FE Configuration

This document mainly introduces the relevant configuration items of FE.

The FE configuration file fe.conf is usually stored in the conf/ directory of the FE deployment path. In version 0.14, another configuration file fe_custom.conf will be introduced. The configuration file is used to record the configuration items that are dynamically configured and persisted by the user during operation.

After the FE process is started, it will read the configuration items in fe.conf first, and then read the configuration items in fe_custom.conf. The configuration items in fe_custom.conf will overwrite the same configuration items in fe.conf.

The location of the fe_custom.conf file can be configured in fe.conf through the custom_config_dir configuration item.

View configuration items

There are two ways to view the configuration items of FE:

  1. FE web page

    Open the FE web page http://fe_host:fe_http_port/variable in the browser. You can see the currently effective FE configuration items in Configure Info.

  2. View by command

    After the FE is started, you can view the configuration items of the FE in the MySQL client with the following command:

    ADMIN SHOW FRONTEND CONFIG;

    The meanings of the columns in the results are as follows:

    • Key: the name of the configuration item.
    • Value: The value of the current configuration item.
    • Type: The configuration item value type, such as integer or string.
    • IsMutable: whether it can be dynamically configured. If true, the configuration item can be dynamically configured at runtime. If false, it means that the configuration item can only be configured in fe.conf and takes effect after restarting FE.
    • MasterOnly: Whether it is a unique configuration item of Master FE node. If it is true, it means that the configuration item is meaningful only at the Master FE node, and is meaningless to other types of FE nodes. If false, it means that the configuration item is meaningful in all types of FE nodes.
    • Comment: The description of the configuration item.

Set configuration items

There are two ways to configure FE configuration items:

  1. Static configuration

    Add and set configuration items in the conf/fe.conf file. The configuration items in fe.conf will be read when the FE process starts. Configuration items not in fe.conf will use default values.

  2. Dynamic configuration via MySQL protocol

    After the FE starts, you can set the configuration items dynamically through the following commands. This command requires administrator privilege.

    ADMIN SET FRONTEND CONFIG (" fe_config_name "=" fe_config_value ");

    Not all configuration items support dynamic configuration. You can check whether the dynamic configuration is supported by the IsMutable column in theADMIN SHOW FRONTEND CONFIG;command result.

    If the configuration item of MasterOnly is modified, the command will be directly forwarded to the Master FE and only the corresponding configuration item in the Master FE will be modified.

    Configuration items modified in this way will become invalid after the FE process restarts.

    For more help on this command, you can view it through the HELP ADMIN SET CONFIG; command.

  3. Dynamic configuration via HTTP protocol

    For details, please refer to Set Config Action

    This method can also persist the modified configuration items. The configuration items will be persisted in the fe_custom.conf file and will still take effect after FE is restarted.

Examples

  1. Modify async_pending_load_task_pool_size

    Through ADMIN SHOW FRONTEND CONFIG; you can see that this configuration item cannot be dynamically configured (IsMutable is false). You need to add in fe.conf:

    async_pending_load_task_pool_size = 20

    Then restart the FE process to take effect the configuration.

  2. Modify dynamic_partition_enable

    Through ADMIN SHOW FRONTEND CONFIG; you can see that the configuration item can be dynamically configured (IsMutable is true). And it is the unique configuration of Master FE. Then first we can connect to any FE and execute the following command to modify the configuration:

    1. ADMIN SET FRONTEND CONFIG ("dynamic_partition_enable" = "true"); `

    Afterwards, you can view the modified value with the following command:

    1. set forward_to_master = true;
    2. ADMIN SHOW FRONTEND CONFIG;

    After modification in the above manner, if the Master FE restarts or a Master election is performed, the configuration will be invalid. You can add the configuration item directly in fe.conf and restart the FE to make the configuration item permanent.

  3. Modify max_distribution_pruner_recursion_depth

    Through ADMIN SHOW FRONTEND CONFIG; you can see that the configuration item can be dynamically configured (IsMutable is true). It is not unique to Master FE.

