4.1. The neo4j.conf file

This section introduces the neo4j.conf file, and its syntax.

This section contains the following:

4.1.1. Introduction

The neo4j.conf file is the main source of configuration settings in Neo4j, and includes the mappings of configuration setting keys to values. The location of the neo4j.conf file in the different configurations of Neo4j is listed in Table 4.1, “The locations of important files”.

Most of the configuration settings in the neo4j.conf file apply directly to Neo4j itself, but there are also some settings which apply to the Java Runtime (the JVM) on which Neo4j runs. For more information, see the JVM specific configuration settings below. Many of the configuration settings are also used by the neo4j launcher scripts.

4.1.2. Syntax

  • The equals sign (=) maps configuration setting keys to configuration values.
  • Lines that start with the number sign (#) are handled as comments.
  • Empty lines are ignored.
  • There is no order for configuration settings, and each setting in the neo4j.conf file must be uniquely specified. If you have multiple configuration settings with the same key, but different values, this can lead to unpredictable behavior.

    The only exception to this is dbms.jvm.additional. If you set more than one value for dbms.jvm.additional, then each setting value will add another custom JVM argument to the java launcher.

4.1.3. JVM specific configuration settings

4.1.4. List currently active settings

You can use the procedure dbms.listConfig() to list the currently active configuration settings and their values.

Example 4.1. List currently active configuration settings
CALL dbms.listConfig()
YIELD name, value
WHERE name STARTS WITH 'dbms.'
RETURN name, value
ORDER BY name
LIMIT 4;
+----------------------------------------------+
| name                           | value       |
+----------------------------------------------+
| "dbms.active_database"         | "graph.db"  |
| "dbms.allow_format_migration"  | "false"     |
| "dbms.allow_upgrade"           | "false"     |
| "dbms.checkpoint"              | "periodic"  |
+----------------------------------------------+
4 rows

See also Section 4.8, “Dynamic settings” for information about dynamic settings.