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 FusionInsight Manager and choose Cluster > Services > IoTDB. Click Configurations then All Configurations.
2. Enter a parameter name in the search box in the upper right corner and change the parameter value. Table 1 describes common IoTDB parameters.

   Table 1 Common parameters

   Parameter	Role	Default Value	Description
   schema_replication_factor	ConfigNode	3	Number of SchemaRegion replicas. The default value is 3. This parameter can be modified only when the service is installed.
   data_replication_factor	ConfigNode	3	Number of DataRegion replicas. The default value is 3. This parameter can be modified only when the service is installed.
   region_data_lost_proportion	ConfigNode	0.5	Region data supplementation starts when the lost data reaches the threshold (50% by default).
   region_repair_data_volume	ConfigNode	10	If the data volume in a region exceeds the threshold, the system automatically rectifies the fault. The default value is 10 GB.
   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%.
   read_consistency_level	ConfigNode	strong	Read consistency level. Currently, the value can only be strong or weak. strong: strong data consistency weak: weak data consistency
   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	The policy for selecting a region replica node for a query task when read_consistency_level is set to weak. That is, whether a local node is selected or a node is randomly selected from the current cluster. random: a node is randomly selected from the current cluster. local: a local node is selected.
   coordinator_read_executor_size	IoTDBServer	20	Sets the number of read thread cores of IoTDBServer Coordinator. Click IoTDBServer(Role), select Customization, and add the coordinator_read_executor_size parameter and its value to the customized parameter engine.customized.configs.
   rpc_thrift_compression_enable	ALL	false	Whether to enable the RPC Thrift compression function during data transmission. Data is not compressed by default. true: Enable the function. false: Disable the function.
   root.log.level	ALL	INFO	IoTDB log level. The modification of this parameter takes effect without restarting related instances. Log levels include DEBUG, INFO, WARN, ERROR, and OFF.
   SSL_ENABLE	ALL	true	Whether to encrypt the channel between the client and server using SSL true: SSL encryption is enabled. false: SSL encryption is disabled. NOTICE: For clusters with Kerberos authentication enabled (security mode), SSL encryption is enabled by default. For clusters with Kerberos authentication disabled (normal mode), SSL encryption is disabled by default. Disabling SSL encryption is a high-risk operation. Data may be intercepted, which poses security risks. Exercise caution when performing this operation.

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