# Graph Service configuration¶

NebulaGraph provides two initial configuration files for the Graph Service, nebula-graphd.conf.default and nebula-graphd.conf.production. Users can use them in different scenarios conveniently. The default file path is /usr/local/nebula/etc/.

Caution

• It is not recommended to modify the value of local_config to false. If modified, the NebulaGraph service will first read the cached configurations, which may cause configuration inconsistencies between clusters and cause unknown risks.
• It is not recommended to modify the configurations that are not introduced in this topic, unless you are familiar with the source code and fully understand the function of configurations.

## How to use the configuration files¶

To use the initial configuration file, choose one of the above two files and delete the suffix .default or .production from the initial configuration file for the Meta Service to apply the configurations defined in it.

If a parameter is not set in the configuration file, NebulaGraph uses the default value. Not all parameters are predefined. And the predefined parameters in the two initial configuration files are different. This topic uses the parameters in nebula-metad.conf.default.

Caution

Some parameter values in the configuration file can be dynamically modified during runtime. We label these parameters as Yes that supports runtime dynamic modification in this article. When the local_config value is set to true, the dynamically modified configuration is not persisted, and the configuration will be restored to the initial configuration after the service is restarted. For more information, see Modify configurations.

For all parameters and their current values, see Configurations.

## Basics configurations¶

Name Predefined value Description Whether supports runtime dynamic modifications
daemonize true When set to true, the process is a daemon process. No
pid_file pids/nebula-graphd.pid The file that records the process ID. No
enable_optimizer true When set to true, the optimizer is enabled. No
timezone_name - Specifies the NebulaGraph time zone. This parameter is not predefined in the initial configuration files. The system default value is UTC+00:00:00. For the format of the parameter value, see Specifying the Time Zone with TZ. For example, --timezone_name=UTC+08:00 represents the GMT+8 time zone. No
local_config true When set to true, the process gets configurations from the configuration files. No

Note

• While inserting property values of time types, NebulaGraph transforms time types (except TIMESTAMP) to the corresponding UTC according to the time zone specified by timezone_name. The time-type values returned by nGQL queries are all UTC time.
• timezone_name is only used to transform the data stored in NebulaGraph. Other time-related data of the NebulaGraph processes still uses the default time zone of the host, such as the log printing time.

## Logging configurations¶

Name Predefined value Description Whether supports runtime dynamic modifications
log_dir logs The directory that stores the Meta Service log. It is recommended to put logs on a different hard disk from the data. No
minloglevel 0 Specifies the minimum level of the log. That is, log messages at or above this level. Optional values are 0 (INFO), 1 (WARNING), 2 (ERROR), 3 (FATAL). It is recommended to set it to 0 during debugging and 1 in a production environment. If it is set to 4, NebulaGraph will not print any logs. Yes
v 0 Specifies the detailed level of VLOG. That is, log all VLOG messages less or equal to the level. Optional values are 0, 1, 2, 3, 4, 5. The VLOG macro provided by glog allows users to define their own numeric logging levels and control verbose messages that are logged with the parameter v. For details, see Verbose Logging. Yes
logbufsecs 0 Specifies the maximum time to buffer the logs. If there is a timeout, it will output the buffered log to the log file. 0 means real-time output. This configuration is measured in seconds. No
redirect_stdout true When set to true, the process redirects thestdout and stderr to separate output files. No
stdout_log_file graphd-stdout.log Specifies the filename for the stdout log. No
stderr_log_file graphd-stderr.log Specifies the filename for the stderr log. No
stderrthreshold 3 Specifies the minloglevel to be copied to the stderr log. No
timestamp_in_logfile_name true Specifies if the log file name contains a timestamp. true indicates yes, false indicates no. No

## Query configurations¶

Name Predefined value Description Whether supports runtime dynamic modifications
accept_partial_success false When set to false, the process treats partial success as an error. This configuration only applies to read-only requests. Write requests always treat partial success as an error. Yes
session_reclaim_interval_secs 60 Specifies the interval that the Session information is sent to the Meta service. This configuration is measured in seconds. Yes
max_allowed_query_size 4194304 Specifies the maximum length of queries. Unit: bytes. The default value is 4194304, namely 4MB. Yes

