Parameter configuration

This topic describes FE, BE, and system parameters. It also provides suggestions on how to configure and tune these parameters.

FE configuration items

FE parameters are classified into dynamic parameters and static parameters.

• Dynamic parameters can be configured and adjusted by running SQL commands, which is very convenient. But the configurations become invalid if you restart your FE. Therefore, we recommend that you also modify the configuration items in the fe.conf file to prevent the loss of modifications.

• Static parameters can only be configured and adjusted in the FE configuration file fe.conf. After you modify this file, you must restart your FE for the changes to take effect.

Whether a parameter is a dynamic parameter is indicated by the IsMutable column in the output of ADMIN SHOW CONFIG. TRUE indicates a dynamic parameter.

Note that both dynamic and static FE parameters can be configured in the fe.conf file.

View FE configuration items

After your FE is started, you can run the ADMIN SHOW FRONTEND CONFIG command on your MySQL client to check the parameter configurations. If you want to query the configuration of a specific parameter, run the following command:

 ADMIN SHOW FRONTEND CONFIG [LIKE "pattern"];

For detailed description of the returned fields, see ADMIN SHOW CONFIG.

NOTE

You must have administrator's privilege to run cluster administration-related commands.

Configure FE dynamic parameters

You can configure or modify the settings of FE dynamic parameters using ADMIN SET FRONTEND CONFIG.

ADMIN SET FRONTEND CONFIG ("key" = "value");

NOTE

The configurations will be restored to the default values in the fe.conf file after the FE restarts. Therefore, we recommend that you also modify the configuration items in fe.conf to prevent the loss of modifications.

Logging

Parameter	Unit	Default	Description
qe_slow_log_ms	ms	5000	The threshold used to determine whether a query is a slow query. If the response time of a query exceeds this threshold, it is recorded as a slow query in fe.audit.log.

Metadata and cluster management

Parameter	Unit	Default	Description
catalog_try_lock_timeout_ms	ms	5000	The timeout duration to obtain the global lock.
edit_log_roll_num	-	50000	The maximum number of metadata log entries that can be written before a log file is created for these log entries. This parameter is used to control the size of log files. The new log file is written to the BDBJE database.
ignore_unknown_log_id	-	FALSE	Whether to ignore an unknown log ID. When an FE is rolled back, the BEs of the earlier version may be unable to recognize some log IDs. If the value is TRUE, the FE ignores unknown log IDs. If the value is FALSE, the FE exits.
ignore_materialized_view_error	-	FALSE	Whether FE ignores the metadata exception caused by materialized view errors. If FE fails to start due to the metadata exception caused by materialized view errors, you can set this parameter to true to allow FE to ignore the exception. This parameter is supported from v2.5.10 onwards.
ignore_meta_check	-	FALSE	Whether non-leader FEs ignore the metadata gap from the leader FE. If the value is TRUE, non-leader FEs ignore the metadata gap from the leader FE and continue providing data reading services. This parameter ensures continuous data reading services even when you stop the leader FE for a long period of time. If the value is FALSE, non-leader FEs do not ignore the metadata gap from the leader FE and stop providing data reading services.
meta_delay_toleration_second	s	300	The maximum duration by which the metadata on the follower and observer FEs can lag behind that on the leader FE. Unit: seconds. If this duration is exceeded, the non-leader FE stops providing services.
drop_backend_after_decommission	-	TRUE	Whether to delete a BE after the BE is decommissioned. TRUE indicates that the BE is deleted immediately after it is decommissioned. FALSE indicates that the BE is not deleted after it is decommissioned.
enable_collect_query_detail_info	-	FALSE	Whether to view the profile of a query. If this parameter is set to TRUE, the system collects the profile of the query. If this parameter is set to FALSE, the system does not collect the profile of the query.
enable_background_refresh_connector_metadata	-	true in v3.0 false in v2.5	Whether to enable the periodic Hive metadata cache refresh. After it is enabled, StarRocks polls the metastore (Hive Metastore or AWS Glue) of your Hive cluster, and refreshes the cached metadata of the frequently accessed Hive catalogs to perceive data changes. true indicates to enable the Hive metadata cache refresh, and false indicates to disable it. This parameter is supported from v2.5.5 onwards.
background_refresh_metadata_interval_millis	ms	600000	The interval between two consecutive Hive metadata cache refreshes. This parameter is supported from v2.5.5 onwards.
background_refresh_metadata_time_secs_since_last_access_secs	s	86400	The expiration time of a Hive metadata cache refresh task. For the Hive catalog that has been accessed, if it has not been accessed for more than the specified time, StarRocks stops refreshing its cahced metadata. For the Hive catalog that has not been accessed, StarRocks will not refresh its cached metadata. This parameter is supported from v2.5.5 onwards.

Query engine

Parameter	Unit	Default	Description
max_allowed_in_element_num_of_delete	-	10000	The maximum number of elements allowed for the IN predicate in a DELETE statement.
enable_materialized_view	-	TRUE	Whether to enable the creation of materialized views.
enable_decimal_v3	-	TRUE	Whether to support the DECIMAL V3 data type.
expr_children_limit	-	10000	The maximum number of child expressions allowed in an expression.
enable_sql_blacklist	-	FALSE	Whether to enable blacklist check for SQL queries. When this feature is enabled, queries in the blacklist cannot be executed.
dynamic_partition_check_interval_seconds	s	600	The interval at which new data is checked. If new data is detected, StarRocks automatically creates partitions for the data.
dynamic_partition_enable	-	TRUE	Whether to enable the dynamic partitioning feature. When this feature is enabled, StarRocks dynamically creates partitions for new data and automatically deletes expired partitions to ensure the freshness of data.
max_partitions_in_one_batch	-	4096	The maximum number of partitions that can be created when you bulk create partitions.
max_query_retry_time	-	2	The maximum number of query retries on an FE.
max_create_table_timeout_second	s	600	The maximum timeout duration for creating a table, in seconds.
create_table_max_serial_replicas	-	128	The maximum number of replicas to create serially. If the actual replica count exceeds this, replicas will be created concurrently. Try to reduce this config if table creation takes a long time to complete.
max_running_rollup_job_num_per_table	-	1	The maximum number of rollup jobs can run in parallel for a table.
max_planner_scalar_rewrite_num	-	100000	The maximum number of times that the optimizer can rewrite a scalar operator.
enable_statistic_collect	-	TRUE	Whether to collect statistics for the CBO. This feature is enabled by default.
enable_collect_full_statistic	-	TRUE	Whether to enable automatic full statistics collection. This feature is enabled by default.
statistic_auto_collect_ratio	-	0.8	The threshold for determining whether the statistics for automatic collection are healthy. If statistics health is below this threshold, automatic collection is triggered.
statistic_max_full_collect_data_size	GB	100	The size of the largest partition for automatic collection to collect data. Unit: GB.If a partition exceeds this value, full collection is discarded and sampled collection is performed instead.
statistic_collect_interval_sec	s	300	The interval for checking data updates during automatic collection. Unit: seconds.
statistic_auto_analyze_start_time	STRING	00:00:00	The start time of automatic collection. Value range: 00:00:00 - 23:59:59.
statistic_auto_analyze_end_time	STRING	23:59:59	The end time of automatic collection. Value range: 00:00:00 - 23:59:59.
statistic_sample_collect_rows	-	200000	The minimum number of rows to collect for sampled collection. If the parameter value exceeds the actual number of rows in your table, full collection is performed.
histogram_buckets_size	-	64	The default bucket number for a histogram.
histogram_mcv_size	-	100	The number of most common values (MCV) for a histogram.
histogram_sample_ratio	-	0.1	The sampling ratio for a histogram.
histogram_max_sample_row_count	-	10000000	The maximum number of rows to collect for a histogram.
statistics_manager_sleep_time_sec	s	60	The interval at which metadata is scheduled. Unit: seconds. The system performs the following operations based on this interval: Create tables for storing statistics. Delete statistics that have been deleted. Delete expired statistics.
statistic_update_interval_sec	s	24 * 60 * 60	The interval at which the cache of statistical information is updated. Unit: seconds.
statistic_analyze_status_keep_second	s	259200	The duration to retain the history of collection tasks. The default value is 3 days. Unit: seconds.
statistic_collect_concurrency	-	3	The maximum number of manual collection tasks that can run in parallel. The value defaults to 3, which means you can run a maximum of three manual collection tasks in parallel. If the value is exceeded, incoming tasks will be in the PENDING state, waiting to be scheduled.
enable_local_replica_selection	-	FALSE	Whether to select local replicas for queries. Local replicas reduce the network transmission cost. If this parameter is set to TRUE, the CBO preferentially selects tablet replicas on BEs that have the same IP address as the current FE. If this parameter is set to FALSE, both local replicas and non-local replicas can be selected. The default value is FALSE.
max_distribution_pruner_recursion_depth	-	100	The maximum recursion depth allowed by the partition pruner. Increasing the recursion depth can prune more elements but also increases CPU consumption.
enable_udf	-	FALSE	Whether to enable UDF .

