IoTDB Log Overview

Description

Log Description

Log paths: The default storage paths of IoTDB logs are /var/log/Bigdata/iotdb/confignode and /var/log/Bigdata/iotdb/iotdbserver (for run logs) as well as /var/log/Bigdata/audit/iotdb/iotdbserver (for audit logs).

Log archive rule: The automatic compression and archiving function of IoTDB is enabled. By default, when the size of a log file exceeds 20 MB (which is adjustable), the log file is automatically compressed. The naming rule of the compressed log file is as follows: <Original log file name>-<yyyymmdd>.ID.log.gz. A maximum of 10 latest compressed files are reserved. The number of compressed files and compression threshold can be configured.

**Table 1** IoTDB log list
Type	Name	Description
ConfigNode run log	log_confignode_all.log	ConfigNode instance all log
	log_confignode_error.log	ConfigNode instance error log
	log-measure.log	ConfigNode instance monitoring log
	log-query-debug.log	ConfigNode query debug log
	log-query-frequency.log	ConfigNode query frequency log
	log-sync.log	ConfigNode synchronization log
	log-slow-sql.log	ConfigNode slow SQL log
	server.out	ConfigNode instance startup exception log
	postinstall.log	ConfigNode process startup log
	prestart.log	ConfigNode process startup exception log
	service-healthcheck.log	IoTDB database initialization log.
	start.log	ConfigNode instance startup log
	stop.log	ConfigNode instance stopping log
	ConfigNode-threadDump-<timestamp>.log	ConfigNode instance stack log
	ConfigNode-gc.log.0.current	ConfigNode instance GC log
IoTDBServer run log	log_datanode_all.log	IoTDBServer instance all log
	log_datanode_error.log	IoTDBServer instance error log
	log_datanode_measure.log	IoTDBServer instance monitoring log
	log_datanode_query_debug.log	IoTDBServer query debug log
	log_datanode_query_frequency.log	IoTDBServer query frequency log
	log_datanode_sync.log	IoTDBServer synchronization log
	log_datanode_slow_sql.log	IoTDBServer slow SQL log
	server.out	IoTDBServer instance startup exception log
	postinstall.log	IoTDBServer process startup log
	prestart.log	IoTDBServer process startup exception log
	service-healthcheck.log	IoTDB database initialization log.
	start.log	IoTDBServer instance startup log
	stop.log	IoTDBServer instance stopping log
	IoTDBServer-threadDump-<timestamp>.log	IoTDBServer instance stack log
	IoTDBServer-gc.log.0.current	IoTDBServer instance GC log
ConfigNode audit log	log_audit.log	ConfigNode audit log
IoTDBServer audit log	log_audit.log	IoTDBServer audit log

Log levels

Table 2 describes the log levels supported by IoTDB.

Levels of logs are ERROR, WARN, INFO, and DEBUG from the highest to the lowest priority. Run logs of equal or higher levels are recorded. The higher the specified log level, the fewer the logs recorded.

**Table 2** Log levels
Level	Description
ERROR	Logs of this level record error information about system running.
WARN	Logs of this level record exception information about the current event processing.
INFO	Logs of this level record normal running status information about the system and events.
DEBUG	Logs of this level record the system information and system debugging information.

To modify log levels, perform the following operations:

Go to the All Configurations page of the IoTDB service by referring to Modifying Cluster Service Configuration Parameters.
In the navigation tree on the left, select Log corresponding to the role to be modified.
Select a desired log level and save the configuration.

The IoTDB log level takes effect 60 seconds after being configured. You do not need to restart the service.

Log Formats

The following table lists the IoTDB log formats:

**Table 3** Log formats
Type	Format	Example
Run log	<yyyy-MM-dd HH:mm:ss,SSS> \| Log level \| [Thread name] \| Log information \| Log printing class (File:Line number)	2021-06-08 10:08:41,221 \| ERROR \| [main] \| Client failed to open SaslClientTransport to interact with a server during session initiation: \| org.apache.iotdb.rpc.sasl.TFastSaslTransport (TFastSaslTransport.java:257)
Audit log	<yyyy-MM-dd HH:mm:ss,SSS> \| Log level \| [Thread name] \| Log information \| Log printing class (File:Line number)	2021-06-08 11:03:49,365 \| INFO \| [ClusterClient-1] \| Session-1 is closing \| IoTDB_AUDIT_LOGGER (TSServiceImpl.java:326)