## Networking configurations¶

Name Predefined value Description Whether supports runtime dynamic modifications
meta_server_addrs 127.0.0.1:9559 Specifies the IP addresses and ports of all Meta Services. Multiple addresses are separated with commas. No
local_ip 127.0.0.1 Specifies the local IP for the Graph Service. The local IP address is used to identify the nebula-graphd process. If it is a distributed cluster or requires remote access, modify it to the corresponding address. No
listen_netdev any Specifies the listening network device. No
port 9669 Specifies RPC daemon listening port of the Graph service. No
reuse_port false When set to false, the SO_REUSEPORT is closed. No
listen_backlog 1024 Specifies the maximum length of the connection queue for socket monitoring. This configuration must be modified together with the net.core.somaxconn. No
client_idle_timeout_secs 28800 Specifies the time to expire an idle connection. The value ranges from 1 to 604800. The default is 8 hours. This configuration is measured in seconds. No
session_idle_timeout_secs 28800 Specifies the time to expire an idle session. The value ranges from 1 to 604800. The default is 8 hours. This configuration is measured in seconds. No
num_accept_threads 1 Specifies the number of threads that accept incoming connections. No
num_netio_threads 0 Specifies the number of networking IO threads. 0 is the number of CPU cores. No
num_worker_threads 0 Specifies the number of threads that execute queries. 0 is the number of CPU cores. No
ws_ip 0.0.0.0 Specifies the IP address for the HTTP service. No
ws_http_port 19669 Specifies the port for the HTTP service. No
heartbeat_interval_secs 10 Specifies the default heartbeat interval. Make sure the heartbeat_interval_secs values for all services are the same, otherwise NebulaGraph CANNOT work normally. This configuration is measured in seconds. Yes
storage_client_timeout_ms - Specifies the RPC connection timeout threshold between the Graph Service and the Storage Service. This parameter is not predefined in the initial configuration files. You can manually set it if you need it. The system default value is 60000 ms. No
enable_record_slow_query true Whether to record slow queries.
Only available in NebulaGraph Enterprise Edition.
No
slow_query_limit 100 The maximum number of slow queries that can be recorded.
Only available in NebulaGraph Enterprise Edition.
No
slow_query_threshold_us 200000 When the execution time of a query exceeds the value, the query is called a slow query. Unit: Microsecond. No
ws_meta_http_port 19559 Specifies the Meta service listening port used by the HTTP protocol. It must be consistent with the ws_http_port in the Meta service configuration file. No

Caution

The real IP address must be used in the configuration file. Otherwise, 127.0.0.1/0.0.0.0 cannot be parsed correctly in some cases.

## Charset and collate configurations¶

Name Predefined value Description Whether supports runtime dynamic modifications
default_charset utf8 Specifies the default charset when creating a new graph space. No
default_collate utf8_bin Specifies the default collate when creating a new graph space. No

## Authorization configurations¶

Name Predefined value Description Whether supports runtime dynamic modifications
enable_authorize false When set to false, the system authentication is not enabled. For more information, see Authentication. No
auth_type password Specifies the login method. Available values are password, ldap, and cloud. No

## Memory configurations¶

Name Predefined value Description Whether supports runtime dynamic modifications
system_memory_high_watermark_ratio 0.8 Specifies the trigger threshold of the high-level memory alarm mechanism. If the system memory usage is higher than this value, an alarm mechanism will be triggered, and NebulaGraph will stop querying. This parameter is not predefined in the initial configuration files. Yes

## Audit configurations¶

Enterpriseonly

The audit log is only available in the Enterprise Edition.

## Metrics configurations¶

| Name | Predefined value | Description |Whether supports runtime dynamic modifications| | - | - | - | | enable_space_level_metrics | false | Enable or disable space-level metrics. Such metric names contain the name of the graph space that it monitors, for example, query_latency_us{space=basketballplayer}.avg.3600. You can view the supported metrics with the curl command. For more information, see Query NebulaGraph metrics. | No|

## Session configurations¶

Name Predefined value Description Whether supports runtime dynamic modifications
max_sessions_per_ip_per_user 300 The maximum number of active sessions that can be created from a single IP adddress for a single user. No

## Experimental configurations¶

Name Predefined value Description Whether supports runtime dynamic modifications
enable_experimental_feature false Specifies the experimental feature. Optional values are true and false. No
enable_data_balance true Whether to enable the BALANCE DATA feature. Only works when enable_experimental_feature is true. No

## Black box configurations¶

Enterpriseonly

The Nebula-BBox configurations are for the Enterprise Edition only.

Name Predefined value Description Whether supports runtime dynamic modifications
ng_black_box_switch true Whether to enable the Nebula-BBox feature. No
ng_black_box_home black_box The name of the directory to store Nebula-BBox file data. No
ng_black_box_dump_period_seconds 5 The time interval for Nebula-BBox to collect metric data. Unit: Second. No
ng_black_box_file_lifetime_seconds 1800 Storage time for Nebula-BBox files generated after collecting metric data. Unit: Second. Yes

## Memory tracker configurations¶

Name Predefined value Description Whether supports runtime dynamic modifications
memory_tracker_limit_ratio 0.8 The percentage of free memory. When the free memory is lower than this value, NebulaGraph stops accepting queries.
Calculated as follows:
Free memory / (Total memory - Reserved memory)
Note: For clusters with a mixed-used environment, the value of memory_tracker_limit_ratio should be set to a lower value. For example, when Graphd is expected to occupy only 50% of memory, the value can be set to less than 0.5.
Yes
memory_tracker_untracked_reserved_memory_mb 50 The reserved memory that is not tracked by the memory tracker. Unit: MB. Yes
memory_tracker_detail_log false Whether to enable the memory tracker log. When the value is true, the memory tracker log is generated. Yes
memory_tracker_detail_log_interval_ms 60000 The time interval for generating the memory tracker log. Unit: Millisecond. memory_tracker_detail_log is true when this parameter takes effect. Yes
memory_purge_enabled true Whether to enable the memory purge feature. When the value is true, the memory purge feature is enabled. Yes
memory_purge_interval_seconds 10 The time interval for the memory purge feature to purge memory. Unit: Second. This parameter only takes effect if memory_purge_enabled is set to true. Yes

Last update: March 13, 2023