Cluster Setup

For installation prerequisites, please refer to Installation Prerequisites

Start Service

Users can build clusters in pseudo-distributed mode or distributed mode. The main difference between pseudo-distributed mode and distributed mode is the difference in seed_nodes in the configuration file. For detail descriptions, please refer to [Cluster Configuration Items](#Cluster Configuration Items).

To start the service of one of the nodes, you need to execute the following commands:

  1. # Unix/OS X
  2. > nohup sbin/start-node.sh >/dev/null 2>&1 &
  3. or
  4. > nohup sbin/start-node.sh -c <conf_path> -internal_meta_port 9003 >/dev/null 2>&1 &
  6. # Windows
  7. > nohup sbin/start-node.bat
  8. or
  9. > nohup sbin/start-node.bat -c <conf_path> -internal_meta_port 9003

-c <conf_path> use the configuration file in the conf_path folder to override the default configuration file; -internal_meta_port 9003 overrides the specific configuration item internal_meta_port. The currently supported items to overwrite the original configurations when starting IoTDB are the followings : internal_meta_port, internal_data_port, cluster_rpc_port, seed_nodes. When both exist, the specified configuration item will overwrite the configurations in the configuration file.

Cluster Configuration Items

Before starting to use IoTDB, you need to config the configuration files first. For your convenience, we have already set the default config in the files.

In total, we provide users four kinds of configurations module:

  • environment configuration file (iotdb-env.bat, iotdb-env.sh). The default configuration file for the environment configuration item. Users can configure the relevant system configuration items of JAVA-JVM in the file.

  • system configuration file (iotdb-engine.properties). The default configuration file for the IoTDB engine layer configuration item. Users can configure the IoTDB engine related parameters in the file, such as the precision of timestamp(timestamp_precision), etc. What’s more, Users can configure settings of TsFile (the data files), such as the data size written to the disk per time(group_size_in_byte).

  • log configuration file (logback.xml). The default log configuration file, such as the log levels.

  • iotdb-cluster.properties. Some configurations required by IoTDB cluster. Such as replication number(default_replica_num), etc.

For detailed description of the two configuration files iotdb-engine.properties, cluster-env.sh/cluster-env.bat, please refer to Configuration Manual. The configuration items described below are in the iotdb-cluster.properties file.

