syslog-ng documentation

Your main source of knowledge

The syslog-ng product family has an extensive documentation, covering everything from how to install a product to the most complex configuration and settings descriptions. If you cannot find an answer to your question, try the mailing list - our community is always eager to help.

syslog-ng Open Source Edition


6.2.1. internal() source options

The internal() driver has the following options:


Type: string

Description: Replaces the ${HOST} part of the message with the parameter string.


Type: number
Default: 100

Description: The size of the initial window, this value is used during flow control. If the max-connections() option is set, the log-iw-size() will be divided by the number of connections, otherwise log-iw-size() is divided by 10 (the default value of the max-connections() option). The resulting number is the initial window size of each connection. For optimal performance when receiving messages from syslog-ng OSE clients, make sure that the window size is larger than the flush-lines() option set in the destination of your clients.

Example 6.6. Initial window size of a connection

If log-iw-size(1000) and max-connections(10), then each connection will have an initial window size of 100.


Accepted values: yes | no
Default: no

Description: If enabled (normalize-hostnames(yes)), syslog-ng OSE converts the hostnames to lowercase.


Type: string

Description: Replaces the ${PROGRAM} part of the message with the parameter string. For example, to mark every message coming from the kernel, include the program-override("kernel") option in the source containing /proc/kmsg.


Type: string

Description: Label the messages received from the source with custom tags. Tags must be unique, and enclosed between double quotes. When adding multiple tags, separate them with comma, for example tags("dmz", "router"). This option is available only in syslog-ng 3.1 and later.


Type: yes or no
Default: no

Description: Add Fully Qualified Domain Name instead of short hostname. This option can be specified globally, and per-source as well. The local setting of the source overrides the global option if available.