This page explains the service features included with YAF.

systemd

On systems that support it, systemd is an option for managing yaf services (as of YAF 2.16.0). The implementation of yaf as a systemd service is intended to provide an easy transition for those migrating from the init.d service implementation.

When running a yaf service for the first time, you must first modify the configuration file, yaf.conf, with relevant parameters for your intended use. If you are upgrading from a previous version of yaf, your configuration file will have persisted during the upgrade. The yaf.conf file is typically found in /etc.

‍ Note: The yaf.conf configuration file in this document sets shell variables that are used when starting yaf, and the file is unrelated to the yaf.init file, written in Lua, that is the argument to yaf's --config option.

Once the configuration file is completed, starting yaf as a service is the same as starting any other systemd service:

# systemctl start yaf.service

Checking the service's status and stopping the service are also typical:

# systemctl status yaf.service

and:

# systemctl stop yaf.service

Instantiated Services

With systemd functionality comes the ability to start a yaf service as an instance, with a unique configuration per instance.

To start YAF as an instantiated service, you must create a unique configuration file in the configuration file directory. The config file should be named yaf.foo.conf where foo is the name you want to give your instantiated service. Once this is done, you can start the instantiated service by passing your service name.

For example:

# systemctl start yaf@foo.service

starts an instantiated service using the configuration file yaf.foo.conf.

init.d

For systems that do not support systemd, the init.d service script is still available, however this capability is not present when installing via rpm.

(For YAF 2.15.0 or earlier, the init.d capability is installed by the rpm and administrators should follow the instructions in this section.)

Running a yaf service using init.d is very similar to using systemd. The yaf.conf configuration file must be configured prior to first use with the parameters you want the service to use. The configuration file is typically located in /etc.

Once your configuration file is complete, you can start the yaf service using the following command:

# service yaf start

You can stop the service or check its status using:

# service yaf stop

and

# service yaf status

The init.d service has one additional feature that does not exist in systemd: dumpstats. This sends a signal to the service telling it write its collection statistics to the yaf log, and the service continues to run. The command has no effect if yaf is not running. It can be called using the command:

# service yaf dumpstats

One can mimic the instantiated services of systemd by creating a configuration file /etc/yaf-foo.conf and either copying or linking /etc/init.d/yaf to /etc/init.d/yaf-foo.

# ln /etc/init.d/yaf /etc/init.d/yaf-foo

Running

# service yaf-foo start

will use the configuration settings in /etc/yaf-foo.conf. This approach should only be used on systems which do not support systemd, and it is not forward-compatible with systemd.