  • internal_meta_port
Nameinternal_meta_port
DescriptionIoTDB meta service port, for meta group’s communication, which involves all nodes and manages the cluster configuration and storage groups. IoTDB will automatically create a heartbeat port for each meta service. The default meta service heartbeat port is internal_meta_port+1, please confirm that these two ports are not reserved by the system and are not occupied
TypeInt32
Default9003
EffectiveAfter restart system, shall NOT change after cluster is up
  • internal_data_port
Nameinternal_data_port
DescriptionIoTDB data service port, for data groups’ communication, each consists of one node and its replicas, managing timeseries schemas and data. IoTDB will automatically create a heartbeat port for each data service. The default data service heartbeat port is internal_data_port+1. Please confirm that these two ports are not reserved by the system and are not occupied
TypeInt32
Default40010
EffectiveAfter restart system, shall NOT change after cluster is up
  • cluster_rpc_port
Namecluster_rpc_port
DescriptionThe port used to communicate with the clients (JDBC, CLI, Session API…), please confirm that the port is not reserved by the system and is not occupied
TypeInt32
Default55560
EffectiveAfter restart system
  • seed_nodes
Nameseed_nodes
DescriptionThe address of the nodes in the cluster, {IP/DOMAIN}:internal_meta_port:internal_data_port format, separated by commas; for the pseudo-distributed mode, you can fill in localhost, or 127.0.0.1 or mixed, but the real ip address cannot appear; for the distributed mode, real ip or hostname is supported, but localhost or 127.0.0.1 cannot appear. When used by start-node.sh(.bat), this configuration means the nodes that will form the initial cluster, so every node that use start-node.sh(.bat) should have the same seed_nodes, or the building of the initial cluster will fail. WARNING: if the initial cluster is built, this should not be changed before the environment is cleaned. When used by add-node.sh(.bat), this means the nodes to which that the application of joining the cluster will be sent, as all nodes can respond to a request, this configuration can be any nodes that already in the cluster, unnecessary to be the nodes that were used to build the initial cluster by start-node.sh(.bat). Several nodes will be picked randomly to send the request, the number of nodes picked depends on the number of retries.
TypeString
Default127.0.0.1:9003:40010,127.0.0.1:9005:40012,127.0.0.1:9007:40014
EffectiveAfter restart system
  • rpc_thrift_compression_enable
Namerpc_thrift_compression_enable
DescriptionWhether to enable thrift compression, Note that this parameter should be consistent with each node and with the client, and also consistent with the rpc_thrift_compression_enable parameter in iotdb-engine.properties
TypeBoolean
Defaultfalse
EffectiveAfter restart system, must be changed with all other nodes
  • default_replica_num
Namedefault_replica_num
DescriptionNumber of cluster replicas of timeseries schema and data. Storage group info is always fully replicated in all nodes.
TypeInt32
Default2
EffectiveAfter restart system, shall NOT change after cluster is up
  • cluster_name
Namecluster_name
DescriptionCluster name is used to identify different clusters, cluster_name of all nodes in a cluster must be the same
TypeString
Defaultdefault
EffectiveAfter restart system
  • connection_timeout_ms
Nameconnection_timeout_ms
DescriptionHeartbeat timeout time period between nodes in the same raft group, in milliseconds
TypeInt32
Default20000
EffectiveAfter restart system
  • read_operation_timeout_ms
Nameread_operation_timeout_ms
DescriptionRead operation timeout time period, for internal communication only, not for the entire operation, in milliseconds
TypeInt32
Default30000
EffectiveAfter restart system
  • write_operation_timeout_ms
Namewrite_operation_timeout_ms
DescriptionThe write operation timeout period, for internal communication only, not for the entire operation, in milliseconds
TypeInt32
Default30000
EffectiveAfter restart system
  • min_num_of_logs_in_mem
Namemin_num_of_logs_in_mem
DescriptionThe minimum number of committed logs in memory, after each log deletion, at most such number of logs will remain in memory. Increasing the number will reduce the chance to use snapshot in catch-ups, but will also increase the memory footprint
TypeInt32
Default100
EffectiveAfter restart system
  • max_num_of_logs_in_mem
Namemax_num_of_logs_in_mem
DescriptionMaximum number of committed logs in memory, when reached, a log deletion will be triggered. Increasing the number will reduce the chance to use snapshot in catch-ups, but will also increase memory footprint
TypeInt32
Default1000
EffectiveAfter restart system
  • log_deletion_check_interval_second
Namelog_deletion_check_interval_second
DescriptionThe interval for checking and deleting the committed log task, which removes oldest in-memory committed logs when their size exceeds min_num_of_logs_in_mem , in seconds
TypeInt32
Default60
EffectiveAfter restart system
  • enable_auto_create_schema
Nameenable_auto_create_schema
DescriptionWhether creating schema automatically is enabled, this will replace the one in iotdb-engine.properties
TypeBOOLEAN
Defaulttrue
EffectiveAfter restart system
  • consistency_level
Nameconsistency_level
DescriptionConsistency level, now three consistency levels are supported: strong, mid, and weak. Strong consistency means the server will first try to synchronize with the leader to get the newest data, if failed(timeout), directly report an error to the user; While mid consistency means the server will first try to synchronize with the leader, but if failed(timeout), it will give up and just use current data it has cached before; Weak consistency does not synchronize with the leader and simply use the local data
Typestrong, mid, weak
Defaultmid
EffectiveAfter restart system
  • is_enable_raft_log_persistence
Nameis_enable_raft_log_persistence
DescriptionWhether to enable raft log persistence
TypeBOOLEAN
Defaulttrue
EffectiveAfter restart system

Enable GC log

GC log is off by default. For performance tuning, you may want to collect the GC info.

To enable GC log, just add a parameter printgc when you start the server.

  1. nohup sbin/start-node.sh printgc >/dev/null 2>&1 &

Or

  1. sbin\start-node.bat printgc

GC log is stored at IOTDB_HOME/logs/gc.log.