.. |SCYLLA_NAME| replace:: ScyllaDB

.. |SRC_VERSION| replace:: 6.0
.. |NEW_VERSION| replace:: 2024.2

.. |DEBIAN_SRC_REPO| replace:: Debian
.. _DEBIAN_SRC_REPO: https://www.scylladb.com/download/?platform=debian-11&version=scylla-6.0

.. |UBUNTU_SRC_REPO| replace:: Ubuntu
.. _UBUNTU_SRC_REPO: https://www.scylladb.com/download/?platform=ubuntu-22.04&version=scylla-6.0

.. |SCYLLA_DEB_SRC_REPO| replace:: ScyllaDB deb repo (|DEBIAN_SRC_REPO|_, |UBUNTU_SRC_REPO|_)

.. |SCYLLA_RPM_SRC_REPO| replace:: ScyllaDB rpm repo
.. _SCYLLA_RPM_SRC_REPO: https://www.scylladb.com/download/?platform=centos&version=scylla-6.0

.. |DEBIAN_NEW_REPO| replace:: Debian
.. _DEBIAN_NEW_REPO: https://www.scylladb.com/customer-portal/?product=ent&platform=debian-11&version=stable-release-2024.2

.. |UBUNTU_NEW_REPO| replace:: Ubuntu
.. _UBUNTU_NEW_REPO: https://www.scylladb.com/customer-portal/?product=ent&platform=ubuntu-22.04&version=stable-release-2024.2

.. |SCYLLA_DEB_NEW_REPO| replace:: ScyllaDB deb repo (|DEBIAN_NEW_REPO|_, |UBUNTU_NEW_REPO|_)

.. |SCYLLA_RPM_NEW_REPO| replace:: ScyllaDB rpm repo
.. _SCYLLA_RPM_NEW_REPO: https://www.scylladb.com/customer-portal/?product=ent&platform=centos7&version=stable-release-2024.2

.. |ROLLBACK| replace:: rollback
.. _ROLLBACK: ./#rollback-procedure

.. |SCYLLA_METRICS| replace:: ScyllaDB Enterprise Metrics Update - ScyllaDB Enterprise 6.0 to 2024.2
.. _SCYLLA_METRICS: ../metric-update-6.0-to-2024.2

=============================================================================
Upgrade Guide - |SCYLLA_NAME| |SRC_VERSION| to |NEW_VERSION|
=============================================================================

This document is a step-by-step procedure for upgrading from |SCYLLA_NAME| |SRC_VERSION| 
to |SCYLLA_NAME| Enterpise |NEW_VERSION|, and rollback to version |SRC_VERSION| if required.

This guide covers upgrading ScyllaDB on Red Hat Enterprise Linux (RHEL) CentOS, Debian, 
and Ubuntu. See :doc:`OS Support by Platform and Version </getting-started/os-support>` 
for information about supported versions.

This guide also applies when you're upgrading ScyllaDB Enterprise official image on EC2, 
GCP, or Azure.


Before You Upgrade ScyllaDB
================================

**Upgrade Your Driver**

If you're using a :doc:`ScyllaDB driver </using-scylla/drivers/cql-drivers/index>`, 
upgrade the driver before you upgrade ScyllaDB. The latest two versions of each driver 
are supported.

**Upgrade ScyllaDB Monitoring Stack**

If you're using the ScyllaDB Monitoring Stack, verify that your Monitoring Stack 
version supports the ScyllaDB version to which you want to upgrade. See 
`ScyllaDB Monitoring Stack Support Matrix <https://monitoring.docs.scylladb.com/stable/reference/matrix.html>`_.
  
We recommend upgrading the Monitoring Stack to the latest version.

**Check Feature Updates**

See the ScyllaDB Release Notes for the latest updates. The Release Notes are published 
at the `ScyllaDB Community Forum <https://forum.scylladb.com/>`_.

.. note::

   Unlike ScyllaDB 6.0, ScyllaDB Enterprise 2024.2 has **tablets disabled by
   default**. This means that after you upgrade to 2024.2:

   * Keyspaces that had tablets enabled in 6.0 will continue to work with tablets.
   * Keyspaces created with default settings after upgrading to 2024.2 will have
     tablets disabled.

     To use tablets, create a new keyspace with the ``tablets = { 'enabled': true }``
     option. For example:

       .. code::
  
           CREATE KEYSPACE my_keyspace
           WITH replication = {
               'class': 'NetworkTopologyStrategy',
               'replication_factor': 3
           } AND tablets = {
               'enabled': true
           };
     
       All tables created in this keyspace will use tablets. 
       Note that ``NetworkTopologyStrategy`` is required when tablets are enabled.

