Upgrading to Mender 3.6


This is a tutorial for upgrading the Mender Server from version 3.3 and 3.4 to 3.6 in production environments. There are no particular steps you should take, other than take a backup and run the new version, however there are things to look out for.

Besides the version specific guidelines below, please make sure you're following the suggested upgrade best practices to reduce the risk of unpredictable downtime and data loss.

Before you start

Current version

Be sure that your current version is either 3.3 or 3.4 and that it works, and Mender Server starts properly.

Upgrade MongoDB to 5.0 (optional)

We recommend upgrading your MongoDB deployment from 4.4 to 5.0. Please refer to the official documentation for conducting the upgrade. Mender 3.3, 3.4 and 3.6 are all compatible with both MongoDB 4.4 and 5.0.

Migrating from 3.3

Helm chart major upgrade

The helm chart is versioned separately from the Mender releases.

During the lifetime of Mender 3.4.0, the helm chart got a major version increase with a breaking change.

helm search repo mendersoftware/mender --versions

# Output
# NAME                  CHART VERSION   APP VERSION DESCRIPTION                                       
# mendersoftware/mender 5.3.0           3.6.3       Mender is a robust and secure way to update all...
# ...
# mendersoftware/mender 5.0.0           3.4.0       Mender is a robust and secure way to update all...
# mendersoftware/mender 4.0.3           3.4.0       Mender is a robust and secure way to update all...
# ...

If you're not updating the helm chart changes you might stumble onto this when doing the 3.3 -> 3.6 upgrade. To fix this issue please adjust your redis configuration to the new format.

Redis is now configured as a global service which needs to be configured.

    username: null
    password: null
    URL: ""

We strongly recommend using an external redis service provider.

As a reference, we provide redis as a dependency through a subchart. We do not provide support for troubleshooting issues related to problems with an internally deployed redis instance.

The service specific redis credentials which were used before the helm chart version 5 need to be removed:

DEVICEAUTH_REDIS_ADDR: "mender-redis:6379"

USERADM_REDIS_ADDR: "mender-redis:6379"

useradm database

Be sure that useradm database is clean. Especially look out for leftovers from previous (possible single tenant installations). They can make database migrations to fail.

Maintenance window

Be prepared for the maintenance window of approximately 15 minutes. This is the maximal estimated migration time, as seen in the biggest databases we are dealing with.

We welcome contributions to improve this documentation. To submit a change, use the Edit link at the top of the page or email us at .