This chapter describes how modules are loaded in syslog-ng Open Source Edition.

The syslog-ng Open Source Edition application loads every available module during startup.

To load a module that is not loaded automatically, include the following statement in the syslog-ng OSE configuration file:

@module <module-name>

Note the following points about the @module statement:

  • The @module statement is a top-level statement, that is, it cannot be nested into any other statement. It is usually used immediately after the @version statement.

  • Every @module statement loads a single module: loading multiple modules requires a separate @module statement for every module.

  • In the configuration file, the @module statement of a module must be earlier than the module is used.

NOTE: To disable loading every module automatically, set the autoload-compiled-modules global variable to 0 in your configuration file:

@define autoload-compiled-modules 0

Note that in this case you have to explicitly load the modules you want to use.

Use the @requires statement to ensure that the specified module is loaded

To ensure that a module is loaded, include the following statement in the syslog-ng OSE configuration file or the external files included in the configuration file:

@requires <module-name>

NOTE: If you include the @requires statement in the:

  • syslog-ng OSE configuration file, syslog-ng OSE attempts to load the required module. If it fails to load the module, syslog-ng OSE stops and an error message is displayed.

  • external files included in the configuration file, syslog-ng OSE attempts to load the required module. If it fails to load the module, only the external file is not processed.

Note that this is not true for modules marked as mandatory. You can make a dependency module mandatory by defining an error message after the @requires <module-name> statement, for example:

@requires http "The http() driver is required for elasticsearch-http(). 
Install syslog-ng-mod-http to continue."

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