    Similarly, we can modify the configuration by dynamically modifying the configuration command. Because this configuration is not unique to the Master FE, user need to connect to different FEs separately to modify the configuration dynamically, so that all FEs use the modified configuration values.

Configurations

agent_task_resend_wait_time_ms

This configuration will decide whether to resend agent task when create_time for agent_task is set, only when current_time - create_time > agent_task_resend_wait_time_ms can ReportHandler do resend agent task.

This configuration is currently mainly used to solve the problem of repeated sending of PUBLISH_VERSION agent tasks. The current default value of this configuration is 5000, which is an experimental value.

Because there is a certain time delay between submitting agent tasks to AgentTaskQueue and submitting to be, Increasing the value of this configuration can effectively solve the problem of repeated sending of agent tasks,

But at the same time, it will cause the submission of failed or failed execution of the agent task to be executed again for an extended period of time.

alter_table_timeout_second

async_load_task_pool_size

This configuration is just for compatible with old version, this config has been replaced by async_loading_load_task_pool_size, it will be removed in the future.

async_loading_load_task_pool_size

The loading_load task executor pool size. This pool size limits the max running loading_load tasks.

Currently, it only limits the loading_load task of broker load.

async_pending_load_task_pool_size

The pending_load task executor pool size. This pool size limits the max running pending_load tasks.

Currently, it only limits the pending_load task of broker load and spark load.

It should be less than ‘max_running_txn_num_per_db’

audit_log_delete_age

audit_log_dir

audit_log_modules

audit_log_roll_interval

audit_log_roll_mode

audit_log_roll_num

auth_token

autocommit

auto_increment_increment

backup_job_default_timeout_ms

backup_plugin_path

balance_load_score_threshold

batch_size

bdbje_heartbeat_timeout_second

bdbje_lock_timeout_second

broker_load_default_timeout_second

brpc_idle_wait_max_time

brpc_number_of_concurrent_requests_processed

capacity_used_percent_high_water

catalog_trash_expire_second

catalog_try_lock_timeout_ms

character_set_client

character_set_connection

character_set_results

character_set_server

check_consistency_default_timeout_second

check_java_version

clone_capacity_balance_threshold

clone_checker_interval_second

clone_distribution_balance_threshold

clone_high_priority_delay_second

clone_job_timeout_second

clone_low_priority_delay_second

clone_max_job_num

clone_normal_priority_delay_second

cluster_id

cluster_name

codegen_level

collation_connection

collation_database

collation_server

consistency_check_end_time

consistency_check_start_time

custom_config_dir

Configure the location of the fe_custom.conf file. The default is in the conf/ directory.

In some deployment environments, the conf/ directory may be overwritten due to system upgrades. This will cause the user modified configuration items to be overwritten. At this time, we can store fe_custom.conf in another specified directory to prevent the configuration file from being overwritten.

db_used_data_quota_update_interval_secs

For better data load performance, in the check of whether the amount of data used by the database before data load exceeds the quota, we do not calculate the amount of data already used by the database in real time, but obtain the periodically updated value of the daemon thread.

This configuration is used to set the time interval for updating the value of the amount of data used by the database.

default_rowset_type

default_storage_medium

delete_thread_num

desired_max_waiting_jobs

disable_balance

disable_cluster_feature

disable_colocate_balance

disable_colocate_join

disable_colocate_join

disable_colocate_relocate

disable_hadoop_load

disable_load_job

disable_streaming_preaggregations

div_precision_increment

dpp_bytes_per_reduce

dpp_config_str

dpp_default_cluster

dpp_default_config_str

dpp_hadoop_client_path

drop_backend_after_decommission

This configuration is used to control whether the system drops the BE after successfully decommissioning the BE. If true, the BE node will be deleted after the BE is successfully offline. If false, after the BE successfully goes offline, the BE will remain in the DECOMMISSION state, but will not be dropped.

