This page provides a complete reference to the Neo4j configuration settings, which can be set in neo4j.conf . Refer to The neo4j.conf file for details on how to use configuration settings.

Some of the settings are labeled Dynamic , which means that they can be changed at runtime, without restarting the service. For more information on how to update dynamic configuration settings, see Update dynamic settings .

Changes to the configuration at runtime are not persisted. To avoid losing changes when restarting Neo4j, make sure you update neo4j.conf as well.

In a clustered environment, CALL dbms.setConfigValue affects only the server it is run against, and it is not propagated to other members. If you want to change the configuration settings on all cluster members, you have to run the procedure against each of them and update their neo4j.conf file.

Checkpointing is the process of flushing all pending page updates from the page cache to the store files. This is done periodically and is used to recover the database in case of a crash. The checkpoint settings control the frequency of checkpoints, and the amount of data that is written to disk in each checkpoint. See also, Transaction log settings .

db.checkpoint

Configures the general policy for when checkpoints should occur. The default policy is the 'periodic' checkpoint policy, as specified by the db.checkpoint.interval.tx and db.checkpoint.interval.time settings. The Neo4j Enterprise Edition provides two alternative policies: The first is the 'continuous' checkpoint policy, which will ignore those settings and run the checkpoint process all the time. The second is the 'volumetric' checkpoint policy, which makes a best-effort at checkpointing often enough so that the database doesn’t get too far behind on deleting old transaction logs in accordance with the db.tx_log.rotation.retention_policy setting.

Valid values

one of [PERIODIC, CONTINUOUS, VOLUME, VOLUMETRIC]

Default value

PERIODIC

Description

Configures the time interval between checkpoints. The database will not checkpoint more often than this (unless checkpointing is triggered by a different event), but might checkpoint less often than this interval, if performing a checkpoint takes longer time than the configured interval. A checkpoint is a point in the transaction logs, which recovery would start from. Longer checkpoint intervals typically mean that recovery will take longer to complete in case of a crash. On the other hand, a longer checkpoint interval can also reduce the I/O load that the database places on the system, as each checkpoint implies a flushing and forcing of all the store files.

Valid values

a duration (Valid units are: ns , μs , ms , s , m , h and d ; default unit is s )

Default value

Description

Configures the transaction interval between checkpoints. The database will not checkpoint more often than this (unless check pointing is triggered by a different event), but might checkpoint less often than this interval, if performing a checkpoint takes longer time than the configured interval. A checkpoint is a point in the transaction logs, which recovery would start from. Longer checkpoint intervals typically mean that recovery will take longer to complete in case of a crash. On the other hand, a longer checkpoint interval can also reduce the I/O load that the database places on the system, as each checkpoint implies a flushing and forcing of all the store files. The default is '100000' for a checkpoint every 100000 transactions.

Valid values

an integer which is minimum 1

Default value

100000

Description

Configures the volume of transaction logs between checkpoints. The database will not checkpoint more often than this (unless check pointing is triggered by a different event), but might checkpoint less often than this interval, if performing a checkpoint takes longer time than the configured interval. A checkpoint is a point in the transaction logs, which recovery would start from. Longer checkpoint intervals typically mean that recovery will take longer to complete in case of a crash. On the other hand, a longer checkpoint interval can also reduce the I/O load that the database places on the system, as each checkpoint implies a flushing and forcing of all the store files.

Valid values

a byte size (valid multipliers are B , KiB , KB , K , kB , kb , k , MiB , MB , M , mB , mb , m , GiB , GB , G , gB , gb , g , TiB , TB , PiB , PB , EiB , EB ) which is minimum 1.00KiB

Default value

250.00MiB

Description

Limit the number of IOs the background checkpoint process will consume per second. This setting is advisory, is ignored in Neo4j Community Edition, and is followed to best effort in Enterprise Edition. An IO is in this case a 8 KiB (mostly sequential) write. Limiting the write IO in this way will leave more bandwidth in the IO subsystem to service random-read IOs, which is important for the response time of queries when the database cannot fit entirely in memory. The only drawback of this setting is that longer checkpoint times may lead to slightly longer recovery times in case of a database or system crash. A lower number means lower IO pressure, and consequently longer checkpoint times. Set this to -1 to disable the IOPS limit and remove the limitation entirely; this will let the checkpointer flush data as fast as the hardware will go. Removing the setting, or commenting it out, will set the default value of 600.