Loading and unloading

Parameter	Unit	Default	Description
max_broker_load_job_concurrency	-	5	The maximum number of concurrent Broker Load jobs allowed within the StarRocks cluster. This parameter is valid only for Broker Load. The value of this parameter must be less than the value of max_running_txn_num_per_db. From v2.5 onwards, the default value is changed from 10 to 5. The alias of this parameter is async_load_task_pool_size.
load_straggler_wait_second	s	300	The maximum loading lag that can be tolerated by a BE replica. If this value is exceeded, cloning is performed to clone data from other replicas. Unit: seconds.
desired_max_waiting_jobs	-	1024	The maximum number of pending jobs in an FE. The number refers to all jobs, such as table creation, loading, and schema change jobs. If the number of pending jobs in an FE reaches this value, the FE will reject new load requests. This parameter takes effect only for asynchronous loading. From v2.5 onwards, the default value is changed from 100 to 1024.
max_load_timeout_second	s	259200	The maximum timeout duration allowed for a load job. The load job fails if this limit is exceeded. This limit applies to all types of load jobs. Unit: seconds.
min_load_timeout_second	s	1	The minimum timeout duration allowed for a load job. This limit applies to all types of load jobs. Unit: seconds.
max_running_txn_num_per_db	-	100	The maximum number of load transactions allowed to be running for each database within a StarRocks cluster. The default value is 100. When the actual number of load transactions running for a database exceeds the value of this parameter, new load requests will not be processed. New requests for synchronous load jobs will be denied, and new requests for asynchronous load jobs will be placed in queue. We do not recommend you increase the value of this parameter because this will increase system load.
load_parallel_instance_num	-	1	The maximum number of concurrent loading instances for each load job on a BE.
disable_load_job	-	FALSE	Whether to disable loading when the cluster encounters an error. This prevents any loss caused by cluster errors. The default value is FALSE, indicating that loading is not disabled. TRUE indicates loading is disabled and the cluster is in read-only state.
history_job_keep_max_second	s	604800	The maximum duration a historical job can be retained, such as schema change jobs, in seconds.
label_keep_max_num	-	1000	The maximum number of load jobs that can be retained within a period of time. If this number is exceeded, the information of historical jobs will be deleted.
label_keep_max_second	s	259200	The maximum duration the labels of load jobs that have been completed and are in the FINISHED or CANCELLED state can be retained in the StarRocks system. The default value is 3 days. After this duration expires, the labels will be deleted. This parameter applies to all types of load jobs. Unit: seconds. A value too large consumes a lot of memory.
max_routine_load_job_num	-	100	The maximum number of Routine Load jobs in a StarRocks cluster.
max_routine_load_task_concurrent_num	-	5	The maximum number of concurrent tasks for each Routine Load job.
max_routine_load_task_num_per_be	-	5	The maximum number of concurrent Routine Load tasks that can run for each BE. The value must be less than or equal to the BE configuration item routine_load_thread_pool_size.
max_routine_load_batch_size	Byte	4294967296	The maximum amount of data that can be loaded by a Routine Load task, in bytes.
routine_load_task_consume_second	s	15	The maximum duration each Routine Load task can consume data, in seconds.
routine_load_task_timeout_second	s	60	The timeout duration for each Routine Load task, in seconds.
routine_load_unstable_threshold_second	s	3600	Routine Load job is set in the UNSTABLE state if any task within the Routine Load job lags. To be specific, the difference between the timestamp of the message being consumed the current time exceeds this threshold. Also, unconsumed messages exist in the data source.
max_tolerable_backend_down_num	-	0	The maximum number of faulty BE nodes allowed. If this number is exceeded, Routine Load jobs cannot be automatically recovered.
period_of_auto_resume_min	Min	5	The interval at which Routine Load jobs are automatically recovered, in minutes.
spark_load_default_timeout_second	s	86400	The timeout duration for each Spark Load job, in seconds.
spark_home_default_dir	-	StarRocksFE.STARROCKS_HOME_DIR + "/lib/spark2x"	The root directory of a Spark client.
stream_load_default_timeout_second	s	600	The default timeout duration for each Stream Load job, in seconds.
max_stream_load_timeout_second	s	259200	The maximum allowed timeout duration for a Stream Load job, in seconds.
insert_load_default_timeout_second	s	3600	The timeout duration for the INSERT INTO statement that is used to load data, in seconds.
broker_load_default_timeout_second	s	14400	The timeout duration for a Broker Load job, in seconds.
min_bytes_per_broker_scanner	Byte	67108864	The minimum allowed amount of data that can be processed by a Broker Load instance, in bytes.
max_broker_concurrency	-	100	The maximum number of concurrent instances for a Broker Load task.
export_max_bytes_per_be_per_task	Byte	268435456	The maximum amount of data that can be exported from a single BE by a single data unload task, in bytes.
export_running_job_num_limit	-	5	The maximum number of data exporting tasks that can run in parallel.
export_task_default_timeout_second	s	7200	The timeout duration for a data exporting task, in seconds.
empty_load_as_error	-	TRUE	Whether to return an error message "all partitions have no load data" if no data is loaded. Values: - TRUE: If no data is loaded, the system displays a failure message and returns an error "all partitions have no load data". - FALSE: If no data is loaded, the system displays a success message and returns OK, instead of an error.
external_table_commit_timeout_ms	ms	10000	The timeout duration for committing (publishing) a write transaction to a StarRocks external table. The default value 10000 indicates a 10-second timeout duration.

