NXLog User Guide

109.14. Internal (im_internal)

NXLog produces its own logs about its operations, including errors and debug messages. This module makes it possible to insert those internal log messages into a route. Internal messages can also be generated from the NXLog language using the log_info(), log_warning(), and log_error() procedures.

Note	Only messages with log level INFO and above are supported. Debug messages are ignored due to technical reasons. For debugging purposes the direct logging facility should be used: see the global LogFile and LogLevel directives.

Warning

One must be careful about the use of the im_internal module because it is easy to cause message loops. For example, consider the situation when internal log messages are sent to a database. If the database is experiencing errors which result in internal error messages, then these are again routed to the database and this will trigger further error messages, resulting in a loop. In order to avoid a resource exhaustion, the im_internal module will drop its messages when the queue of the next module in the route is full. It is recommended to always put the im_internal module instance in a separate route.

Note	If internal messages are required in Syslog format, they must be explicitly converted with pm_transformer or the to_syslog_bsd() procedure of the xm_syslog module, because the $raw_event field is not generated in Syslog format.

109.14.1. Configuration

The im_internal module accepts only the common module directives.

109.14.2. Fields

The following fields are used by im_internal.

$raw_event (type: string): The string passed to the log_info() or other log_* procedure.

$ErrorCode (type: integer): The error number provided by the Apache portable runtime library, if an error is logged resulting from an operating system error.

$EventTime (type: datetime): The current time.

$Hostname (type: string): The hostname where the log was produced.

$Message (type: string): The same value as $raw_event.

$ProcessID (type: integer): The process ID of the NXLog process.

$Severity (type: string): The severity name of the event.

$SeverityValue (type: integer): Depending on the log level of the internal message, the value corresponding to "debug", "info", "warning", "error", or "critical".

$SourceName (type: string): Set to nxlog.

109.14.3. Examples

Example 552. Forwarding Internal Messages over Syslog UDP

This configuration collects NXLog internal messages, adds BSD Syslog headers, and forwards via UDP.

nxlog.conf


  1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18

  <Extension syslog>
    Module  xm_syslog
</Extension>

<Input internal>
    Module  im_internal
</Input>

<Output udp>
    Module  om_udp
    Host    192.168.1.1
    Port    514
    Exec    to_syslog_bsd();
</Output>

<Route internal_to_udp>
    Path    internal => udp
</Route>