A database can be upgraded from a minor version to the next, e.g. 1.1 → 1.2, and 1.2 → 1.3, but you can not jump directly from 1.1 → 1.3. For version 1.8 in particular, it is possible to upgrade directly from version 1.5.3 and later, as an explicit upgrade. The upgrade process is a one way step; databases cannot be downgraded.
For most upgrades, only small changes are required to the database store, and these changes proceed automatically when you start up the database using the newer version of Neo4j.
However, some upgrades require more significant changes to the database store. In these cases, Neo4j will refuse to start without explicit configuration to allow the upgrade.
The table below lists recent Neo4j versions, and the type of upgrade required.
Upgrade process for Neo4j version
From Version | To Version | Upgrade Type |
---|---|---|
1.3 | 1.4 | Automatic |
1.4 | 1.5 | Explicit |
1.5 | 1.6 | Explicit |
1.6 | 1.7 | Automatic |
1.7 | 1.8 | Automatic |
1.8 | 1.9 | Automatic |
Note | |
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Downgrade is supported only between versions which do not have incompatible store layouts.
That means that if you did an upgrade where you didn’t have to explicitly set the |
To perform a normal upgrade (for minor changes to the database store):
To perform a special upgrade (for significant changes to the database store):
allow_store_upgrade=true
" in your neo4j.properties or embedded configuration
allow_store_upgrade=true
" configuration parameter should be removed, set to "false
" or commented out
There are no store format changes between these versions so upgrading standalone instances simply consists of starting the database with the newer version. In the case of High Availability (HA) installations, the communication protocol and the master election algorithm have changed and a new "rolling upgrade" feature has been added, removing the need to shut down the entire cluster. For more information, refer to the "Upgrading a Neo4j HA Cluster" chapter of the HA section of the Neo4j manual.
There are no store format changes between these versions so upgrading standalone instances simply consists of starting the database with the newer version. In the case of High Availability (HA) installations, the communication protocol and the master election algorithm have changed and a new "rolling upgrade" feature has been added, removing the need to shut down the entire cluster. For more information, refer to the "Upgrading a Neo4j HA Cluster" chapter of the HA section of the Neo4j manual.
There are no store format changes between these versions, which means there is no particular procedure you need to upgrade a single instance.
In an HA environment these steps need to be performed:
This upgrade changes lucene version from 3.1 to 3.5. The upgrade itself is done by Lucene by loading an index.
In an HA environment these steps need to be performed:
This upgrade includes a significant change to the layout of property store files, which reduces their size on disk, and improves IO performance. To achieve this layout change, the upgrade process takes some time to process the whole of the existing database. You should budget for several minutes per gigabyte of data as part of your upgrade planning.
Warning | |
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The upgrade process for this upgrade temporarily requires additional disk space, for the period while the upgrade is in progress. Before starting the upgrade to Neo4j 1.5, you should ensure that the machine performing the upgrade has free space equal to the current size of of the database on disk. You can find the current space occupied by the database by inspecting the store file directory (data/graph.db is the default location in Neo4j server). Once the upgrade is complete, this additional space is no longer required. |
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