Valid values

an integer

Default value

The cluster settings are used to configure the behavior of a Neo4j cluster. For more information, see also Clustering settings .

db.cluster.catchup.pull_interval

Minimum number of machines initially required to form a clustered DBMS. The cluster is considered formed when at least this many members have discovered each other, bound together and bootstrapped a highly available system database. As a result, at least this many of the cluster’s initial machines must have server.cluster.system_database_mode set to 'PRIMARY'.NOTE: If dbms.cluster.discovery.resolver_type is set to 'LIST' and dbms.cluster.discovery.endpoints is empty then the user is assumed to be deploying a standalone DBMS, and the value of this setting is ignored.

Valid values

an integer which is minimum 2

Default value

Description

Network compression algorithms that this instance will allow in negotiation as a comma-separated list. Listed in descending order of preference for incoming connections. An empty list implies no compression. For outgoing connections this merely specifies the allowed set of algorithms and the preference of the remote peer will be used for making the decision. Allowable values: [Gzip, Snappy, Snappy_validating, LZ4, LZ4_high_compression, LZ_validating, LZ4_high_compression_validating]

Valid values

a ',' separated list with elements of type 'a string'.

Default value

Description

Which strategy to use when transferring database leaderships around a cluster. This can be one of equal_balancing or no_balancing . equal_balancing automatically ensures that each Core server holds the leader role for an equal number of databases. no_balancing prevents any automatic balancing of the leader role. Note that if a leadership_priority_group is specified for a given database, the value of this setting will be ignored for that database.

Valid values

one of [NO_BALANCING, EQUAL_BALANCING]

Default value

EQUAL_BALANCING

Connection settings control the communication between servers and between a server and a client. Neo4j provides support for Bolt, HTTP, and HTTPS protocols via connectors. For more information about the connectors, see Configure connectors .

When configuring the HTTPS or Bolt , see also Security settings and SSL framework for details on how to work with SSL certificates.

server.bolt.advertised_address

Routing strategy for neo4j:// protocol connections. Default is CLIENT , using client-side routing, with server-side routing as a fallback (if enabled). When set to SERVER , client-side routing is short-circuited, and requests will rely on server-side routing (which must be enabled for proper operation, i.e. dbms.routing.enabled =true ). Can be overridden by dbms.routing.client_side.enforce_for_domains .

Valid values

one of [SERVER, CLIENT]

Default value

CLIENT

Socket connection timeout. A timeout of zero is treated as an infinite timeout and will be bound by the timeout configured on the operating system level.

Valid values

a duration (Valid units are: ns , μs , ms , s , m , h and d ; default unit is s )

Default value

Description

Pooled connections older than this threshold will be closed and removed from the pool. Setting this option to a low value will cause a high connection churn and might result in a performance hit. It is recommended to set maximum lifetime to a slightly smaller value than the one configured in network equipment (load balancer, proxy, firewall, etc. can also limit maximum connection lifetime). Zero and negative values result in lifetime not being checked.

Valid values

a duration (Valid units are: ns , μs , ms , s , m , h and d ; default unit is s )

Default value

Description

Maximum amount of time spent attempting to acquire a connection from the connection pool. This timeout only kicks in when all existing connections are being used and no new connections can be created because maximum connection pool size has been reached. Error is raised when connection can’t be acquired within configured time. Negative values are allowed and result in unlimited acquisition timeout. Value of 0 is allowed and results in no timeout and immediate failure when connection is unavailable.

