====== FastDPI monitoring and logs ======
{{indexmenu_n>12}}
  * [[en:dpi:dpi_components:platform:mon_stat:snmpd]]
  * [[en:dpi:dpi_components:platform:mon_stat:zabbix]]
  * [[en:dpi:dpi_components:platform:mon_stat:traffic_distribution]]

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System logs are presented as text files that are located in the /var/log/dpi directory for DPI and PCRF modules.
Types of messages in the log:
  - [CRITICAL] - critical error, system operation is impossible without troubleshooting
  - [WARNING] - warning, the system does not stop, but it is worth eliminating this malfunction
  - [TRACE] - messages when the diagnostic trace mode is enabled
  - [INFO] - notification of system actions
  - [ERROR] - error when connecting services and policies, incorrect configuration

The FastDPI process by default logs all system actions to the following debug and statistics log files:
  - [[en:dpi:dpi_components:platform:mon_stat:slave_log|/var/log/dpi/fastdpi_slave.log]] - a log of traffic processing processes((For each handler, its own fastdpi_slave log is created, other log files are created in a single copy.))
  - [[en:dpi:dpi_components:platform:mon_stat:stat_log| /var/log/dpi/fastdpi_stat.log]] - traffic processing statistics log
  - [[en:dpi:dpi_components:platform:mon_stat:alert_log| /var/log/dpi/fastdpi_alert.log]] - common fastDPI functions log

[[en:dpi:dpi_components:platform:mon_stat:admin_stat_log_block| Blocking counters that are saved in the statistics log]]

===== Log file rotation =====
File rotation provides a daily backup of the daily log. By default, this process is performed during the hours with the lowest system load. The log storage depth is defined in the configuration of ''/etc/logrotate.d/fastdpi'' by the parameter ''maxage'', the value is specified **in days**.