Storage

Parameter	Unit	Default	Description
enable_strict_storage_medium_check	-	FALSE	Whether the FE strictly checks the storage medium of BEs when users create tables. If this parameter is set to TRUE, the FE checks the storage medium of BEs when users create tables and returns an error if the storage medium of the BE is different from the storage_medium parameter specified in the CREATE TABLE statement. For example, the storage medium specified in the CREATE TABLE statement is SSD but the actual storage medium of BEs is HDD. As a result, the table creation fails. If this parameter is FALSE, the FE does not check the storage medium of BEs when users create a table.
enable_auto_tablet_distribution	-	TRUE	Whether to automatically set the number of buckets. If this parameter is set to TRUE, you don't need to specify the number of buckets when you create a table or add a partition. StarRocks automatically determines the number of buckets. For the strategy of automatically setting the number of buckets, see Determine the number of buckets. If this parameter is set to FALSE, you need to manually specify the number of buckets when you create a table or add a partition. If you do not specify the bucket count when adding a new partition to a table, the new partition inherits the bucket count set at the creation of the table. However, you can also manually specify the number of buckets for the new partition. Starting from version 2.5.7, StarRocks supports setting this parameter.
storage_usage_soft_limit_percent	%	90	Soft limit of the storage usage percentage in a BE directory. If the storage usage (in percentage) of the BE storage directory exceeds this value and the remaining storage space is less than storage_usage_soft_limit_reserve_bytes, tablets cannot be cloned into this directory.
storage_usage_soft_limit_reserve_bytes	Byte	200 * 1024 * 1024 * 1024	Soft limit of the remaining storage space in a BE directory. If the remaining storage space in the BE storage directory is less than this value and the storage usage (in percentage) exceeds storage_usage_soft_limit_percent, tablets cannot be cloned into this directory.
storage_usage_hard_limit_percent	%	95	Hard limit of the storage usage percentage in a BE directory. If the storage usage (in percentage) of the BE storage directory exceeds this value and the remaining storage space is less than storage_usage_hard_limit_reserve_bytes, Load and Restore jobs are rejected. You need to set this item together with the BE configuration item storage_flood_stage_usage_percent to allow the configurations to take effect.
storage_usage_hard_limit_reserve_bytes	Byte	100 * 1024 * 1024 * 1024	Hard limit of the remaining storage space in a BE directory. If the remaining storage space in the BE storage directory is less than this value and the storage usage (in percentage) exceeds storage_usage_hard_limit_percent, Load and Restore jobs are rejected. You need to set this item together with the BE configuration item storage_flood_stage_left_capacity_bytes to allow the configurations to take effect.
catalog_trash_expire_second	s	86400	The longest duration the metadata can be retained after a table or database is deleted. If this duration expires, the data will be deleted and cannot be recovered. Unit: seconds.
alter_table_timeout_second	s	86400	The timeout duration for the schema change operation (ALTER TABLE). Unit: seconds.
recover_with_empty_tablet	-	FALSE	Whether to replace a lost or corrupted tablet replica with an empty one. If a tablet replica is lost or corrupted, data queries on this tablet or other healthy tablets may fail. Replacing the lost or corrupted tablet replica with an empty tablet ensures that the query can still be executed. However, the result may be incorrect because data is lost. The default value is FALSE, which means lost or corrupted tablet replicas are not replaced with empty ones and the query fails.
tablet_create_timeout_second	s	10	The timeout duration for creating a tablet, in seconds.
tablet_delete_timeout_second	s	2	The timeout duration for deleting a tablet, in seconds.
check_consistency_default_timeout_second	s	600	The timeout duration for a replica consistency check. You can set this parameter based on the size of your tablet.
tablet_sched_slot_num_per_path	-	8	The maximum number of tablet-related tasks that can run concurrently in a BE storage directory. The alias is schedule_slot_num_per_path. From v2.5 onwards, the default value of this parameter is changed from 4 to 8.
tablet_sched_max_scheduling_tablets	-	10000	The maximum number of tablets that can be scheduled at the same time. If the value is exceeded, tablet balancing and repair checks will be skipped.
tablet_sched_disable_balance	-	FALSE	Whether to disable tablet balancing. TRUE indicates that tablet balancing is disabled. FALSE indicates that tablet balancing is enabled. The alias is disable_balance.
tablet_sched_disable_colocate_balance	-	FALSE	Whether to disable replica balancing for Colocate Table. TRUE indicates replica balancing is disabled. FALSE indicates replica balancing is enabled. The alias is disable_colocate_balance.
tablet_sched_max_balancing_tablets	-	500	The maximum number of tablets that can be balanced at the same time. If this value is exceeded, tablet re-balancing will be skipped. The alias is max_balancing_tablets.
tablet_sched_balance_load_disk_safe_threshold	-	0.5	The threshold for determining whether the BE disk usage is balanced. This parameter takes effect only when tablet_sched_balancer_strategy is set to disk_and_tablet. If the disk usage of all BEs is lower than 50%, disk usage is considered balanced. For the disk_and_tablet policy, if the difference between the highest and lowest BE disk usage is greater than 10%, disk usage is considered unbalanced and tablet re-balancing is triggered. The alias is balance_load_disk_safe_threshold.
tablet_sched_balance_load_score_threshold	-	0.1	The threshold for determining whether the BE load is balanced. This parameter takes effect only when tablet_sched_balancer_strategy is set to be_load_score. A BE whose load is 10% lower than the average load is in low load state, and a BE whose load is 10% higher than the average load is in high load state. The alias is balance_load_score_threshold.
tablet_sched_repair_delay_factor_second	s	60	The interval at which replicas are repaired, in seconds. The alias is tablet_repair_delay_factor_second.
tablet_sched_min_clone_task_timeout_sec	s	3 * 60	The minimum timeout duration for cloning a tablet, in seconds.
tablet_sched_max_clone_task_timeout_sec	s	2 * 60 * 60	The maximum timeout duration for cloning a tablet, in seconds. The alias is max_clone_task_timeout_sec.
tablet_sched_max_not_being_scheduled_interval_ms	ms	15 * 60 * 100	When the tablet clone tasks are being scheduled, if a tablet has not been scheduled for the specified time in this parameter, StarRocks gives it a higher priority to schedule it as soon as possible.
tablet_sched_be_down_tolerate_time_s	s	900	The maximum duration the scheduler allows for a BE node to remain inactive. After the time threshold is reached, tablets on that BE node will be migrated to other active BE nodes.

Other FE dynamic parameters

Parameter	Unit	Default	Description
plugin_enable	-	TRUE	Whether plugins can be installed on FEs. Plugins can be installed or uninstalled only on the Leader FE.
max_small_file_number	-	100	The maximum number of small files that can be stored on an FE directory.
max_small_file_size_bytes	Byte	1024 * 1024	The maximum size of a small file, in bytes.
agent_task_resend_wait_time_ms	ms	5000	The duration the FE must wait before it can resend an agent task. An agent task can be resent only when the gap between the task creation time and the current time exceeds the value of this parameter. This parameter is used to prevent repetitive sending of agent tasks. Unit: ms.
backup_job_default_timeout_ms	ms	86400*1000	The timeout duration of a backup job, in ms. If this value is exceeded, the backup job fails.
report_queue_size	-	100	The maximum number of jobs that can wait in a report queue. The report is about disk, task, and tablet information of BEs. If too many report jobs are piling up in a queue, OOM will occur.
enable_experimental_mv	-	TRUE	Whether to enable the asynchronous materialized view feature. TRUE indicates this feature is enabled. From v2.5.2 onwards, this feature is enabled by default. For versions earlier than v2.5.2, this feature is disabled by default.
authentication_ldap_simple_bind_base_dn	-	Empty string	The base DN, which is the point from which the LDAP server starts to search for users' authentication information.
authentication_ldap_simple_bind_root_dn	-	Empty string	The administrator DN used to search for users' authentication information.
authentication_ldap_simple_bind_root_pwd	-	Empty string	The password of the administrator used to search for users' authentication information.
authentication_ldap_simple_server_host	-	Empty string	The host on which the LDAP server runs.
authentication_ldap_simple_server_port	-	389	The port of the LDAP server.
authentication_ldap_simple_user_search_attr	-	uid	The name of the attribute that identifies users in LDAP objects.
max_upload_task_per_be	-	0	In each BACKUP operation, the maximum number of upload tasks StarRocks assigned to a BE node. When this item is set to less than or equal to 0, no limit is imposed on the task number. This item is supported from v2.5.7 onwards.
max_download_task_per_be	-	0	In each RESTORE operation, the maximum number of download tasks StarRocks assigned to a BE node. When this item is set to less than or equal to 0, no limit is imposed on the task number. This item is supported from v2.5.7 onwards.
allow_system_reserved_names	FALSE	Whether to allow users to create columns whose names are initiated with __op and __row. To enable this feature, set this parameter to TRUE. Please note that these name formats are reserved for special purposes in StarRocks and creating such columns may result in undefined behavior. Therefore this feature is disabled by default. This item is supported from v2.5.15 onwards.
default_mv_refresh_immediate	TRUE	Whether to refresh an asynchronous materialized view immediately after creation. When this item is set to true, newly created materialized view will be refreshed immediately. This item is supported from v2.5.18 onwards.

