Back up and restore a database in Causal Cluster

This tutorial provides a detailed example of how to back up and restore a database in a running Causal Cluster.

The following example assumes that you want to restore a database backup, which has users and roles associated with it, in a running Causal Cluster with three core servers. For more information on how to set up a Causal Cluster with three cores, see Set up a local Causal Cluster.

In a Neo4j DBMS, every database is backed up individually. Therefore, it is very important to plan your backup strategy for each of them. For more detailed information on how to design an appropriate backup strategy for your setup, see Backup and restore.

1. Prepare to back up your database

Before you perform the backup, it is good to take a note of the data and metadata of the database that you want to restore. You can use this information to later verify that the restore is successful and to recreate the database users and roles. In this example, the database is called movies1 and uses the Movie Graph dataset from the Neo4j Browser → Favorites → Example Graphs.

This tutorial uses the Linux or macOS tarball installation. It assumes that your current work directory is the <neo4j-home> directory of the tarball installation.

  1. In the Neo4j instance, where the database is running, log in to the Cypher Shell command-line console with your credentials. For more information about the Cypher Shell command-line interface (CLI) and how to use it, see Cypher Shell.

    bin/cypher-shell -u neo4j -p <password>
    Connected to Neo4j at neo4j://localhost:7687 as user neo4j.
    Type :help for a list of available commands or :exit to exit the shell.
    Note that Cypher queries must end with a semicolon.
  2. Change the active database to movies1.

    :use movies1
  3. Run a query to count the number of nodes in the database.

    MATCH (n) RETURN count(n) AS countNode;
    +-----------+
    | countNode |
    +-----------+
    | 171       |
    +-----------+
    
    1 row available after 22 ms, consumed after another 1 ms
  4. Run a query to count the number of relationships.

    MATCH (n)-[r]->() RETURN count(r) AS countRelationships;
    +--------------------+
    | countRelationships |
    +--------------------+
    | 253                |
    +--------------------+
    
    1 row available after 29 ms, consumed after another 0 ms
  5. Change the active database to system, and run a query to see if there are any custom roles, associated with this database, and their privileges.

    SHOW ALL PRIVILEGES AS COMMANDS;
    +-------------------------------------------------------------+
    | command                                                     |
    +-------------------------------------------------------------+
    | "GRANT ACCESS ON HOME DATABASE TO `PUBLIC`"                 |
    | "GRANT EXECUTE FUNCTION * ON DBMS TO `PUBLIC`"              |
    | "GRANT EXECUTE PROCEDURE * ON DBMS TO `PUBLIC`"             |
    | "GRANT ACCESS ON DATABASE * TO `admin`"                     |
    | "GRANT MATCH {*} ON GRAPH * NODE * TO `admin`"              |
    | "GRANT MATCH {*} ON GRAPH * RELATIONSHIP * TO `admin`"      |
    | "GRANT WRITE ON GRAPH * TO `admin`"                         |
    | "GRANT NAME MANAGEMENT ON DATABASE * TO `admin`"            |
    | "GRANT INDEX MANAGEMENT ON DATABASE * TO `admin`"           |
    | "GRANT CONSTRAINT MANAGEMENT ON DATABASE * TO `admin`"      |
    | "GRANT START ON DATABASE * TO `admin`"                      |
    | "GRANT STOP ON DATABASE * TO `admin`"                       |
    | "GRANT TRANSACTION MANAGEMENT (*) ON DATABASE * TO `admin`" |
    | "GRANT ALL DBMS PRIVILEGES ON DBMS TO `admin`"              |
    | "GRANT ACCESS ON DATABASE * TO `architect`"                 |
    | "GRANT MATCH {*} ON GRAPH * NODE * TO `architect`"          |
    | "GRANT MATCH {*} ON GRAPH * RELATIONSHIP * TO `architect`"  |
    | "GRANT WRITE ON GRAPH * TO `architect`"                     |
    | "GRANT NAME MANAGEMENT ON DATABASE * TO `architect`"        |
    | "GRANT INDEX MANAGEMENT ON DATABASE * TO `architect`"       |
    | "GRANT CONSTRAINT MANAGEMENT ON DATABASE * TO `architect`"  |
    | "GRANT ACCESS ON DATABASE * TO `publisher`"                 |
    | "GRANT MATCH {*} ON GRAPH * NODE * TO `publisher`"          |
    | "GRANT MATCH {*} ON GRAPH * RELATIONSHIP * TO `publisher`"  |
    | "GRANT WRITE ON GRAPH * TO `publisher`"                     |
    | "GRANT NAME MANAGEMENT ON DATABASE * TO `publisher`"        |
    | "GRANT ACCESS ON DATABASE * TO `editor`"                    |
    | "GRANT MATCH {*} ON GRAPH * NODE * TO `editor`"             |
    | "GRANT MATCH {*} ON GRAPH * RELATIONSHIP * TO `editor`"     |
    | "GRANT WRITE ON GRAPH * TO `editor`"                        |
    | "GRANT ACCESS ON DATABASE * TO `reader`"                    |
    | "GRANT MATCH {*} ON GRAPH * NODE * TO `reader`"             |
    | "GRANT MATCH {*} ON GRAPH * RELATIONSHIP * TO `reader`"     |
    | "GRANT ACCESS ON DATABASE * TO `myrole`"                    |
    | "GRANT MATCH {*} ON GRAPH * NODE * TO `myrole`"             |
    | "GRANT MATCH {*} ON GRAPH * RELATIONSHIP * TO `myrole`"     |
    | "GRANT WRITE ON GRAPH movies1 TO `myrole`"                  |
    +-------------------------------------------------------------+
    