This configuration can play a role in certain scenarios. Assume that the initial state of a Doris cluster is one disk per BE node. After running for a period of time, the system has been vertically expanded, that is, each BE node adds 2 new disks. Because Doris currently does not support data balancing among the disks within the BE, the data volume of the initial disk may always be much higher than the data volume of the newly added disk. At this time, we can perform manual inter-disk balancing by the following operations:

  1. Set the configuration item to false.
  2. Perform a decommission operation on a certain BE node. This operation will migrate all data on the BE to other nodes.
  3. After the decommission operation is completed, the BE will not be dropped. At this time, cancel the decommission status of the BE. Then the data will start to balance from other BE nodes back to this node. At this time, the data will be evenly distributed to all disks of the BE.
  4. Perform steps 2 and 3 for all BE nodes in sequence, and finally achieve the purpose of disk balancing for all nodes.

dynamic_partition_check_interval_seconds

dynamic_partition_enable

edit_log_port

edit_log_roll_num

edit_log_type

enable_auth_check

enable_batch_delete_by_default

Whether to add a delete sign column when create unique table

enable_deploy_manager

enable_insert_strict

enable_local_replica_selection

enable_materialized_view

This configuration is used to turn on and off the creation of materialized views. If set to true, the function to create a materialized view is enabled. The user can create a materialized view through the CREATE MATERIALIZED VIEW command. If set to false, materialized views cannot be created.

If you get an error The materialized view is coming soon or The materialized view is disabled when creating the materialized view, it means that the configuration is set to false and the function of creating the materialized view is turned off. You can start to create a materialized view by modifying the configuration to true.

This variable is a dynamic configuration, and users can modify the configuration through commands after the FE process starts. You can also modify the FE configuration file and restart the FE to take effect.

enable_metric_calculator

enable_spilling

enable_token_check

es_state_sync_interval_second

event_scheduler

exec_mem_limit

export_checker_interval_second

export_running_job_num_limit

export_tablet_num_per_task

export_task_default_timeout_second

expr_children_limit

expr_depth_limit

force_do_metadata_checkpoint

forward_to_master

frontend_address

hadoop_load_default_timeout_second

heartbeat_mgr_blocking_queue_size

heartbeat_mgr_threads_num

history_job_keep_max_second

http_backlog_num

The backlog_num for netty http server, When you enlarge this backlog_num, you should enlarge the value in the linux /proc/sys/net/core/somaxconn file at the same time

mysql_nio_backlog_num

The backlog_num for mysql nio server, When you enlarge this backlog_num, you should enlarge the value in the linux /proc/sys/net/core/somaxconn file at the same time

http_port

HTTP bind port. Defaults to 8030.

http_max_line_length

The max length of an HTTP URL. The unit of this configuration is BYTE. Defaults to 4096.

http_max_header_size

The max size of allowed HTTP headers. The unit of this configuration is BYTE. Defaults to 8192.

ignore_meta_check

init_connect

insert_load_default_timeout_second

interactive_timeout

is_report_success

label_clean_interval_second

label_keep_max_second

language

license

load_checker_interval_second

load_etl_thread_num_high_priority

load_etl_thread_num_normal_priority

load_input_size_limit_gb

load_mem_limit

load_pending_thread_num_high_priority

load_pending_thread_num_normal_priority

load_running_job_num_limit

load_straggler_wait_second

locale

log_roll_size_mb

lower_case_table_names

master_sync_policy

max_agent_task_threads_num

max_allowed_in_element_num_of_delete

This configuration is used to limit element num of InPredicate in delete statement. The default value is 1024.

max_allowed_packet

max_backend_down_time_second

max_balancing_tablets

max_bdbje_clock_delta_ms

max_broker_concurrency

max_bytes_per_broker_scanner

max_clone_task_timeout_sec

Type: long Description: Used to control the maximum timeout of a clone task. The unit is second. Default value: 7200 Dynamic modification: yes