Valid values

a duration (Valid units are: ns , μs , ms , s , m , h and d ; default unit is s )

Default value

Description

Pooled connections that have been idle in the pool for longer than this timeout will be tested before they are used again, to ensure they are still alive. If this option is set too low, an additional network call will be incurred when acquiring a connection, which causes a performance hit. If this is set high, no longer live connections might be used which might lead to errors. Hence, this parameter tunes a balance between the likelihood of experiencing connection problems and performance Normally, this parameter should not need tuning. Value 0 means connections will always be tested for validity.

Valid values

a duration (Valid units are: ns , μs , ms , s , m , h and d ; default unit is s )

Default value

No connection liveliness check is done by default.

Description

Configure if the dbms.routing.getRoutingTable() procedure should include non-writer primaries as read endpoints or return only secondaries. Note: if there are no secondaries for the given database primaries are returned as read end points regardless the value of this setting. Defaults to true so that non-writer primaries are available for read-only queries in a typical heterogeneous setup.

Valid values

a boolean

Default value

The Cypher settings affect the behavior of Cypher queries. They can be used to tune the performance of Cypher queries or to restrict the kinds of queries that can be executed. For more information, see Statistics and execution plans .

dbms.cypher.forbid_exhaustive_shortestpath

The minimum time between possible Cypher query replanning events. After this time, the graph statistics will be evaluated, and if they have changed by more than the value set by dbms.cypher.statistics_divergence_threshold , the query will be replanned. If the statistics have not changed sufficiently, the same interval will need to pass before the statistics will be evaluated again. Each time they are evaluated, the divergence threshold will be reduced slightly until it reaches 10% after 7h, so that even moderately changing databases will see query replanning after a sufficiently long time interval.

Valid values

a duration (Valid units are: ns , μs , ms , s , m , h and d ; default unit is s )

Default value

If any of the underlying statistics used to create the plan have changed more than this value, the plan will be considered stale and will be replanned. Change is calculated as abs(a-b)/max(a,b) .

This means that a value of 0.75 requires the database to quadruple in size before query replanning. A value of 0 means that the query will be replanned as soon as there is any change in statistics and the replan interval has elapsed.

This interval is defined by dbms.cypher.min_replan_interval and defaults to 10s. After this interval, the divergence threshold will slowly start to decline, reaching 10% after about 7h. This will ensure that long running databases will still get query replanning on even modest changes, while not replanning frequently unless the changes are very large.

Valid values

a double which is in the range 0.0 to 1.0

Default value

Database settings affect the behavior of a Neo4j database, for example, the file watcher service, the database format, the database store files, and the database timezone. They can be varied between each database but must be consistent across all configuration files in a cluster/DBMS.

db.filewatcher.enabled

initial.dbms.default_database

To set the default database, use the dbms.setDefaultDatabase() procedure instead.

Description

Databases may be created from an existing 'seed' (a database backup or dump) stored at some source URI. Different types of seed source are supported by different implementations of com.neo4j.dbms.seeding.SeedProvider . For example, seeds stored at s3:// and https:// URIs are supported by the builtin S3SeedProvider and URLConnectionSeedProvider respectively. This list specifies enabled seed providers. If a seed source (URI scheme) is supported by multiple providers in the list, the first matching provider will be used. If the list is set to empty, the seed from uri functionality is effectively disabled.

Valid values

a , separated list with elements of type a string .

Default value

S3SeedProvider

The import settings control the size of the internal buffer used by LOAD CSV and the escaping of quotes in CSV files.

db.import.csv.buffer_size

Selects whether to conform to the standard https://tools.ietf.org/html/rfc4180 for interpreting escaped quotation characters in CSV files loaded using LOAD CSV . Setting this to false will use the standard, interpreting repeated quotes '""' as a single in-lined quote, while true will use the legacy convention originally supported in Neo4j 3.0 and 3.1, allowing a backslash to include quotes in-lined in fields.