Configure FE static parameters

This section provides an overview of the static parameters that you can configure in the FE configuration file fe.conf. After you reconfigure these parameters for an FE, you must restart the FE for the changes to take effect.

Logging

Parameter	Default	Description
log_roll_size_mb	1024	The size per log file. Unit: MB. The default value 1024 specifies the size per log file as 1 GB.
sys_log_dir	StarRocksFE.STARROCKS_HOME_DIR + "/log"	The directory that stores system log files.
sys_log_level	INFO	The severity levels into which system log entries are classified. Valid values: INFO, WARN, ERROR, and FATAL.
sys_log_verbose_modules	Empty string	The modules for which StarRocks generates system logs. If this parameter is set to org.apache.starrocks.catalog, StarRocks generates system logs only for the catalog module.
sys_log_roll_interval	DAY	The time interval at which StarRocks rotates system log entries. Valid values: DAY and HOUR. If this parameter is set to DAY, a suffix in the yyyyMMdd format is added to the names of system log files. If this parameter is set to HOUR, a suffix in the yyyyMMddHH format is added to the names of system log files.
sys_log_delete_age	7d	The retention period of system log files. The default value 7d specifies that each system log file can be retained for 7 days. StarRocks checks each system log file and deletes those that were generated 7 days ago.
sys_log_roll_num	10	The maximum number of system log files that can be retained within each retention period specified by the sys_log_roll_interval parameter.
audit_log_dir	StarRocksFE.STARROCKS_HOME_DIR + "/log"	The directory that stores audit log files.
audit_log_roll_num	90	The maximum number of audit log files that can be retained within each retention period specified by the audit_log_roll_interval parameter.
audit_log_modules	slow_query, query	The modules for which StarRocks generates audit log entries. By default, StarRocks generates audit logs for the slow_query module and the query module. Separate the module names with a comma (,) and a space.
audit_log_roll_interval	DAY	The time interval at which StarRocks rotates audit log entries. Valid values: DAY and HOUR. If this parameter is set to DAY, a suffix in the yyyyMMdd format is added to the names of audit log files. If this parameter is set to HOUR, a suffix in the yyyyMMddHH format is added to the names of audit log files.
audit_log_delete_age	30d	The retention period of audit log files. The default value 30d specifies that each audit log file can be retained for 30 days. StarRocks checks each audit log file and deletes those that were generated 30 days ago.
dump_log_dir	StarRocksFE.STARROCKS_HOME_DIR + "/log"	The directory that stores dump log files.
dump_log_modules	query	The modules for which StarRocks generates dump log entries. By default, StarRocks generates dump logs for the the query module. Separate the module names with a comma (,) and a space.
dump_log_roll_interval	DAY	The time interval at which StarRocks rotates dump log entries. Valid values: DAY and HOUR. If this parameter is set to DAY, a suffix in the yyyyMMdd format is added to the names of dump log files. If this parameter is set to HOUR, a suffix in the yyyyMMddHH format is added to the names of dump log files.
dump_log_roll_num	10	The maximum number of dump log files that can be retained within each retention period specified by the dump_log_roll_interval parameter.
dump_log_delete_age	7d	The retention period of dump log files. The default value 7d specifies that each dump log file can be retained for 7 days. StarRocks checks each dump log file and deletes those that were generated 7 days ago.

Server

Parameter	Default	Description
frontend_address	0.0.0.0	The IP address of the FE node.
priority_networks	Empty string	Declares a selection strategy for servers that have multiple IP addresses. Note that at most one IP address must match the list specified by this parameter. The value of this parameter is a list that consists of entries, which are separated with semicolons (;) in CIDR notation, such as 10.10.10.0/24. If no IP address matches the entries in this list, an IP address will be randomly selected.
http_port	8030	The port on which the HTTP server in the FE node listens.
http_worker_threads_num	0	Number of worker threads for http server to deal with http requests. For a negative or 0 value, the number of threads will be twice the number of cpu cores. Introduced in: 2.5.18，3.0.10，3.1.7，3.2.2.
http_backlog_num	1024	The length of the backlog queue held by the HTTP server in the FE node.
cluster_name	StarRocks Cluster	The name of the StarRocks cluster to which the FE belongs. The cluster name is displayed for Title on the web page.
rpc_port	9020	The port on which the Thrift server in the FE node listens.
thrift_backlog_num	1024	The length of the backlog queue held by the Thrift server in the FE node.
thrift_server_max_worker_threads	4096	The maximum number of worker threads that are supported by the Thrift server in the FE node.
thrift_client_timeout_ms	5000	The length of time after which idle client connections time out. Unit: ms.
thrift_server_queue_size	4096	The length of queue where requests are pending. If the number of threads that are being processed in the thrift server exceeds the value specified in thrift_server_max_worker_threads, new requests are added to the pending queue.
brpc_idle_wait_max_time	10000	The maximum length of time for which bRPC clients wait as in the idle state. Unit: ms.
query_port	9030	The port on which the MySQL server in the FE node listens.
mysql_service_nio_enabled	TRUE	Specifies whether asynchronous I/O is enabled for the FE node.
mysql_service_io_threads_num	4	The maximum number of threads that can be run by the MySQL server in the FE node to process I/O events.
mysql_nio_backlog_num	1024	The length of the backlog queue held by the MySQL server in the FE node.
max_mysql_service_task_threads_num	4096	The maximum number of threads that can be run by the MySQL server in the FE node to process tasks.
mysql_server_version	5.1.0	The MySQL server version returned to the client. Modifying this parameter will affect the version information in the following situations: 1. select version(); 2. Handshake packet version 3. Value of the global variable version (show variables like 'version';)
max_connection_scheduler_threads_num	4096	The maximum number of threads that are supported by the connection scheduler.
qe_max_connection	1024	The maximum number of connections that can be established by all users to the FE node.
check_java_version	TRUE	Specifies whether to check version compatibility between the executed and compiled Java programs. If the versions are incompatible, StarRocks reports errors and aborts the startup of Java programs.