Can cooperate with mix_clone_task_timeout_sec to control the maximum and minimum timeout of a clone task. Under normal circumstances, the timeout of a clone task is estimated by the amount of data and the minimum transfer rate (5MB/s). In some special cases, these two configurations can be used to set the upper and lower bounds of the clone task timeout to ensure that the clone task can be completed successfully.

max_connection_scheduler_threads_num

max_conn_per_user

max_create_table_timeout_second

max_distribution_pruner_recursion_depth

max_layout_length_per_row

max_load_timeout_second

max_mysql_service_task_threads_num

max_query_retry_time

max_routine_load_job_num

max_routine_load_task_concurrent_num

max_routine_load_task_num_per_be

max_running_rollup_job_num_per_table

max_running_txn_num_per_db

This configuration is mainly used to control the number of concurrent load jobs of the same database.

When there are too many load jobs running in the cluster, the newly submitted load jobs may report errors:

  1. current running txns on db xxx is xx, larger than limit xx

When this error is encountered, it means that the load jobs currently running in the cluster exceeds the configuration value. At this time, it is recommended to wait on the business side and retry the load jobs.

Generally it is not recommended to increase this configuration value. An excessively high number of concurrency may cause excessive system load.

max_scheduling_tablets

max_small_file_number

max_small_file_size_bytes

max_stream_load_timeout_second

This configuration is specifically used to limit timeout setting for stream load. It is to prevent that failed stream load transactions cannot be canceled within a short time because of the user’s large timeout setting.

max_tolerable_backend_down_num

max_unfinished_load_job

metadata_checkopoint_memory_threshold

metadata_failure_recovery

meta_delay_toleration_second

meta_dir

meta_publish_timeout_ms

min_bytes_per_broker_scanner

min_clone_task_timeout_sec

Type: long Description: Used to control the minimum timeout of a clone task. The unit is second. Default value: 180 Dynamic modification: yes

See the description of max_clone_task_timeout_sec.

mini_load_default_timeout_second

min_load_timeout_second

mysql_service_io_threads_num

mysql_service_nio_enabled

net_buffer_length

net_read_timeout

net_write_timeout

parallel_exchange_instance_num

parallel_fragment_exec_instance_num

period_of_auto_resume_min

plugin_dir

plugin_enable

priority_networks

proxy_auth_enable

proxy_auth_magic_prefix

publish_version_interval_ms

publish_version_timeout_second

qe_max_connection

qe_slow_log_ms

query_cache_size

query_cache_type

query_colocate_join_memory_limit_penalty_factor

query_port

query_timeout

remote_fragment_exec_timeout_ms

replica_ack_policy

replica_delay_recovery_second

replica_sync_policy

report_queue_size

resource_group

rewrite_count_distinct_to_bitmap_hll

This variable is a session variable, and the session level takes effect.

  • Type: boolean
  • Description: Only for the table of the AGG model, when the variable is true, when the user query contains aggregate functions such as count(distinct c1), if the type of the c1 column itself is bitmap, count distnct will be rewritten It is bitmap_union_count(c1). When the type of the c1 column itself is hll, count distinct will be rewritten as hll_union_agg(c1) If the variable is false, no overwriting occurs.
  • Default value: true.

rpc_port

schedule_slot_num_per_path

small_file_dir

SQL_AUTO_IS_NULL

sql_mode

sql_safe_updates

sql_select_limit

storage_cooldown_second

storage_engine

storage_flood_stage_left_capacity_bytes

storage_flood_stage_usage_percent

storage_high_watermark_usage_percent

storage_min_left_capacity_bytes

stream_load_default_timeout_second

sys_log_delete_age

sys_log_dir

sys_log_level

sys_log_roll_interval

sys_log_roll_mode

sys_log_roll_num

sys_log_verbose_modules

system_time_zone

tablet_create_timeout_second

tablet_delete_timeout_second

tablet_repair_delay_factor_second

tablet_stat_update_interval_second

test_materialized_view

thrift_backlog_num

thrift_client_timeout_ms

The connection timeout and socket timeout config for thrift server.