Valid values

a boolean

Default value

The index settings control the fulltext index and the background index sampling (chunk size limit and sample size). For more information, see Index configuration .

db.index.fulltext.default_analyzer

Neo4j has two different configuration files for logging, one for the neo4j.log , which contains general information about Neo4j, and one configuration file for all other types of logging via Log4j 2 (except gc.log which is handled by the Java Virtual Machine(JVM). For more information, see Logging .

db.logs.query.annotation_data_as_json_enabled

log queries at the end of execution, that take longer than the configured threshold, db.logs.query.threshold .

log queries at the start and end of execution, regardless of db.logs.query.threshold .

Description

Obfuscates all literals of the query before writing to the log. Note that node labels, relationship types and map property keys are still shown. Changing the setting will not affect queries that are cached. So, if you want the switch to have an immediate effect, you must also call CALL db.clearQueryCaches() .

Valid values

a boolean

Default value

false

Description

Log the start and end of a transaction. Valid values are 'OFF', 'INFO', or 'VERBOSE'. OFF: no logging. INFO: log the start and end of transactions that take longer than the configured threshold, db.logs.query.transaction.threshold . VERBOSE: log the start and end of all transactions. Log entries are written to the query log.

Valid values

one of [OFF, INFO, VERBOSE]

Default value

Memory settings control how much memory is allocated to Neo4j and how it is used. It is recommended to perform a certain amount of testing and tuning of these settings to figure out the optimal division of the available memory. For more information on how to tune these settings, see Memory configuration , Disks, RAM and other tips , and Tuning of the garbage collector .

db.memory.pagecache.warmup.enable

server.memory.query_cache.per_db_cache_num_entries

Description

Defines the size of the off-heap memory blocks cache. The cache will contain this number of blocks for each block size that is power of two. Thus, maximum amount of memory used by blocks cache can be calculated as 2 * server.memory.off_heap.max_cacheable_block_size * server.memory.off_heap.block_cache_size

Valid values

an integer which is minimum 16

Default value

Description

Page cache can be configured to use a temporal buffer for flushing purposes. It is used to combine, if possible, sequence of several cache pages into one bigger buffer to minimize the number of individual IOPS performed and better utilization of available I/O resources, especially when those are restricted.

Valid values

a boolean

Default value

false

Description

Page cache can be configured to use a temporal buffer for flushing purposes. It is used to combine, if possible, sequence of several cache pages into one bigger buffer to minimize the number of individual IOPS performed and better utilization of available I/O resources, especially when those are restricted. Use this setting to configure individual file flush the buffer size in pages (8KiB). To be able to utilize this buffer during page cache flushing, buffered flush should be enabled.

Valid values

an integer which is in the range 1 to 512

Default value

Description

The amount of memory to use for mapping the store files. If Neo4j is running on a dedicated server, then it is generally recommended to leave about 2-4 gigabytes for the operating system, give the JVM enough heap to hold all your transaction state and query context, and then leave the rest for the page cache. If no page cache memory is configured, then a heuristic setting is computed based on available system resources.

Valid values

a byte size (valid multipliers are B , KiB , KB , K , kB , kb , k , MiB , MB , M , mB , mb , m , GiB , GB , G , gB , gb , g , TiB , TB , PiB , PB , EiB , EB )

Default value

By default the size of page cache will be 50% och available RAM minus the max heap size.The size of the page cache will also not be larger than 70x the max heap size (due to some overhead of the page cache in the heap.

Enable sharing cache space between different databases. With this option turned on, databases will share cache space, but not cache entries. This means that a database may store and retrieve entries from the shared cache, but it may not retrieve entries produced by another database. The database may, however, evict entries from other databases as necessary, according to the constrained cache size and cache eviction policy. In essence, databases may compete for cache space, but may not observe each other’s entries.

When this option is turned on, the cache space available to all databases is configured with server.memory.query_cache.shared_cache_num_entries . With this option turned off, the cache space available to each individual database is configured with server.memory.query_cache.per_db_cache_num_entries .

Valid values

a boolean

Default value

false

The number of cached queries for all databases. The maximum number of queries that can be kept in a cache is exactly server.memory.query_cache.shared_cache_num_entries . This setting is only deciding cache size when server.memory.query_cache.sharing_enabled is set to true .

