You can configure cluster-level parameters, tenant-level system variables, SQL hints, and semaphores for syslog management and control.
Control by using parameters
The following table describes the cluster parameters that control syslogs.
| Parameter | Default value | Description |
|---|---|---|
| enable_syslog_recycle | False | Specifies whether to enable syslog recycling. |
| enable_syslog_wf | True | Specifies whether to write syslogs above the WARN level to a .wf log file. |
| enable_async_syslog | True | Specifies whether to enable asynchronous syslog write for observer.log, election.log, and rootservice.log. |
| max_syslog_file_count | 0 | The maximum number of syslog files that can be retained. |
| syslog_io_bandwidth_limit | 30MB | The maximum I/O bandwidth available for syslogs. If the specified upper limit is reached, the remaining syslogs are discarded. The value 0 specifies to disable syslogs. |
| syslog_level | WDIAG | The level of syslogs. |
| syslog_disk_size | 0M | The maximum disk space available for syslogs. When the total size of syslogs is close to the value specified by this parameter, the earliest log file is deleted, regardless of whether it is compressed. |
| syslog_compress_func | none | The compression algorithm for syslogs. |
| syslog_file_uncompressed_count | 0 | The number of syslog files that are not compressed. This parameter is valid only when the syslog_compress_func parameter is set to a value other than none. The number of uncompressed syslog files is counted separately for each syslog type. |
| alert_log_level | INFO | The level of alert logs. |
Control by using system variables
The tenant-level system variable ob_log_level controls the level of session-level logs. For more information about the ob_log_level system variable, see ob_log_level.