The Neo4j Manual v3.1.0-SNAPSHOT23.5. Upgrading

This section describes upgrading a single Neo4j instance. To upgrade a Neo4j HA cluster (Neo4j Enterprise), a very specific procedure must be followed. Please see Section 25.5, “Upgrade of a Neo4j HA Cluster”.

Throughout this instruction, the files used to store the Neo4j data are referred to as database files. These files is are found in the directory specified by dbms.directories.data in neo4j.conf.

Disk space requirements An upgrade requires substantial free disk space, as it makes an entire copy of the database. The upgraded database may also require larger data files overall. It is recommended to make available an extra 50% disk space on top of the existing database files. In addition to this, don’t forget to reserve the disk space needed for the pre-upgrade backup.

Upgrade instructions

1. Cleanly shut down the database if it is running.
2. Make a backup copy of the database files. If using the online backup tool available with Neo4j Enterprise, ensure that backups have completed successfully.
3. Install Neo4j 3.1.0-SNAPSHOT.
4. Review the settings in the configuration files in the previous installation, and transfer any custom settings to the 3.1.0-SNAPSHOT installation. Since many settings have been changed between Neo4j 2.x and Neo4j 3.0, it is advisable to use the config-migrator to migrate the config files for you. The config-migrator can be found in the tools directory, and can be invoked with a command like: java -jar config-migrator.jar path/to/neo4j2.3 path/to/neo4j3.0. Take note of any warnings printed, and manually review the edited config files produced.
5. Import your data from the old installation using neo4j-admin import --mode=database --database=<database-name> --from=<source-directory> (for details, see the man page).
6. If the database is not called graph.db, set dbms.active_database in neo4j.conf to the name of the database.
7. Set dbms.allow_format_migration=true in neo4j.conf of the 3.1.0-SNAPSHOT installation. Neo4j will fail to start without this configuration.
8. Start up Neo4j 3.1.0-SNAPSHOT.
9. The database upgrade will take place during startup.
10. Information about the upgrade and a progress indicator are logged into debug.log.
11. When upgrade has finished, the dbms.allow_format_migration should be set to false or be removed.
12. It is good practice to make a full backup immediately after the upgrade.

Cypher compatibility The Cypher language may evolve between Neo4j versions. For backward compatibility, Neo4j provides directives which allow explicitly selecting a previous Cypher language version. This is possible to do globally or for individual statements, as described in the