The value for thrift_client_timeout_ms is set to be larger than zero to prevent some hang up problems in java.net.SocketInputStream.socketRead0.

thrift_server_max_worker_threads

time_zone

tmp_dir

transaction_clean_interval_second

tx_isolation

txn_rollback_limit

use_new_tablet_scheduler

use_v2_rollup

using_old_load_usage_pattern

Variable Info

version

version_comment

wait_timeout

with_k8s_certs

enable_strict_storage_medium_check

This configuration indicates that when the table is being built, it checks for the presence of the appropriate storage medium in the cluster. For example, when the user specifies that the storage medium is’ SSD ‘when the table is built, but only’ HDD ‘disks exist in the cluster,

If this parameter is’ True ‘, the error ‘Failed to find enough host in all Backends with storage medium with storage medium is SSD, need 3’.

If this parameter is’ False ‘, no error is reported when the table is built. Instead, the table is built on a disk with ‘HDD’ as the storage medium.

thrift_server_type

This configuration represents the service model used by The Thrift Service of FE, is of type String and is case-insensitive.

If this parameter is ‘SIMPLE’, then the ‘TSimpleServer’ model is used, which is generally not suitable for production and is limited to test use.

If the parameter is ‘THREADED’, then the ‘TThreadedSelectorServer’ model is used, which is a non-blocking I/O model, namely the master-slave Reactor model, which can timely respond to a large number of concurrent connection requests and performs well in most scenarios.

If this parameter is THREAD_POOL, then the TThreadPoolServer model is used, the model for blocking I/O model, use the thread pool to handle user connections, the number of simultaneous connections are limited by the number of thread pool, if we can estimate the number of concurrent requests in advance, and tolerant enough thread resources cost, this model will have a better performance, the service model is used by default.

cache_enable_sql_mode

If this switch is turned on, the SQL query result set will be cached. If the interval between the last visit version time in all partitions of all tables in the query is greater than cache_last_version_interval_second, and the result set is less than cache_result_max_row_count, the result set will be cached, and the next same SQL will hit the cache.

cache_enable_partition_mode

When this switch is turned on, the query result set will be cached according to the partition. If the interval between the query table partition time and the query time is less than cache_last_version_interval_second, the result set will be cached according to the partition.

Part of the data will be obtained from the cache and some data from the disk when querying, and the data will be merged and returned to the client.

cache_last_version_interval_second

The time interval of the latest partitioned version of the table refers to the time interval between the data update and the current version. It is generally set to 900 seconds, which distinguishes offline and real-time import.

cache_result_max_row_count

In order to avoid occupying too much memory, the maximum number of rows that can be cached is 2000 by default. If this threshold is exceeded, the cache cannot be set.

recover_with_empty_tablet

In some very special circumstances, such as code bugs, or human misoperation, etc., all replicas of some tablets may be lost. In this case, the data has been substantially lost. However, in some scenarios, the business still hopes to ensure that the query will not report errors even if there is data loss, and reduce the perception of the user layer. At this point, we can use the blank Tablet to fill the missing replica to ensure that the query can be executed normally.

Set to true so that Doris will automatically use blank replicas to fill tablets which all replicas have been damaged or missing.

Default is false.

default_db_data_quota_bytes

Used to set default database data quota size, default is 1T.

default_max_filter_ratio

Used to set default max filter ratio of load Job. It will be overridden by max_filter_ratio of the load job properties,default value is 0, value range 0-1.

enable_http_server_v2

Whether to enable the V2 version of the HTTP Server implementation. The new HTTP Server is implemented using SpringBoot. And realize the separation of front and back ends. Only when it is turned on, can you use the new UI interface under the ui/ directory.

Default is false.

http_api_extra_base_path

In some deployment environments, user need to specify an additional base path as the unified prefix of the HTTP API. This parameter is used by the user to specify additional prefixes. After setting, user can get the parameter value through the GET /api/basepath interface. And the new UI will also try to get this base path first to assemble the URL. Only valid when enable_http_server_v2 is true.

The default is empty, that is, not set.