Logging Time

client_min_messages

Parameter description: Specifies which level of messages are sent to the client. Each level covers all the levels following it. The lower the level is, the fewer messages are sent.

Type: USERSET

When the values of client_min_messages and log_min_messages are the same, the levels are different.

Valid values: Enumerated values. Valid values: debug5, debug4, debug3, debug2, debug1, info, log, notice, warning, error For details about the parameters, see Table 1.

Default value: notice

log_min_messages

Parameter description: Specifies which level of messages will be written into server logs. Each level covers all the levels following it. The lower the level is, the fewer messages will be written into the log.

Type: SUSET

When the values of client_min_messages and log_min_messages are the same, the levels are different.

Value range: enumerated type. Valid values: debug5, debug4, debug3, debug2, debug1, info, log, notice, warning, error, fatal, panic For details about the parameters, see Table 1.

Default value: warning

log_min_error_statement

Parameter description: Specifies which SQL statements that cause errors condition will be recorded in the server log.

Type: SUSET

The default is error, indicating that statements causing errors, log messages, fatal errors, or panics will be logged.
panic: This feature is disabled.

Default value: error

log_min_duration_statement

Parameter description: Specifies the threshold for logging statement execution durations. The execution duration that is greater than the specified value will be logged.

This parameter helps track query statements that need to be optimized. For clients using extended query protocol, durations of the Parse, Bind, and Execute are logged independently.

Type: SUSET

If this parameter and log_statement are used at the same time, statements recorded based on the value of log_statement will not be logged again after their execution duration exceeds the value of this parameter. If you are not using syslog, it is recommended that you log the process ID (PID) or session ID using log_line_prefix so that you can link the current statement message to the last logged duration.

Value range: an integer ranging from -1 to INT_MAX. The unit is millisecond.

If this parameter is set to 250, execution durations of SQL statements that run 250 ms or longer will be logged.
0: Execution durations of all the statements are logged.
–1: This feature is disabled.

Default value: 30min

backtrace_min_messages

Parameter description: Prints the function's stack information to the server's log file if the level of information generated is greater than or equal to this parameter level.

Type: SUSET

This parameter is used for locating customer on-site problems. Because frequent stack printing will affect the system's overhead and stability, therefore, when you locate the onsite problems, set the value of this parameter to ranks other than fatal and panic.

Value range: enumerated values

Valid values: debug5, debug4, debug3, debug2, debug1, info, log, notice, warning, error, fatal, panic For details about the parameters, see Table 1.

Default value: panic

Table 1 explains the message security levels used in GaussDB(DWS). If logging output is sent to syslog or eventlog, severity is translated in GaussDB(DWS) as shown in the table.

**Table 1** Message Severity Levels
Severity	Description	syslog	eventlog
debug[1-5]	Provides detailed debug information.	DEBUG	INFORMATION
log	Reports information of interest to administrators, for example, checkpoint activity.	INFO	INFORMATION
info	Provides information implicitly requested by the user, for example, output from VACUUM VERBOSE.	INFO	INFORMATION
notice	Provides information that might be helpful to users, for example, notice of truncation of long identifiers and index created as part of the primary key.	NOTICE	INFORMATION
warning	Provides warnings of likely problems, for example, COMMIT outside a transaction block.	NOTICE	WARNING
error	Reports an error that causes a command to terminate.	WARNING	ERROR
fatal	Reports the reason that causes a session to terminate.	ERR	ERROR
panic	Reports an error that caused all database sessions to terminate.	CRIT	ERROR

plog_merge_age

Parameter description: Specifies the output interval of performance log data.

Type: SUSET

This parameter value is in milliseconds. You are advised to set this parameter to a value that is a multiple of 1000. That is, the value is in seconds. Name extension of the performance log files controlled by this parameter is .prf. These log files are stored in the $GAUSSLOG/gs_profile/<node_name> directory. node_name is the value of pgxc_node_name in the postgres.conf file. You are advised not to use this parameter externally.

Value range: an integer ranging from 0 to INT_MAX. The unit is millisecond (ms).

0 indicates that the current session will not output performance log data.
A value other than 0 indicates the output interval of performance log data. The smaller the value is, the more log data is output, resulting in more negative impact on the performance.

Default value: 3s

profile_logging_module

Parameter description: Specifies the type of performance logs. When using this parameter, ensure that the value of plog_merge_age is not 0. This parameter is a session-level parameter, and you are not advised to use the gs_guc tool to set it. Only clusters of 8.1.3 and later versions support this function.

Type: USERSET

Value range: a string

Default value: OBS, HADOOP and REMOTE_DATANODE are enabled. MD is disabled. You can run the SHOW profile_logging_module command to view the value.

Setting method: First, you can run SHOW profile_logging_module to view which module is controllable. For example, the query output result is as follows:

    
         show profile_logging_module;
profile_logging_module
--------------------------------------------
ALL,on(OBS,HADOOP,REMOTE_DATANODE),off(MD)(1 row)

Open the MD performance log and view the setting. The ALL identifier is equivalent to a shortcut operation. That is, logs of all modules can be enabled or disabled.

    
         set profile_logging_module='on(md)';
SET

show profile_logging_module;
profile_logging_module
---------------------------------------------
ALL,on(MD,OBS,HADOOP,REMOTE_DATANODE),off()(1 row)