Metadata and cluster management

Parameter	Default	Description
meta_dir	StarRocksFE.STARROCKS_HOME_DIR + "/meta"	The directory that stores metadata.
heartbeat_mgr_threads_num	8	The number of threads that can be run by the Heartbeat Manager to run heartbeat tasks.
heartbeat_mgr_blocking_queue_size	1024	The size of the blocking queue that stores heartbeat tasks run by the Heartbeat Manager.
metadata_failure_recovery	FALSE	Specifies whether to forcibly reset the metadata of the FE. Exercise caution when you set this parameter.
edit_log_port	9010	The port that is used for communication among the leader, follower, and observer FEs in the StarRocks cluster.
edit_log_type	BDB	The type of edit log that can be generated. Set the value to BDB.
bdbje_heartbeat_timeout_second	30	The amount of time after which the heartbeats among the leader, follower, and observer FEs in the StarRocks cluster time out. Unit: second.
bdbje_lock_timeout_second	1	The amount of time after which a lock in the BDB JE-based FE times out. Unit: second.
max_bdbje_clock_delta_ms	5000	The maximum clock offset that is allowed between the leader FE and the follower or observer FEs in the StarRocks cluster. Unit: ms.
txn_rollback_limit	100	The maximum number of transactions that can be rolled back.
bdbje_replica_ack_timeout_second	10	The maximum amount of time for which the leader FE can wait for ACK messages from a specified number of follower FEs when metadata is written from the leader FE to the follower FEs. Unit: second. If a large amount of metadata is being written, the follower FEs require a long time before they can return ACK messages to the leader FE, causing ACK timeout. In this situation, metadata writes fail, and the FE process exits. We recommend that you increase the value of this parameter to prevent this situation.
master_sync_policy	SYNC	The policy based on which the leader FE flushes logs to disk. This parameter is valid only when the current FE is a leader FE. Valid values: SYNC: When a transaction is committed, a log entry is generated and flushed to disk simultaneously. NO_SYNC: The generation and flushing of a log entry do not occur at the same time when a transaction is committed. WRITE_NO_SYNC: When a transaction is commited, a log entry is generated simultaneously but is not flushed to disk. If you have deployed only one follower FE, we recommend that you set this parameter to SYNC. If you have deployed three or more follower FEs, we recommend that you set this parameter and the replica_sync_policy both to WRITE_NO_SYNC.
replica_sync_policy	SYNC	The policy based on which the follower FE flushes logs to disk. This parameter is valid only when the current FE is a follower FE. Valid values: SYNC: When a transaction is committed, a log entry is generated and flushed to disk simultaneously. NO_SYNC: The generation and flushing of a log entry do not occur at the same time when a transaction is committed. WRITE_NO_SYNC: When a transaction is committed, a log entry is generated simultaneously but is not flushed to disk.
replica_ack_policy	SIMPLE_MAJORITY	The policy based on which a log entry is considered valid. The default value SIMPLE_MAJORITY specifies that a log entry is considered valid if a majority of follower FEs return ACK messages.
cluster_id	-1	The ID of the StarRocks cluster to which the FE belongs. FEs or BEs that have the same cluster ID belong to the same StarRocks cluster. Valid values: any positive integer. The default value -1 specifies that StarRocks will generate a random cluster ID for the StarRocks cluster at the time when the leader FE of the cluster is started for the first time.

Query engine

Parameter	Default	Description
publish_version_interval_ms	10	The time interval at which release validation tasks are issued. Unit: ms.
statistic_cache_columns	100000	The number of rows that can be cached for the statistics table.
statistic_cache_thread_pool_size	10	The size of the thread-pool which will be used to refresh statistic caches.

Loading and unloading

Parameter	Default	Description
async_load_task_pool_size	2	The size of the load task thread pool. This parameter is valid only for Broker Load. The value must be less than max_running_txn_num_per_db. From v2.5 onwards, this parameter is renamed max_broker_load_job_concurrency which is an FE dynamic parameter, and the default value is changed from 10 to 2.
load_checker_interval_second	5	The time interval at which load jobs are processed on a rolling basis. Unit: second.
transaction_clean_interval_second	30	The time interval at which finished transactions are cleaned up. Unit: second. We recommend that you specify a short time interval to ensure that finished transactions can be cleaned up in a timely manner.
label_clean_interval_second	14400	The time interval at which labels are cleaned up. Unit: second. We recommend that you specify a short time interval to ensure that historical labels can be cleaned up in a timely manner.
spark_dpp_version	1.0.0	The version of Spark Dynamic Partition Pruning (DPP) used.
spark_resource_path	Empty string	The root directory of the Spark dependency package.
spark_launcher_log_dir	sys_log_dir + "/spark_launcher_log"	The directory that stores Spark log files.
yarn_client_path	StarRocksFE.STARROCKS_HOME_DIR + "/lib/yarn-client/hadoop/bin/yarn"	The root directory of the Yarn client package.
yarn_config_dir	StarRocksFE.STARROCKS_HOME_DIR + "/lib/yarn-config"	The directory that stores the Yarn configuration file.
export_checker_interval_second	5	The time interval at which load jobs are scheduled.
export_task_pool_size	5	The size of the unload task thread pool.

Storage

Parameter	Default	Description
default_storage_medium	HDD	The default storage media that is used for a table or partition at the time of table or partition creation if no storage media is specified. Valid values: HDD and SSD. When you create a table or partition, the default storage media specified by this parameter is used if you do not specify a storage media type for the table or partition.
tablet_sched_balancer_strategy	disk_and_tablet	The policy based on which load balancing is implemented among tablets. The alias of this parameter is tablet_balancer_strategy. Valid values: disk_and_tablet and be_load_score.
tablet_sched_storage_cooldown_second	-1	The latency of automatic cooling starting from the time of table creation. The alias of this parameter is storage_cooldown_second. Unit: second. The default value -1 specifies that automatic cooling is disabled. If you want to enable automatic cooling, set this parameter to a value greater than -1.
tablet_stat_update_interval_second	300	The time interval at which the FE retrieves tablet statistics from each BE. Unit: second.

Other FE static parameters

Parameter	Default	Description
plugin_dir	STARROCKS_HOME_DIR/plugins	The directory that stores plugin installation packages.
small_file_dir	StarRocksFE.STARROCKS_HOME_DIR + "/small_files"	The root directory of small files.
max_agent_task_threads_num	4096	The maximum number of threads that are allowed in the agent task thread pool.
auth_token	Empty string	The token that is used for identity authentication within the StarRocks cluster to which the FE belongs. If this parameter is left unspecified, StarRocks generates a random token for the cluster at the time when the leader FE of the cluster is started for the first time.
tmp_dir	StarRocksFE.STARROCKS_HOME_DIR + "/temp_dir"	The directory that stores temporary files such as files generated during backup and restore procedures. After these procedures finish, the generated temporary files are deleted.
locale	zh_CN.UTF-8	The character set that is used by the FE.
hive_meta_load_concurrency	4	The maximum number of concurrent threads that are supported for Hive metadata.
hive_meta_cache_refresh_interval_s	7200	The time interval at which the cached metadata of Hive external tables is updated. Unit: second.
hive_meta_cache_ttl_s	86400	The amount of time after which the cached metadata of Hive external tables expires. Unit: second.
hive_meta_store_timeout_s	10	The amount of time after which a connection to a Hive metastore times out. Unit: second.
es_state_sync_interval_second	10	The time interval at which the FE obtains Elasticsearch indexes and synchronizes the metadata of StarRocks external tables. Unit: second.
enable_auth_check	TRUE	Specifies whether to enable the authentication check feature. Valid values: TRUE and FALSE. TRUE specifies to enable this feature, and FALSE specifies to disable this feature.
enable_metric_calculator	TRUE	Specifies whether to enable the feature that is used to periodically collect metrics. Valid values: TRUE and FALSE. TRUE specifies to enable this feature, and FALSE specifies to disable this feature.

BE configuration items

Some BE configuration items are dynamic parameters which you can set them by commands when BE nodes are still online. The rest of them are static parameters. You can only set the static parameters of a BE node by changing them in the corresponding configuration file be.conf, and restart the BE node to allow the change to take effect.

View BE configuration items

You can view the BE configuration items using the following command:

curl http://<BE_IP>:<BE_HTTP_PORT>/varz

Configure BE dynamic parameters

You can configure a dynamic parameter of a BE node by using the curl command.

curl -XPOST http://be_host:http_port/api/update_config?<configuration_item>=<value>

BE dynamic parameters are as follows.