    39 rows available after 868 ms, consumed after another 80 ms

    The result shows that there is one custom role myrole.

  6. Run a query to see all users associated with this role.

    SHOW USERS;
    +---------------------------------------------------------------------+
    | user    | roles                | passwordChangeRequired | suspended |
    +---------------------------------------------------------------------+
    | "neo4j" | ["admin", "PUBLIC"]  | FALSE                  | FALSE     |
    | "user1" | ["myrole", "PUBLIC"] | TRUE                   | FALSE     |
    +---------------------------------------------------------------------+
    
    2 rows available after 36 ms, consumed after another 2 ms
  7. Exit the Cypher Shell command-line console.

    :exit

2. Back up your database

Now you are ready to back up the database.

Run the following command to back up the database in your targeted folder. If the folder where you want to place your backup does not exist, you have to create it. In this example, it is called /tmp/4.3.2.

To perform the backup, run the following command:

bin/neo4j-admin backup --backup-dir=/tmp/4.3.2 --database=movies1 --include-metadata=all

The option --include-metadata=all creates a cypher script, which you can later use to restore the database’s users, roles, and privileges.

For details on performing a backup and the different command options, see Back up an online database.

3. Delete the database that you want to replace

Before you restore the database backup, you have to delete the database that you want to replace with that backup. If you want to restore the backup as an additional database in your DBMS, then you can proceed to Restore the database backup on all cluster members directly.

On one of the cluster members, run the Cypher command DROP DATABASE to delete the database that you want to replace. The command is automatically routed to the leader and from there to the other cluster members.

Dropping a database also deletes the users and roles associated with it.

  1. In the Cypher Shell command-line console on one of the cluster members, change the active database to system, and run the command DROP DATABASE to delete the database that you want to replace. In this example, the database is called movies.

    DROP DATABASE movies;
    0 rows available after 82 ms, consumed after another 0 ms

    If you are unable to delete the database (e.g., because Neo4j is not running), you must run neo4j-admin unbind first instead. If you fail to do this, the store files you have (post restore) will be out of sync with the cluster state you have for that database, leading to logical corruption.

  2. You can run SHOW DATABASES to verify that the database movies does not exist.

    SHOW DATABASES;
    +----------------------------------------------------------------------------------------------+
    | name     | address          | role       | requestedStatus | currentStatus | error | default |
    +----------------------------------------------------------------------------------------------+
    | "neo4j"  | "localhost:7687" | "follower" | "online"        | "online"      | ""    | TRUE    |
    | "neo4j"  | "localhost:7688" | "leader"   | "online"        | "online"      | ""    | TRUE    |
    | "neo4j"  | "localhost:7689" | "follower" | "online"        | "online"      | ""    | TRUE    |
    | "system" | "localhost:7687" | "follower" | "online"        | "online"      | ""    | FALSE   |
    | "system" | "localhost:7688" | "follower" | "online"        | "online"      | ""    | FALSE   |
    | "system" | "localhost:7689" | "leader"   | "online"        | "online"      | ""    | FALSE   |
    +----------------------------------------------------------------------------------------------+
    
    6 rows available after 7 ms, consumed after another 3 ms
  3. Exit the Cypher Shell command-line console.