Valid values

a integer

Default value

The number of cached queries per database. The maximum number of queries that can be kept in a cache is number of databases * server.memory.query_cache.per_db_cache_num_entries . With 10 databases and server.memory.query_cache.per_db_cache_num_entries =1000, the cache can keep 10000 plans in total. This setting is only deciding cache size when server.memory.query_cache.sharing_enabled is set to false .

Valid values

a integer

Default value

The metrics settings control whether Neo4j will log metrics, what metrics to log, how to log them, and how to expose them. For better understanding of the metrics settings and how to configure them, see Metrics .

server.metrics.csv.enabled

The Kubernetes settings are used to configure a cluster running on Kubernetes , where each server is running as a Kubernetes service. The addresses of the other servers can be obtained using the List Service API, as described in the Kubernetes API documentation . For more information, see Discovery in Kubernetes .

dbms.kubernetes.address

The security settings are used to configure the security of your Neo4j deployment. Refer to the Security section for thorough information on security in Neo4j.

dbms.security.allow_csv_import_from_file_urls

The maximum number of unsuccessful authentication attempts before imposing a user lock for the configured amount of time, as defined by dbms.security.auth_lock_time .The locked out user will not be able to log in until the lock period expires, even if correct credentials are provided. Setting this configuration option to values less than 3 is not recommended because it might make it easier for an attacker to brute force the password.

Valid values

an integer which is minimum 0

Default value

Description

A list of security authentication providers containing the users and roles. This can be any of the built-in native or ldap providers, or it can be an externally provided plugin, with a custom name prefixed by plugin- , i.e. plugin-<AUTH_PROVIDER_NAME> . They will be queried in the given order when login is attempted.

Valid values

a ',' separated list with elements of type 'a string'.

Default value

native

Description

A list of security authorization providers containing the users and roles. This can be any of the built-in native or ldap providers, or it can be an externally provided plugin, with a custom name prefixed by plugin- , i.e. plugin-<AUTH_PROVIDER_NAME> . They will be queried in the given order when login is attempted.

Valid values

a ',' separated list with elements of type 'a string'.

Default value

native

Description

Value of the HTTP Strict-Transport-Security (HSTS) response header. This header tells browsers that a webpage should only be accessed using HTTPS instead of HTTP. It is attached to every HTTPS response. Setting is not set by default so 'Strict-Transport-Security' header is not sent. Value is expected to contain directives like 'max-age', 'includeSubDomains' and 'preload'.

Valid values

a string

Default value

Description

Determines if the result of authentication via the LDAP server should be cached or not. Caching is used to limit the number of LDAP requests that have to be made over the network for users that have already been authenticated successfully. A user can be authenticated against an existing cache entry (instead of via an LDAP server) as long as it is alive (see dbms.security.auth_cache_ttl ). An important consequence of setting this to true is that Neo4j then needs to cache a hashed version of the credentials in order to perform credentials matching. This hashing is done using a cryptographic hash function together with a random salt. Preferably a conscious decision should be made if this method is considered acceptable by the security standards of the organization in which this Neo4j instance is deployed.

Valid values

a boolean

Default value

Description

LDAP user DN template. An LDAP object is referenced by its distinguished name (DN), and a user DN is an LDAP fully-qualified unique user identifier. This setting is used to generate an LDAP DN that conforms with the LDAP directory’s schema from the user principal that is submitted with the authentication token when logging in. The special token {0} is a placeholder where the user principal will be substituted into the DN string.

Valid values

a string which Must be a string containing '{0}' to understand where to insert the runtime authentication principal.

Default value

uid={0},ou=users,dc=example,dc=com

Description

The LDAP group to which a user must belong to get any access to the system.Set this to restrict access to a subset of LDAP users belonging to a particular group. If this is not set, any user to successfully authenticate via LDAP will have access to the PUBLIC role and any other roles assigned to them via dbms.security.ldap.authorization.group_to_role_mapping .