Configuration item	Default	Unit	Description
enable_stream_load_verbose_log	false	N/A	Specifies whether to log the HTTP requests and responses for Stream Load jobs. This parameter is introduced in 2.5.17, 3.0.9, 3.1.6, and 3.2.1.
report_task_interval_seconds	10	Second	The time interval at which to report the state of a task. A task can be creating a table, dropping a table, loading data, or changing a table schema.
report_disk_state_interval_seconds	60	Second	The time interval at which to report the storage volume state, which includes the size of data within the volume.
report_tablet_interval_seconds	60	Second	The time interval at which to report the most updated version of all tablets.
report_workgroup_interval_seconds	5	Second	The time interval at which to report the most updated version of all workgroups.
max_download_speed_kbps	50000	KB/s	The maximum download speed of each HTTP request. This value affects the performance of data replica synchronization across BE nodes.
download_low_speed_limit_kbps	50	KB/s	The download speed lower limit of each HTTP request. An HTTP request aborts when it constantly runs with a lower speed than this value within the time span specified in the configuration item download_low_speed_time.
download_low_speed_time	300	Second	The maximum time that an HTTP request can run with a download speed lower than the limit. An HTTP request aborts when it constantly runs with a lower speed than the value of download_low_speed_limit_kbps within the time span specified in this configuration item.
status_report_interval	5	Second	The time interval at which a query reports its profile, which can be used for query statistics collection by FE.
scanner_thread_pool_thread_num	48	N/A	The number of threads which the storage engine used for concurrent storage volume scanning. All threads are managed in the thread pool.
thrift_client_retry_interval_ms	100	ms	The time interval at which a thrift client retries.
scanner_thread_pool_queue_size	102400	N/A	The number of scan tasks supported by the storage engine.
scanner_row_num	16384	N/A	The maximum row count returned by each scan thread in a scan.
max_scan_key_num	1024	N/A	The maximum number of scan key segmented by each query.
max_pushdown_conditions_per_column	1024	N/A	The maximum number of conditions that allow pushdown in each column. If the number of conditions exceeds this limit, the predicates are not pushed down to the storage layer.
exchg_node_buffer_size_bytes	10485760	Byte	The maximum buffer size on the receiver end of an exchange node for each query. This configuration item is a soft limit. A backpressure is triggered when data is sent to the receiver end with an excessive speed.
memory_limitation_per_thread_for_schema_change	2	GB	The maximum memory size allowed for each schema change task.
update_cache_expire_sec	360	Second	The expiration time of Update Cache.
file_descriptor_cache_clean_interval	3600	Second	The time interval at which to clean file descriptors that have not been used for a certain period of time.
disk_stat_monitor_interval	5	Second	The time interval at which to monitor health status of disks.
unused_rowset_monitor_interval	30	Second	The time interval at which to clean the expired rowsets.
max_percentage_of_error_disk	0	%	The maximum percentage of error that is tolerable in a storage volume before the corresponding BE node quits.
default_num_rows_per_column_file_block	1024	N/A	The maximum number of rows that can be stored in each row block.
pending_data_expire_time_sec	1800	Second	The expiration time of the pending data in the storage engine.
inc_rowset_expired_sec	1800	Second	The expiration time of the incoming data. This configuration item is used in incremental clone.
tablet_rowset_stale_sweep_time_sec	1800	Second	The time interval at which to sweep the stale rowsets in tablets. A shorter interval can reduce metadata usage during loading.
snapshot_expire_time_sec	172800	Second	The expiration time of snapshot files.
trash_file_expire_time_sec	86,400	Second	The time interval at which to clean trash files. The default value has been changed from 259,200 to 86,400 since v2.5.17, v3.0.9, and v3.1.6.
base_compaction_check_interval_seconds	60	Second	The time interval of thread polling for a Base Compaction.
min_base_compaction_num_singleton_deltas	5	N/A	The minimum number of segments that trigger a Base Compaction.
max_base_compaction_num_singleton_deltas	100	N/A	The maximum number of segments that can be compacted in each Base Compaction.
base_compaction_interval_seconds_since_last_operation	86400	Second	The time interval since the last Base Compaction. This configuration item is one of the conditions that trigger a Base Compaction.
cumulative_compaction_check_interval_seconds	1	Second	The time interval of thread polling for a Cumulative Compaction.
update_compaction_check_interval_seconds	60	Second	The time interval at which to check the Update Compaction of the Primary Key table.
min_compaction_failure_interval_sec	120	Second	The minimum time interval that a Tablet Compaction can be scheduled since the last compaction failure.
max_compaction_concurrency	-1	N/A	The maximum concurrency of compactions (both Base Compaction and Cumulative Compaction). The value -1 indicates that no limit is imposed on the concurrency.
periodic_counter_update_period_ms	500	ms	The time interval at which to collect the Counter statistics.
pindex_major_compaction_limit_per_disk	1	N/A	The maximum concurrency of compaction on a disk. This addresses the issue of uneven I/O across disks due to compaction. This issue can cause excessively high I/O for certain disks. Introduced in: 3.0.9
load_error_log_reserve_hours	48	Hour	The time for which data loading logs are reserved.
streaming_load_max_mb	10240	MB	The maximum size of a file that can be streamed into StarRocks.
streaming_load_max_batch_size_mb	100	MB	The maximum size of a JSON file that can be streamed into StarRocks.
memory_maintenance_sleep_time_s	10	Second	The time interval at which ColumnPool GC is triggered. StarRocks executes GC periodically, and returns the released memory memory to the operating system.
write_buffer_size	104857600	Byte	The buffer size of MemTable in the memory. This configuration item is the threshold to trigger a flush.
tablet_stat_cache_update_interval_second	300	Second	The time interval at which to update Tablet Stat Cache.
result_buffer_cancelled_interval_time	300	Second	The wait time before BufferControlBlock release data.
thrift_rpc_timeout_ms	5000	ms	The timeout for a thrift RPC.
txn_commit_rpc_timeout_ms	20000	ms	The timeout for a transaction commit RPC.
max_consumer_num_per_group	3	N/A	The maximum number of consumers in a consumer group of Routine Load.
max_memory_sink_batch_count	20	N/A	The maximum number of Scan Cache batches.
scan_context_gc_interval_min	5	Minute	The time interval at which to clean the Scan Context.
path_gc_check_step	1000	N/A	The maximum number of files that can be scanned continuously each time.
path_gc_check_step_interval_ms	10	ms	The time interval between file scans.
path_scan_interval_second	86400	Second	The time interval at which GC cleans expired data.
storage_flood_stage_usage_percent	95	%	Hard limit of the storage usage percentage in all BE directories. If the storage usage (in percentage) of the BE storage directory exceeds this value and the remaining storage space is less than storage_flood_stage_left_capacity_bytes, Load and Restore jobs are rejected. You need to set this item together with the FE configuration item storage_usage_hard_limit_percent to allow the configurations to take effect.
storage_flood_stage_left_capacity_bytes	107374182400	Byte	Hard limit of the remaining storage space in all BE directories. If the remaining storage space of the BE storage directory is less than this value and the storage usage (in percentage) exceeds storage_flood_stage_usage_percent, Load and Restore jobs are rejected. You need to set this item together with the FE configuration item storage_usage_hard_limit_reserve_bytes to allow the configurations to take effect.
tablet_meta_checkpoint_min_new_rowsets_num	10	N/A	The minimum number of rowsets to create since the last TabletMeta Checkpoint.
tablet_meta_checkpoint_min_interval_secs	600	Second	The time interval of thread polling for a TabletMeta Checkpoint.
max_runnings_transactions_per_txn_map	100	N/A	The maximum number of transactions that can run concurrently in each partition.
tablet_max_pending_versions	1000	N/A	The maximum number of pending versions that are tolerable on a Primary Key tablet. Pending versions refer to versions that are committed but not applied yet.
tablet_max_versions	1000	N/A	The maximum number of versions allowed on a tablet. If the number of versions exceeds this value, new write requests will fail.
max_hdfs_file_handle	1000	N/A	The maximum number of HDFS file descriptors that can be opened.
parquet_buffer_stream_reserve_size	1048576	Byte	The size of buffer that Parquet reader reserves for each column while reading data.
be_exit_after_disk_write_hang_second	60	second	The length of time that the BE waits to exit after the disk hangs.
min_cumulative_compaction_failure_interval_sec	30	second	The minimum time interval at which Cumulative Compaction retries upon failures.
size_tiered_level_num	7	N/A	The number of levels for the Size-tiered Compaction strategy. At most one rowset is reserved for each level. Therefore, under a stable condition, there are, at most, as many rowsets as the level number specified in this configuration item.
size_tiered_level_multiple	5	N/A	The multiple of data size between two contiguous levels in the Size-tiered Compaction strategy.
size_tiered_min_level_size	131072	Byte	The data size of the minimum level in the Size-tiered Compaction strategy. Rowsets smaller than this value immediately trigger the data compaction.
storage_page_cache_limit	20%	N/A	The PageCache size. STRING. It can be specified as size, for example, 20G, 20480M, 20971520K, or 21474836480B. It can also be specified as the ratio (percentage) to the memory size, for example, 20%. It takes effect only when disable_storage_page_cache is set to false.