    :exit

4. Restore the database backup on all cluster members

On each cluster member, run the following command to restore the database backup. For details on performing a restore and the different command options, see Restore a database backup.

bin/neo4j-admin restore --from=/tmp/4.3.2/movies1 --database=movies1
You need to execute $HOME/path/to/core-member/data/scripts/movies1/restore_metadata.cypher. To execute the file use cypher-shell command with parameter `movies1`
restorePath=/tmp/{neo4j-version-exact}/movies1, restoreStatus=successful, reason=

Then, on each cluster member, run the following command to verify that the database movies1 exists:

ls -al data/databases
total 0
drwxr-xr-x@  7 username  staff   224 17 Nov 15:50 .
drwxr-xr-x@  8 username  staff   256 17 Nov 15:50 ..
drwxr-xr-x  40 username  staff  1280 17 Nov 15:50 movies1
drwxr-xr-x  37 username  staff  1184 16 Nov 15:00 neo4j
-rw-r--r--   1 username  staff     0 16 Nov 15:00 store_lock
drwxr-xr-x  38 username  staff  1216 16 Nov 15:00 system

However, restoring a database does not automatically create it. Therefore, it will not be visible if you do SHOW DATABASES in Cypher Shell or Neo4j Browser.

5. Create the database backup on the cluster leader

You create the database backup only on one of your cluster members using the command CREATE DATABASE. The command is automatically routed to the leader and from there to the other cluster members.

  1. In the Cypher Shell command-line console on one of the cluster members, use the system database and create the database movies1.

    CREATE DATABASE movies1;
    0 rows available after 132 ms, consumed after another 0 ms
  2. Verify that the movies1 database is online on all members.

    SHOW DATABASES;
    +-----------------------------------------------------------------------------------------------+
    | name      | address          | role       | requestedStatus | currentStatus | error | default |
    +-----------------------------------------------------------------------------------------------+
    | "movies1" | "localhost:7688" | "follower" | "online"        | "online"      | ""    | FALSE   |
    | "movies1" | "localhost:7687" | "leader"   | "online"        | "online"      | ""    | FALSE   |
    | "movies1" | "localhost:7689" | "follower" | "online"        | "online"      | ""    | FALSE   |
    | "neo4j"   | "localhost:7688" | "leader"   | "online"        | "online"      | ""    | TRUE    |
    | "neo4j"   | "localhost:7687" | "follower" | "online"        | "online"      | ""    | TRUE    |
    | "neo4j"   | "localhost:7689" | "follower" | "online"        | "online"      | ""    | TRUE    |
    | "system"  | "localhost:7688" | "follower" | "online"        | "online"      | ""    | FALSE   |
    | "system"  | "localhost:7687" | "leader"   | "online"        | "online"      | ""    | FALSE   |
    | "system"  | "localhost:7689" | "follower" | "online"        | "online"      | ""    | FALSE   |
    +-----------------------------------------------------------------------------------------------+
    
    9 rows available after 3 ms, consumed after another 1 ms
  3. Exit the Cypher Shell command-line console.

    :exit

6. Recreate the database users and roles

On one of the cluster members, run the restore cypher script restore_metadata.cypher to create the database and recreate all users and roles of the database backup. The command is automatically routed to the leader and from there to the other cluster members.

Using cat (UNIX)

cat data/scripts/movies1/restore_metadata.cypher | bin/cypher-shell -u neo4j -p password -a localhost:7688 -d system --param "database => 'movies1'"

Using type (Windows)

type data\scripts\movies1\restore_metadata.cypher | bin\cypher-shell.bat -u neo4j -p password -a localhost:7688 -d system --param "database => 'movies1'"

Follow the steps from 1 to 6 of section Prepare to back up your database to verify that all data and metadata of the database backup have been successfully restored on all cluster members.