Valid values

a string

Default value

Description

An authorization mapping from LDAP group names to Neo4j role names. The map should be formatted as a semicolon separated list of key-value pairs, where the key is the LDAP group name and the value is a comma separated list of corresponding role names. For example: group1=role1;group2=role2;group3=role3,role4,role5 You could also use whitespaces and quotes around group names to make this mapping more readable, for example:

`dbms.security.ldap.authorization.group_to_role_mapping`=\
         "cn=Neo4j Read Only,cn=users,dc=example,dc=com"      = reader;    \
         "cn=Neo4j Read-Write,cn=users,dc=example,dc=com"     = publisher; \
         "cn=Neo4j Schema Manager,cn=users,dc=example,dc=com" = architect; \
         "cn=Neo4j Administrator,cn=users,dc=example,dc=com"  = admin

Description

This setting determines whether multiple LDAP search results will be processed (as is required for the lookup of nested groups). If set to true then instead of using attributes on the user object to determine group membership (as specified by dbms.security.ldap.authorization.group_membership_attributes ), the user object will only be used to determine the user’s Distinguished Name, which will subsequently be used with dbms.security.ldap.authorization.user_search_filter in order to perform a nested group search. The Distinguished Names of the resultant group search results will be used to determine roles.

Valid values

a boolean

Default value

false

Description

The search template which will be used to find the nested groups which the user is a member of. The filter should contain the placeholder token {0} which will be substituted with the user’s Distinguished Name (which is found for the specified user principle using dbms.security.ldap.authorization.user_search_filter ). The default value specifies Active Directory’s LDAP_MATCHING_RULE_IN_CHAIN (aka 1.2.840.113556.1.4.1941) implementation which will walk the ancestry of group membership for the specified user.

Valid values

a string

Default value

(&(objectclass=group)(member:1.2.840.113556.1.4.1941:={0}))

Description

Perform LDAP search for authorization info using a system account instead of the user’s own account. If this is set to false (default), the search for group membership will be performed directly after authentication using the LDAP context bound with the user’s own account. The mapped roles will be cached for the duration of dbms.security.auth_cache_ttl , and then expire, requiring re-authentication. To avoid frequently having to re-authenticate sessions you may want to set a relatively long auth cache expiration time together with this option. NOTE: This option will only work if the users are permitted to search for their own group membership attributes in the directory. If this is set to true , the search will be performed using a special system account user with read access to all the users in the directory. You need to specify the username and password using the settings dbms.security.ldap.authorization.system_username and dbms.security.ldap.authorization.system_password with this option. Note that this account only needs read access to the relevant parts of the LDAP directory and does not need to have access rights to Neo4j, or any other systems.

Valid values

a boolean

Default value

false

Description

URL of LDAP server to use for authentication and authorization. The format of the setting is <protocol>://<hostname>:<port> , where hostname is the only required field. The supported values for protocol are ldap (default) and ldaps . The default port for ldap is 389 and for ldaps 636. For example: ldaps://ldap.example.com:10389 . You may want to consider using STARTTLS ( dbms.security.ldap.use_starttls ) instead of LDAPS for secure connections, in which case the correct protocol is ldap .

Valid values

a string

Default value

localhost

dbms.security.oidc.<provider>.authorization.group_to_role_mapping

dbms.security.oidc.<provider>.authorization.group_to_role_mapping=\
         "Neo4j Read Only"      = reader;    \
         "Neo4j Read-Write"     = publisher; \
         "Neo4j Schema Manager" = architect; \
         "Neo4j Administrator"  = admin

  client_id: the SSO Idp client idenfifier.
  response_type: code if auth_flow is pkce or token for implicit auth_flow.
  scope: often containing a subset of 'email profile openid groups'.

The server directories settings can be used to change the default locations of your Neo4j files. For more information, see Default file locations .

server.directories.cluster_state

server.backup.enabled

The transaction settings helps you manage the transactions in your database, for example, the transaction timeout, the lock acquisition timeout, the maximum number of concurrently running transactions, etc. For more information, see Manage transactions and Locks and deadlocks .

db.lock.acquisition.timeout

See also Checkpoint settings .

db.recovery.fail_on_missing_files

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