Configure BE static parameters

You can only set the static parameters of a BE by changing them in the corresponding configuration file be.conf, and restart the BE to allow the changes to take effect.

BE static parameters are as follows.

be_port

• Default: 9060
• Unit: N/A
• Description: The BE thrift server port, which is used to receive requests from FEs.

brpc_port

• Default: 8060
• Unit: N/A
• Description: The BE bRPC port, which is used to view the network statistics of bRPCs.

brpc_num_threads

• Default: -1
• Unit: N/A
• Description: The number of bthreads of a bRPC. The value -1 indicates the same number with the CPU threads.

priority_networks

• Default: Empty string
• Unit: N/A
• Description: The CIDR-formatted IP address that is used to specify the priority IP address of a BE node if the machine that hosts the BE node has multiple IP addresses.

heartbeat_service_port

• Default: 9050
• Unit: N/A
• Description: The BE heartbeat service port, which is used to receive heartbeats from FEs.

heartbeat_service_thread_count

• Default: 1
• Unit: N/A
• Description: The thread count of the BE heartbeat service.

create_tablet_worker_count

• Default: 3
• Unit: N/A
• Description: The number of threads used to create a tablet.

drop_tablet_worker_count

• Default: 3
• Unit: N/A
• Description: The number of threads used to drop a tablet.

push_worker_count_normal_priority

• Default: 3
• Unit: N/A
• Description: The number of threads used to handle a load task with NORMAL priority.

push_worker_count_high_priority

• Default: 3
• Unit: N/A
• Description: The number of threads used to handle a load task with HIGH priority.

transaction_publish_version_worker_count

• Default: 0
• Unit: N/A
• Description: The maximum number of threads used to publish a version. When this value is set to less than or equal to 0, the system uses half of the CPU core count as the value, so as to avoid insufficient thread resources when import concurrency is high but only a fixed number of threads are used. From v2.5, the default value has been changed from 8 to 0.

clear_transaction_task_worker_count

• Default: 1
• Unit: N/A
• Description: The number of threads used for clearing transaction.

alter_tablet_worker_count

• Default: 3
• Unit: N/A
• Description: The number of threads used for schema change.

clone_worker_count

• Default: 3
• Unit: N/A
• Description: The number of threads used for clone.

storage_medium_migrate_count

• Default: 1
• Unit: N/A
• Description: The number of threads used for storage medium migration (from SATA to SSD).

check_consistency_worker_count

• Default: 1
• Unit: N/A
• Description: The number of threads used for checking the consistency of tablets.

sys_log_dir

• Default: ${STARROCKS_HOME}/log
• Unit: N/A
• Description: The directory that stores system logs (including INFO, WARNING, ERROR, and FATAL).

user_function_dir

• Default: ${STARROCKS_HOME}/lib/udf
• Unit: N/A
• Description: The directory used to store User-defined Functions (UDFs).

small_file_dir

• Default: ${STARROCKS_HOME}/lib/small_file
• Unit: N/A
• Description: The directory used to store the files downloaded by the file manager.

sys_log_level

• Default: INFO
• Unit: N/A
• Description: The severity levels into which system log entries are classified. Valid values: INFO, WARN, ERROR, and FATAL.

sys_log_roll_mode

• Default: SIZE-MB-1024
• Unit: N/A
• Description: The mode in which system logs are segmented into log rolls. Valid values include TIME-DAY, TIME-HOUR, and SIZE-MB-size. The default value indicates that logs are segmented into rolls, each of which is 1 GB.

sys_log_roll_num

• Default: 10
• Unit: N/A
• Description: The number of log rolls to reserve.

sys_log_verbose_modules

• Default: Empty string
• Unit: N/A
• Description: The module of the logs to be printed. For example, if you set this configuration item to OLAP, StarRocks only prints the logs of the OLAP module. Valid values are namespaces in BE, including starrocks, starrocks::vectorized, and pipeline

sys_log_verbose_level

• Default: 10
• Unit: N/A
• Description: The level of the logs to be printed. This configuration item is used to control the output of logs initiated with VLOG in codes.

log_buffer_level

• Default: Empty string
• Unit: N/A
• Description: The strategy for flushing logs. The default value indicates that logs are buffered in memory. Valid values are -1 and 0. -1 indicates that logs are not buffered in memory.

num_threads_per_core

• Default: 3
• Unit: N/A
• Description: The number of threads started on each CPU core.

compress_rowbatches

• Default: TRUE
• Unit: N/A
• Description: A boolean value to control whether to compress the row batches in RPCs between BEs. TRUE indicates compressing the row batches, and FALSE indicates not compressing them.

serialize_batch

• Default: FALSE
• Unit: N/A
• Description: A boolean value to control whether to serialize the row batches in RPCs between BEs. TRUE indicates serializing the row batches, and FALSE indicates not serializing them.

storage_root_path

• Default: ${STARROCKS_HOME}/storage
• Unit: N/A
• Description: The directory and medium of the storage volume.
  • Multiple volumes are separated by semicolons (;).
  • If the storage medium is SSD, add medium:ssd at the end of the directory.
  • If the storage medium is HDD, add medium:hdd at the end of the directory.

max_tablet_num_per_shard

• Default: 1024
• Unit: N/A
• Description: The maximum number of tablets in each shard. This configuration item is used to restrict the number of tablet child directories under each storage directory.

max_garbage_sweep_interval

• Default: 3600
• Unit: Second
• Description: The maximum time interval for garbage collection on storage volumes.

min_garbage_sweep_interval

• Default: 180
• Unit: Second
• Description: The minimum time interval for garbage collection on storage volumes.

row_nums_check

• Default: True
• Unit: N/A
• Description: A boolean value to control whether to check row counts before and after compaction. The value true indicates to enable the row count check. The value false indicates disable the row count check.

file_descriptor_cache_capacity

• Default: 16384
• Unit: N/A
• Description: The number of file descriptors that can be cached.

min_file_descriptor_number

• Default: 60000
• Unit: N/A
• Description: The minimum number of file descriptors in the BE process.

index_stream_cache_capacity

• Default: 10737418240
• Unit: Byte
• Description: The cache capacity for the statistical information of BloomFilter, Min, and Max.

disable_storage_page_cache

• Default: FALSE
• Unit: N/A
• Description: A boolean value to control whether to disable PageCache.
  • When PageCache is enabled, StarRocks caches the recently scanned data.
  • PageCache can significantly improve the query performance when similar queries are repeated frequently.
  • TRUE indicates disabling PageCache.
  • The default value of this item has been changed from TRUE to FALSE since StarRocks v2.4.