   See :doc:`Data Distribution with Tablets </architecture/tablets/>` for more information
   about tablets.

Upgrade Procedure
=================

A ScyllaDB upgrade is a rolling procedure that does **not** require full cluster shutdown.
For each of the nodes in the cluster, you will:

* Check that the cluster's schema is synchronized
* Drain the node and backup the data
* Backup the configuration file
* Stop ScyllaDB
* Download and install new ScyllaDB packages
* Start ScyllaDB
* Validate that the upgrade was successful


.. caution:: 

   Apply the procedure **serially** on each node. Do not move to the next node before 
   validating that the node you upgraded is up and running the new version.

**During** the rolling upgrade, it is highly recommended:

* Not to use the new |NEW_VERSION| features.
* Not to run administration functions, like repairs, refresh, rebuild, or add or remove 
  nodes. See `sctool <https://manager.docs.scylladb.com/stable/sctool/>`_ for suspending 
  ScyllaDB Manager's scheduled or running repairs.
* Not to apply schema changes.

Upgrade Steps
=============

Check the cluster schema
-------------------------
Make sure that all nodes have the schema synchronized before upgrade. The upgrade 
procedure will fail if there is a schema disagreement between nodes.

.. code:: sh

   nodetool describecluster

Drain the nodes and backup the data
-----------------------------------

Before any major procedure, like an upgrade, it is recommended to backup all 
the data to an external device. In ScyllaDB, you can backup the data using 
the ``nodetool snapshot`` command. For **each** node in the cluster, run 
the following command:

.. code:: sh

   nodetool drain
   nodetool snapshot

Take note of the directory name that nodetool gives you, and copy all the directories 
having that name under ``/var/lib/scylla`` to a backup device.

When the upgrade is completed on all nodes, remove the snapshot with the 
``nodetool clearsnapshot -t <snapshot>`` command to prevent running out of space.

Backup the configuration file
------------------------------

.. code:: sh

   sudo cp -a /etc/scylla/scylla.yaml /etc/scylla/scylla.yaml.backup-src

Gracefully stop the node
------------------------

.. code:: sh

   sudo service scylla-server stop

Download and install the new release
------------------------------------

Before upgrading, check what version you are running now using ``scylla --version``. 
You should use the same version as this version in case you want to |ROLLBACK|_ 
the upgrade. 

.. tabs::

   .. group-tab:: Debian/Ubuntu

        #. Update the |SCYLLA_DEB_NEW_REPO| to |NEW_VERSION|.
        #. Configure Java 1.8:

            .. code-block:: console

               sudo apt-get update
               sudo apt-get install -y openjdk-8-jre-headless
               sudo update-java-alternatives -s java-1.8.0-openjdk-amd64

        #. Install the new ScyllaDB version:

            .. code-block:: console

               sudo apt-get clean all
               sudo apt-get update
               sudo apt-get remove scylla\*
               sudo apt-get install scylla-enterprise
               sudo systemctl daemon-reload

        Answer ‘y’ to the first two questions.

   .. group-tab:: RHEL/CentOS

        #. Update the |SCYLLA_RPM_NEW_REPO|_  to |NEW_VERSION|.
        #. Install the new ScyllaDB version:

            .. code:: sh

               sudo yum clean all
               sudo rm -rf /var/cache/yum
               sudo yum remove scylla\*
               sudo yum install scylla-enterprise

   .. group-tab:: EC2/GCP/Azure Ubuntu Image
      
      If you’re using the ScyllaDB official image (recommended), see
      the **Debian/Ubuntu** tab for upgrade instructions. If you’re using your
      own image and have installed ScyllaDB packages for Ubuntu or Debian,
      you need to apply an extended upgrade procedure:
      
      #. Update the ScyllaDB deb repo (see above).
      #. Configure Java 1.8 (see above).
      #. Install the new ScyllaDB version with the additional 
         ``scylla-enterprise-machine-image`` package:

        .. code::
         
         sudo apt-get clean all
         sudo apt-get update
         sudo apt-get dist-upgrade scylla-enterprise
         sudo apt-get dist-upgrade scylla-enterprise-machine-image

      #. Run ``scylla_setup`` without running ``io_setup``.
      #. Run ``sudo /opt/scylladb/scylla-machine-image/scylla_cloud_io_setup``.

