Configuring IoTDB Parameters

Scenario

IoTDB uses the multi-replica deployment architecture to implement cluster high availability. Each region (DataRegion and SchemaRegion) has three replicas by default. You can also configure more replicas. If a node is faulty, replicas on other nodes of the region replica can take over services from the faulty node, ensuring service continuity and improving cluster stability.

Procedure

1. Log in to Manager, choose Cluster > Services > IoTDB > Configurations > All Configurations to go to the IoTDB configuration page, and modify the parameters.
2. Modify the ConfigNode and IoTDBServer configurations.
   • Modifying the ConfigNode configuration:
     • Click ConfigNode(Role). You can modify the existing configuration according to Table 1.
     • Choose ConfigNode(Role) > Customization. You can customize ConfigNode configurations in the confignode.customized.configs parameter according to Table 1.
   • Modifying the IoTDBServer configuration:
     • Click IoTDBServer(Role). You can modify the existing configuration according to Table 1.
     • Choose IoTDBServer(Role) > Customization. You can customize IoTDBServer configurations in the engine.customized.configs parameter according to Table 1.

   Table 1 Common parameters

   Parameter	Role	Example Value	Description
   region_data_lost_proportion	ConfigNode	0.5	Region data supplementation starts when the lost data reaches the threshold (50% by default). NOTE: This parameter is available only in MRS 3.3.0 or later.
   region_repair_data_volume	ConfigNode	10	If the data volume in a region exceeds the threshold, the system automatically rectify the fault. The default value is 10 GB. NOTE: This parameter is available only in MRS 3.3.0 or later.
   dest_datanode_remaining_disk_space_proportion	ConfigNode	0.7	Percentage of the region data volume to the remaining disk space of the target DataNode when region replicas are supplemented. The default value is 70%. NOTE: This parameter is available only in MRS 3.3.0 or later.
   read_consistency_level	ConfigNode	strong	Read consistency level. Currently, the value can only be strong or weak. In versions earlier than MRS 3.3.0, you need to set this parameter in the customized parameter confignode.customized.configs.
   flush_proportion	IoTDBServer	0.4	Write memory ratio for invoking disk flushing. If the write load is too high (for example, batch processing = 1000), you can reduce the value.
   replica_affinity_policy	IoTDBServer	random	When the value of read_consistency_level is weak, the strategy of the region replica node is selected for the query task.
   coordinator_read_executor_size	IoTDBServer	20	Number of read thread cores of the IoTDBServer Coordinator of the custom parameter engine.customized.configs
   rpc_thrift_compression_enable	ALL	false	Whether to compress data during transmission. Data is not compressed by default.
   root.log.level	ALL	INFO	IoTDB log level. The modification of this parameter takes effect without restarting related instances.
   SSL_ENABLE	ALL	true	Whether to encrypt the channel between the client and server using SSL

3. Click Save.
4. Click the Instance tab. Select the corresponding instance and choose More > Restart Instance to make the configuration take effect.