base_compaction_num_threads_per_disk

• Default: 1
• Unit: N/A
• Description: The number of threads used for Base Compaction on each storage volume.

base_cumulative_delta_ratio

• Default: 0.3
• Unit: N/A
• Description: The ratio of cumulative file size to base file size. The ratio reaching this value is one of the conditions that triggers Base Compaction.

compaction_trace_threshold

• Default: 60
• Unit: Second
• Description: The time threshold for each compaction. If a compaction takes more time than the time threshold, StarRocks prints the corresponding trace.

webserver_port

• Default: 8040
• Unit: N/A
• Description: The HTTP server port.

webserver_num_workers

• Default: 48
• Unit: N/A
• Description: The number of thread used by the HTTP server.

load_data_reserve_hours

• Default: 4
• Unit: Hour
• Description: The reservation time for the files produced by small-scale loadings.

number_tablet_writer_threads

• Default: 16
• Unit: N/A
• Description: The number of threads used for Stream Load.

streaming_load_rpc_max_alive_time_sec

• Default: 1200
• Unit: Second
• Description: The RPC timeout for Stream Load.

fragment_pool_thread_num_min

• Default: 64
• Unit: N/A
• Description: The minimum number of threads used for query.

fragment_pool_thread_num_max

• Default: 4096
• Unit: N/A
• Description: The maximum number of threads used for query.

fragment_pool_queue_size

• Default: 2048
• Unit: N/A
• Description: The upper limit of the number of queries that can be processed on each BE node.

enable_partitioned_aggregation

• Default: TRUE
• Unit: N/A
• Description: A boolean value to control whether to enable Partition Aggregation. The value true indicates to enable the Partition Aggregation. The value false indicates to disable the Partition Aggregation. |

enable_token_check

• Default: TRUE
• Unit: N/A
• Description: A boolean value to control whether to enable the token check. TRUE indicates enabling the token check, and FALSE indicates disabling it.

enable_prefetch

• Default: TRUE
• Unit: N/A
• Description: A boolean value to control whether to enable the pre-fetch of the query. TRUE indicates enabling pre-fetch, and FALSE indicates disabling it.

load_process_max_memory_limit_bytes

• Default: 107374182400
• Unit: Byte
• Description: The maximum size limit of memory resources that can be taken up by all load processes on a BE node.

load_process_max_memory_limit_percent

• Default: 30
• Unit: %
• Description: The maximum percentage limit of memory resources that can be taken up by all load processes on a BE node.

sync_tablet_meta

• Default: FALSE
• Unit: N/A
• Description: A boolean value to control whether to enable the synchronization of the tablet metadata. TRUE indicates enabling synchronization, and FALSE indicates disabling it.

routine_load_thread_pool_size

• Default: 10
• Unit: N/A
• Description: The thread pool size for Routine Load on each BE.

internal_service_async_thread_num

• Default: 10 (Number of Threads)
• Description: The thread pool size allowed on each BE for interacting with Kafka. Currently, the FE responsible for processing Routine Load requests depends on BEs to interact with Kafka, and each BE in StarRocks has its own thread pool for interactions with Kafka. If a large number of Routine Load tasks are distributed to a BE, the BE's thread pool for interactions with Kafka may be too busy to process all tasks in a timely manner. In this situation, you can adjust the value of this parameter to suit your needs.

brpc_max_body_size

• Default: 2147483648
• Unit: Byte
• Description: The maximum body size of a bRPC.

tablet_map_shard_size

• Default: 32
• Unit: N/A
• Description: The tablet map shard size. The value must be a power of two.

enable_bitmap_union_disk_format_with_set

• Default: FALSE
• Unit: N/A
• Description: A boolean value to control whether to enable the new storage format of the BITMAP type, which can improve the performance of bitmap_union. TRUE indicates enabling the new storage format, and FALSE indicates disabling it.

mem_limit

• Default: 90%
• Unit: N/A
• Description: BE process memory upper limit. You can set it as a percentage ("80%") or a physical limit ("100G"). The default hard limit is 90% of the server's memory size, and the soft limit is 80%. You need to configure this parameter if you want to deploy StarRocks with other memory-intensive services on a same server.

flush_thread_num_per_store

• Default: 2
• Unit: N/A
• Description: Number of threads that are used for flushing MemTable in each store.

block_cache_enable

• Default: false
• Unit: N/A
• Description: Whether to enable Data Cache. TRUE indicates Data Cache is enabled, and FALSE indicates Data Cache is disabled.

block_cache_disk_path

• Default: N/A
• Unit: N/A
• Description: The paths of disks. We recommend that the number of paths you configure for this parameter is the same as the number of disks on your BE machine. Multiple paths need to be separated with semicolons (;). After you add this parameter, StarRocks automatically creates a file named cachelib_data to cache blocks.

block_cache_meta_path

• Default: N/A
• Unit: N/A
• Description: The storage path of block metadata. You can customize the storage path. We recommend that you store the metadata under the $STARROCKS_HOME path.

block_cache_mem_size

• Default: 2147483648
• Unit: Bytes
• Description: The maximum amount of data that can be cached in memory. Unit: bytes. The default value is 2147483648, which is 2 GB. We recommend that you set the value of this parameter to at least 20 GB. If StarRocks reads a large amount of data from disks after Data Cache is enabled, consider increasing the value.

block_cache_disk_size

• Default: 0
• Unit: Bytes
• Description: The maximum amount of data that can be cached on a single disk. For example, if you configure two disk paths for the block_cache_disk_path parameter and set the value of the block_cache_disk_size parameter as 21474836480 (20 GB), a maximum of 40 GB data can be cached on these two disks. The default value is 0, which indicates that only memory is used to cache data. Unit: bytes.

jdbc_connection_pool_size

• Default: 8
• Unit: N/A
• Description: The JDBC connection pool size. On each BE node, queries that access the external table with the same jdbc_url share the same connection pool.

jdbc_minimum_idle_connections

• Default: 1
• Unit: N/A
• Description: The minimum number of idle connections in the JDBC connection pool.

jdbc_connection_idle_timeout_ms

• Default: 600000
• Unit: N/A
• Description: The length of time after which an idle connection in the JDBC connection pool expires. If the connection idle time in the JDBC connection pool exceeds this value, the connection pool closes idle connections beyond the number specified in the configuration item jdbc_minimum_idle_connections.

query_cache_capacity

• Default: 536870912
• Unit: N/A
• Description: The size of the query cache in the BE. Unit: bytes. The default size is 512 MB. The size cannot be less than 4 MB. If the memory capacity of the BE is insufficient to provision your expected query cache size, you can increase the memory capacity of the BE.

enable_event_based_compaction_framework

• Default: TRUE
• Unit: N/A
• Description: Whether to enable the Event-based Compaction Framework. TRUE indicates Event-based Compaction Framework is enabled, and FALSE indicates it is disabled. Enabling Event-based Compaction Framework can greatly reduce the overhead of compaction in scenarios where there are many tablets or a single tablet has a large amount of data.

enable_size_tiered_compaction_strategy

• Default: TRUE
• Unit: N/A
• Description: Whether to enable the Size-tiered Compaction strategy. TRUE indicates the Size-tiered Compaction strategy is enabled, and FALSE indicates it is disabled.

update_compaction_size_threshold

• Default: 67108864
• Unit: bytes
• Description: The Compaction Score of Primary Key tables is calculated based on the file size, which is different from other table types. This parameter can be used to make the Compaction Score of Primary Key tables similar to that of other table types, making it easier for users to understand. Since v2.5.20, the default value of this parameter is changed from 268435456 (256 MB) to 67108864 (64 MB) to accelerate compaction.