>
@@ -25,6 +26,8 @@ Upgrade Scylla Monitoring Stack
 
 Procedures for upgrading the Scylla Monitoring Stack.
 
+* :doc:`Upgrade Guide - Monitoring 4.x to 4.y <upgrade-guide-from-monitoring-4.x-to-monitoring-4.y>`
+
 * :doc:`Upgrade Guide - Monitoring 3.x to 4.y <upgrade-guide-from-monitoring-3.x-to-monitoring-4.y>`
 
 * :doc:`Upgrade Guide - Monitoring 3.x to 3.y <upgrade-guide-from-monitoring-3.x-to-monitoring-3.y>`

docs/source/upgrade/upgrade-guide-from-monitoring-4.x-to-monitoring-4.y.rst

@@ -0,0 +1,138 @@
+==================================================================
+Upgrade Guide - ScyllaDB Monitoring 4.x to ScyllaDB Monitoring 4.y
+==================================================================
+
+This document is a step by step procedure for upgrading ScyllaDB Monitoring Stack from version 4.x to 4.y, for example, between 4.0 to 4.0.1.
+
+Upgrade Procedure
+=================
+
+We recommend installing the new release next to the old one, running both in parallel, and making sure it is working as expected before uninstalling the old version.
+
+Change to the directory you want to install the new Monitoring stack.
+Download the latest release:
+You can download the .zip or the .tar.
+
+Install 4.y (The new version)
+-----------------------------
+
+.. code-block:: bash
+
+                wget -L https://github.com/scylladb/scylla-monitoring/archive/scylla-monitoring-4.y.zip
+                unzip scylla-monitoring-4.y.zip
+                cd scylla-monitoring-scylla-monitoring-4.y/
+
+Replace “y” with the new minor release number, for example, 4.0.1.zip
+
+Setting the server's files
+--------------------------
+
+Copy the ``scylla_servers.yml`` and ``scylla_manager_servers.yml`` from the version that is already installed.
+
+.. code-block:: bash
+
+                cp /path/to/monitoring/4.x/prometheus/scylla_servers.yml prometheus/
+                cp /path/to/monitoring/4.x/prometheus/scylla_manager_servers.yml.yml prometheus/
+
+Validate the new version is running the correct version
+-------------------------------------------------------
+
+Run:
+
+.. code-block:: bash
+
+                ./start-all.sh --version
+
+To validate the Scylla-Monitoring version.
+
+
+Validate the version installed correctly
+----------------------------------------
+
+To validate that the Monitoring stack starts correctly, first in parallel to the current (4.x) stack.
+
+.. code-block:: bash
+
+                ./start-all.sh -p 9091 -g 3001 -m 9095
+
+Browse to ``http://{ip}:9091``
+And check the Grafana dashboard
+
+Note that we are using different port numbers for Grafana, Prometheus, and the Alertmanager.
+
+.. caution::
+
+   Important: do not use the local dir flag when testing!
+
+When you are satisfied with the data in the dashboard, you can shut down the containers.
+
+.. caution::
+
+   Important: Do not kill the 4.x version that is currently running.
+
+Killing the new 4.y Monitoring stack in testing mode
+----------------------------------------------------
+
+Use the following command to kill the containers:
+
+.. code-block:: bash
+
+                ./kill-all.sh -p 9091 -g 3001 -m 9095
+
+You can start and stop the new 4.y version while testing.
+
+Move to version 4.y (the new version)
+-------------------------------------
+
+Note: migrating will cause a few seconds of blackout in the system.
+
+We assume that you are using external volume to store the metrics data.
+
+Kill all containers
+^^^^^^^^^^^^^^^^^^^
+
+At this point you have two monitoring stacks running side by side, you should kill both before
+continuing.
+
+Kill the newer version that runs in testing mode by following the instructions on how to `Killing the new 4.y Monitoring stack in testing mode`_
+in the previous section
+
+kill the older 4.x version containers by running:
+
+.. code-block:: bash
+
+                ./kill-all.sh
+
+Start version 4.y in normal mode
+
+
+From the new root of the `scylla-monitoring-scylla-monitoring-4.y` run
+
+.. code-block:: bash
+
+                ./start-all.sh -d /path/to/data/dir
+
+
+Point your browser to ``http://{ip}:3000`` and see that the data is there.
+
+Rollback to version 4.x
+-----------------------
+
+
+To rollback during the testing mode, follow `Killing the new 4.y Monitoring stack in testing mode`_ as explained previously
+and the system will continue to operate normally.
+
+To rollback to version 4.x after you completed the moving to version 4.y (as shown above).
+Run:
+
+.. code-block:: bash
+
+                ./kill-all.sh
+                cd /path/to/scylla-grafana-4.x/
+                ./start-all.sh -d /path/to/data/dir
+
+Related Links
+=============
+
+* `ScyllaDB Monitoring </operating-scylla/monitoring/>`_
+* :doc:`Upgrade</upgrade/index>`