In-place rolling upgrade (Docker)

This example shows how to perform an in-place rolling upgrade of a v5.x cluster running on Docker.

It is recommended to read the following pages before continuing:

For critical systems, it is recommended to:

  • Backup your server(s), including databases, configuration, and encryption keys to avoid losing data in case of failure.

  • Perform the upgrade in a test environment.

Before upgrading your cluster, ensure that it is in a healthy state. For example, this query checking for servers that are not hosting the databases they are expected to host should return no results:

SHOW SERVERS YIELD name, hosting, requestedHosting, serverId WHERE requestedHosting <> hosting

And this one checking for databases that are not in their expected state should also return no results:

SHOW DATABASES YIELD name, address, currentStatus, requestedStatus, statusMessage WHERE currentStatus <> requestedStatus RETURN name, address, currentStatus, requestedStatus, statusMessage

The following example steps are based on the following pre-upgrade state:

  • The environment has three cluster members located on three different servers a, b, c.

  • Neo4j DBMS v5.x is running in a Docker container on each server with /data directory in the container mapped to /path/to/data on the host machine and the container is named neo4j-dbms. You can achieve this, for instance, by running the following command on each server:

    docker run -d \
    --name=neo4j-dbms \
    --volume=/path/to/data:/data \
    neo4j:5.x-enterprise

Upgrade steps

  1. On server a, stop the container neo4j-dbms by running:

    docker stop neo4j-dbms

  2. Remove neo4j-dbms container:

    docker rm neo4j-dbms

  3. Start a v5.y container, named neo4j-dbms:

    docker run -d --name neo4j-dbms -v /path/to/data:data neo4j:5.y

    The upgrade process takes place during startup.

  4. Gradually repeat the same steps on servers b and c.

  5. Run CALL dbms.upgrade() against the cluster using Cypher Shell or another Cypher client.

Monitor the logs

The neo4j.log file contains information on how many steps the upgrade will involve and how far it has progressed.

Neo4j logging output is written to files in the /logs directory. This directory is mounted as a /logs volume.