max_syslog_file_count

Description

max_syslog_file_count specifies the maximum number of log files that can be retained before they are recycled.

Privilege requirements

• Query the parameter

  The sys tenant and all user tenants can query this parameter by using the SHOW PARAMETERS statement or the GV$OB_PARAMETERS view.

• Modify the parameter

  Only the sys tenant can modify this parameter. User tenants cannot modify this parameter.

Attributes

Usage instructions

• The total number of all types of log files is limited by max_syslog_file_count, and the FIFO (First-In, First-Out) strategy is used for log file eviction. The FIFO strategy determines the eviction order based on the last modification time of the log files. For example, files like xxxxxxxx.log.20231123223441234 are sorted by their ending timestamp to decide which files are deleted first.

• The file retention rule is as follows: The total number of all rotated xxxxxx.log.xxxxx files is limited by the value of max_syslog_file_count, and the same limit applies to all rotated xxxxxx.log.wf.xxxxx files. Note that currently active log files being written (such as observer.log, rootservice.log) and their corresponding WF files are not included in this count.

• If Trace logs are generated too quickly and in large quantities, they may occupy space intended for OBServer log files, causing OBServer logs to be evicted earlier than expected. In such cases, it is recommended to adjust the full-link tracing level to control the amount of logs generated. For details about Trace log levels, see End-to-end tracing methods.

• The relationship between the parameters max_syslog_file_count and syslog_disk_size is as follows:

  1. max_syslog_file_count=0, syslog_disk_size=0: No log recycling occurs until the disk is full.
  2. max_syslog_file_count=0, syslog_disk_size>0: When the total log size approaches syslog_disk_size, the oldest log files are deleted to free up space.
  3. max_syslog_file_count>0, syslog_disk_size=0: When the number of a certain type of log file exceeds max_syslog_file_count, the oldest log files are deleted to free up space.
  4. max_syslog_file_count>0, syslog_disk_size>0: When the number of a certain type of log file exceeds max_syslog_file_count, or when the total log size approaches syslog_disk_size, the oldest compressed files are deleted.

Examples

Set the maximum number of log files that can be retained before they are recycled to 20.

obclient> ALTER SYSTEM SET max_syslog_file_count=20;

References

• Logs

• ob_esi_max_syslog_file_count