Start the node
--------------

.. code:: sh

   sudo service scylla-server start

Validate
--------
#. Check cluster status with ``nodetool status`` and make sure **all** nodes, including 
   the one you just upgraded, are in ``UN`` status.
#. Use ``curl -X GET "http://localhost:10000/storage_service/scylla_release_version"`` 
   to check the ScyllaDB version. Validate that the version matches the one you upgraded to.
#. Check scylla-server log (using ``journalctl _COMM=scylla``) and ``/var/log/syslog`` 
   to validate there are no new errors in the log.
#. Check again after two minutes to validate that no new issues are introduced.

Once you are sure the node upgrade was successful, move to the next node in the cluster.

Rollback Procedure
==================

.. warning::

   The rollback procedure can only be applied if some nodes have **not** been upgraded 
   to |NEW_VERSION| yet. As soon as the last node in the rolling upgrade procedure is 
   started with |NEW_VERSION|, rollback becomes impossible. At that point, the only way 
   to restore a cluster to |SRC_VERSION| is by restoring it from backup.

The following procedure describes a rollback from |SCYLLA_NAME| |NEW_VERSION|.x to 
|SRC_VERSION|.y. Apply this procedure if an upgrade from |SRC_VERSION| to |NEW_VERSION| 
failed before completing on all nodes.

* Use this procedure only for nodes you upgraded to |NEW_VERSION|.
* Execute the commands one node at a time, moving to the next node
  only after the rollback procedure is completed successfully.

ScyllaDB rollback is a rolling procedure that does **not** require a full cluster shutdown.
For each of the nodes you rollback to |SRC_VERSION|, you will:

* Drain the node and stop ScyllaDB
* Retrieve the old ScyllaDB packages
* Restore the configuration file
* Restore system tables
* Reload systemd configuration
* Restart ScyllaDB
* Validate the rollback success

Apply the procedure **serially** on each node. Do not move to the next node
before validating that the rollback was successful and the node is up and
running the old version.

Rollback Steps
==============

Drain and gracefully stop the node
----------------------------------

.. code:: sh

   nodetool drain
   sudo service scylla-server stop

Download and install the old release
------------------------------------

.. tabs::

   .. group-tab:: Debian/Ubuntu

        #. Remove the old repo file.

            .. code:: sh

               sudo rm -rf /etc/apt/sources.list.d/scylla.list

        #. Update the |SCYLLA_DEB_SRC_REPO| to |SRC_VERSION|.
        #. Install:

            .. code-block::

               sudo apt-get update
               sudo apt-get remove scylla\* -y
               sudo apt-get install scylla

        Answer ‘y’ to the first two questions.

   .. group-tab:: RHEL/CentOS

        #. Remove the old repo file.

            .. code:: sh

               sudo rm -rf /etc/yum.repos.d/scylla.repo

        #. Update the |SCYLLA_RPM_SRC_REPO|_  to |SRC_VERSION|.
        #. Install:

            .. code:: console

               sudo yum clean all
               sudo yum remove scylla\*
               sudo yum install scylla

.. note::
  
   If you are running a ScyllaDB Enterprise official image (for EC2 AMI, GCP, or Azure), follow the instructions for Ubuntu.

Restore the configuration file
------------------------------

.. code:: sh

   sudo rm -rf /etc/scylla/scylla.yaml
   sudo cp -a /etc/scylla/scylla.yaml.backup-src | /etc/scylla/scylla.yaml

Restore system tables
---------------------

Restore all tables of **system** and **system_schema** from the previous snapshot because 
|NEW_VERSION| uses a different set of system tables. 
See :doc:`Restore from a Backup and Incremental Backup </operating-scylla/procedures/backup-restore/restore/>` 
for reference.

.. code:: console

    
    cd /var/lib/scylla/data/keyspace_name/table_name-UUID/
    sudo find . -maxdepth 1 -type f  -exec sudo rm -f "{}" +
    cd /var/lib/scylla/data/keyspace_name/table_name-UUID/snapshots/<snapshot_name>/
    sudo cp -r * /var/lib/scylla/data/keyspace_name/table_name-UUID/
    sudo chown -R scylla:scylla /var/lib/scylla/data/keyspace_name/table_name-UUID/

Reload systemd configuration
----------------------------

You must reload the unit file if the systemd unit file is changed.

.. code:: sh

   sudo systemctl daemon-reload

Start the node
--------------

.. code:: sh

   sudo service scylla-server start

Validate
--------

Check the upgrade instructions above for validation. Once you are sure the node rollback 
is successful, move to the next node in the cluster.