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-level parameters for syslog control.
| Parameter | Default value | Description |
|---|---|---|
| enable_syslog_recycle | False | Specifies whether to enable syslog recycling. For more information about the enable_syslog_recycle parameter, see enable_syslog_recycle. |
| enable_syslog_wf | True | Specifies whether to write syslogs above the WARN level to a .wf log file. For more information about the enable_syslog_wf parameter, see enable_syslog_wf. |
| enable_async_syslog | True | Specifies whether to enable asynchronous syslog write for observer.log, election.log, and rootservice.log. For more information about the enable_async_syslog parameter, see enable_async_syslog. |
| max_syslog_file_count | 0 | The maximum number of syslog files that can be retained. For more information about the max_syslog_file_count parameter, see max_syslog_file_count. |
| 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. For more information about the syslog_io_bandwidth_limit parameter, see syslog_io_bandwidth_limit. |
| syslog_level | WDIAG | The level of syslogs. For more information about the syslog_level parameter, see syslog_level. |
| syslog_disk_size | 0M | The maximum disk space available for syslogs. When the total size of existing syslogs is about to reach the specified upper limit, the syslog files are deleted from the oldest ones, including those that are compressed. For more information about the syslog_disk_size parameter, see syslog_disk_size. |
| syslog_compress_func | none | The compression algorithm for syslogs. For more information about the syslog_compress_func parameter, see syslog_compress_func. |
| syslog_file_uncompressed_count | 0 | The number of syslog files that are not compressed. This parameter takes effect only when syslog_compress_func is not set to none. The number of syslog files is separately counted for each syslog file type. For more information about the syslog_file_uncompressed_count parameter, see syslog_file_uncompressed_count. |
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.